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Fermentation, Volume 9, Issue 6 (June 2023) – 86 articles

Cover Story (view full-size image): Cocoa pulp is a high-quality by-product of cocoa fruits. The development of novel products using the pulp can increase the sustainability of cocoa farming. The fermentation of cocoa pulp via basidiomycetes shows great potential for the biotechnological formation of highly attractive beverages. This study shows the development of a novel fermented beverage and highlights the creation of a unique aroma profile. The formation of fruity–tropical notes such as passion fruit, peach, mango, and coconut by the fungus Laetiporus persicinus has not been described before. While the beverage has already achieved a high level of acceptance among testers, the field offers further research potential from a scientific point of view, as several unknown sesquiterpenoids with tropical–fruity notes have been detected. View this paper
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10 pages, 1127 KiB  
Article
Horse Manure and Lignocellulosic Biomass Characterization as Methane Production Substrates
by Amar Naji, Sabrina Guérin Rechdaoui, Elise Jabagi, Carlyne Lacroix, Sam Azimi and Vincent Rocher
Fermentation 2023, 9(6), 580; https://doi.org/10.3390/fermentation9060580 - 19 Jun 2023
Cited by 3 | Viewed by 1378
Abstract
This paper aimed to study the value of horse manure through anaerobic digestion. The study involved characterization of different components of horse waste and the evaluation of their biochemical composition, physicochemical characterization and the influence of the composition of horse waste on biochemical [...] Read more.
This paper aimed to study the value of horse manure through anaerobic digestion. The study involved characterization of different components of horse waste and the evaluation of their biochemical composition, physicochemical characterization and the influence of the composition of horse waste on biochemical methane potential. More specifically, two bedding mixtures were studied: the first one was composed of wheat straw (WS), wood chips (WC) and horse manure (HM) with a volumetric composition of 85%, 14% and 1%, respectively; and the second one was a mixture of WS and HM with a volumetric composition of 99% and 1%, respectively. The analysis was carried out on the two bedding mixtures and on each substrate separately with 406 samples from May 2017 to October 2019. Biochemical methane potential tests conducted on these samples showed that the composition and structure of the substrate influenced the BMP. WS had the highest mono-digestion methane production with 176.1 NmL·gVS−1. The second bedding mixture (99% WS, 1% HM) showed a production of 189.4 NmL·gVS−1 compared to 127 NmL·gVS−1 by bedding mixture 1 (85% WS, 14% WC, 1% HM). The difference was due to a dilution effect on methane production caused by the presence of WC rich in lignin. Full article
(This article belongs to the Section Industrial Fermentation)
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19 pages, 4454 KiB  
Article
Aspergillus sclerotiorum Whole-Cell Biocatalysis: A Sustainable Approach to Produce 3-Hydroxy-phenazine 1-Carboxylic Acid from Phenazine 1-Carboxylic Acid
by Malik Jan, Sheng-Jie Yue, Ru-Xiang Deng, Yan-Fang Nie, Hong-Yan Zhang, Xiang-Rui Hao, Wei Wang, Hong-Bo Hu and Xue-Hong Zhang
Fermentation 2023, 9(6), 579; https://doi.org/10.3390/fermentation9060579 - 19 Jun 2023
Viewed by 1267
Abstract
In green chemistry, filamentous fungi are regarded as a kind of robust microorganism for the biotransformation of natural products. Nonetheless, the screening of microorganisms is crucial for the effective biotransformation of natural products, such as phenazine compounds. The precursor metabolite of most phenazine [...] Read more.
In green chemistry, filamentous fungi are regarded as a kind of robust microorganism for the biotransformation of natural products. Nonetheless, the screening of microorganisms is crucial for the effective biotransformation of natural products, such as phenazine compounds. The precursor metabolite of most phenazine derivatives in Pseudomonas spp. is phenazine-1-carboxylic acid (PCA), the key constituent of shenqinmycin, widely used to control rice sheath blight in southern China. In this study, a new fungus strain Aspergillus sclerotiorum was isolated, which can efficiently convert PCA into 3-hydroxy-phenazine 1-carboxylic acid (3-OH-PCA). Moreover, an effective whole cells biotransformation system was designed by screening optimal reaction conditions and carbon sources. Hence, Aspergillus sclerotiorum exhibited desirable adaptation by the consumption of different carbon sources and maximum whole-cell biomass (10.6 g/L DCW) was obtained as a biocatalyst from glucose. Optimal conditions for whole-cell biocatalysis of PCA were evaluated, including a PCA concentration of 1120 mg/L, a pH of 7.0, a temperature of 25 °C, a rotation rate of 200 rpm, and dry cell weight of 15 g/L for 60 h; thus, 1060 mg/L of 3-OH-PCA was obtained and the conversion efficiency of PCA was 94%. Hence, the results of the repeated batch mood revealed that the biotransformation efficiency of fungus pellets reduced with each subsequent cycle, but remained stable in all five cycles with the provision of a glucose supplement. These findings present the prospect of using filamentous fungi for the whole-cell biocatalysis of phenazine in enormous amounts and the efficient production of 3-OH-PCA. Moreover, these results laid the foundation for further research to disclose the genetic-based mechanism of the strain responsible for PCA biotransformation. Full article
(This article belongs to the Section Industrial Fermentation)
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14 pages, 2350 KiB  
Article
Development of Blood Sugar Regulatory Products from Momordica cochininensis via Probiotic Fermentation
by Po-Hua Wu, Huei-Rong Guo, Yi-An Liu, Chien-Hui Wu, Chun-Chen Huang, Jer-An Lin and Chang-Wei Hsieh
Fermentation 2023, 9(6), 578; https://doi.org/10.3390/fermentation9060578 - 18 Jun 2023
Cited by 3 | Viewed by 1642
Abstract
Type II diabetes is the most important health issue in the whole world. Besides the use of prescribed drugs to control blood glucose level, recently, the development of health supplements is being actively explored. Owing to its high nutritional value, Momordica cochinchinensis Spreng. [...] Read more.
Type II diabetes is the most important health issue in the whole world. Besides the use of prescribed drugs to control blood glucose level, recently, the development of health supplements is being actively explored. Owing to its high nutritional value, Momordica cochinchinensis Spreng. (Gac) is potentially a good source for developing this supplement. In recent years, the aril of Gac has been utilized as a substrate for developing various forms of supplements, but the pulp has been neglected as a byproduct. However, the pulp contains lots of phytochemicals that could provide health benefits, and the investigation using lactobacilli to ferment the pulp juices to lower blood glucose is not yet to be explored. Therefore, we set out to investigate the potential to develop the pulp-based juices for controlling blood glucose level by selecting an optimal strain of lactobacillus to ferment the pulp juice and measuring the inhibitory action of the fermented juice on α-glucosidase. This enzyme is crucial for controlling postprandial glucose absorbed into the bloodstream because it is the enzyme that hydrolyzes the carbohydrates to release glucose. First, we have successfully isolated a strain of lactobacillus which was capable of fermenting the pulp to produce α-glucosidase-inhibitory activity. Through a 16S rRNA sequence, this lactobacillus was named Lactiplantibacillus plantarum GBI 001. The optimal conditions for its growth in commercial culture medium were found to be 35 °C for 16 h to produce the highest α-glucosidase activity (72.03%). The optimal conditions for the strain to grow in Gac pulp juice were: 20% pulp juices as substrate with an initial pH adjusted to 4.0, growing at 35 °C for 16 h. Under these conditions, the fermented juice exhibited α-glucosidase activity of 24.36%, which is a 2.17-fold increase over the control group (11.23%). From its increase in α-glucosidase potency, using L. plantarum GBI 001 to ferment the pulp juices of Gac as soft drinks has great potential to develop a helpful drink as a food supplement to control postprandial blood glucose in patients with diabetes. Full article
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16 pages, 1975 KiB  
Article
The Application of Moringa oleifera Leaf Meal and Its Fermentation Products in the Diet of Megalobrama amblycephala Juveniles
by Wenqiang Jiang, Linjie Qian, Yongfeng Zhao, Yan Lin, Yang Yang, Huaishun Shen, Xianping Ge and Linghong Miao
Fermentation 2023, 9(6), 577; https://doi.org/10.3390/fermentation9060577 - 18 Jun 2023
Cited by 1 | Viewed by 1748
Abstract
This study assessed the potential applicability of Moringa oleifera leaf meal (MO) and fermented Moringa oleifera leaf meal (FMO) as feed supplements for aquatic animals. Five experimental diets, including the basal diet (control), 2.2% and 4.4% MO-supplemented diets (MO2 and MO4), and 2.2% [...] Read more.
This study assessed the potential applicability of Moringa oleifera leaf meal (MO) and fermented Moringa oleifera leaf meal (FMO) as feed supplements for aquatic animals. Five experimental diets, including the basal diet (control), 2.2% and 4.4% MO-supplemented diets (MO2 and MO4), and 2.2% and 4.4% FMO-supplemented diets (FMO2 and FMO4), were prepared for feeding Megalobrama amblycephala juveniles. After the eight-week feeding trial, the growth performance, muscle nutritional composition, plasma and hepatic biochemistry indicators were measured. The results demonstrated that MO and FMO had no detrimental effects on the growth performance of M. amblycephala juveniles. The muscle crude protein, crude lipid, and total free amino acids contents were significantly enhanced in the FMO4 group (p < 0.05). The liver acetyl-CoA carboxylase α mRNA level was significantly increased and the lipoprotein lipase mRNA level was markedly reduced in the FMO4 group (p < 0.05). Therefore, the FMO4 group exhibited a significant increase in plasma low-density lipoprotein cholesterol and triglyceride levels (p < 0.05). Compared to the control group, total superoxide dismutase and catalase activities were significantly increased in the FMO4 group (p < 0.05). The FMO2 and FMO4 groups exhibited an anti-inflammatory response by inhibiting the expression levels of toll-like receptor 4, nuclear factor-kappa B, and tumor protein P53 mRNA (p < 0.05). In conclusion, the 4.4% FMO treatment increased muscle crude protein content, enhanced lipogenesis, and improved the hepatic antioxidant abilities of M. amblycephala juveniles, while 2.2% FMO and 4.4% FMO improved the liver anti-inflammatory capacities. Full article
(This article belongs to the Special Issue Feed Fermentation: Nutrition and Metabolism)
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18 pages, 2535 KiB  
Article
Exploration of Natural Product Repository by Combined Genomics and Metabolomics Profiling of Mangrove-Derived Streptomyces murinus THV12 Strain
by Vineetha Das, Niladri Sekhar Chatterjee, Prinetha Uruparambil Pushpakaran, Kuttanappilly V. Lalitha and Toms C. Joseph
Fermentation 2023, 9(6), 576; https://doi.org/10.3390/fermentation9060576 - 18 Jun 2023
Viewed by 1869
Abstract
Streptomyces, one of the largest genera belonging to the phylum Actinobacteria, contribute to more than 60% of the clinically relevant antibiotics. The present study outlined the genomics and the metabolomics of a mangrove-derived Streptomyces murinus THV12 strain. The Illumina Hiseq 2500 platform-based [...] Read more.
Streptomyces, one of the largest genera belonging to the phylum Actinobacteria, contribute to more than 60% of the clinically relevant antibiotics. The present study outlined the genomics and the metabolomics of a mangrove-derived Streptomyces murinus THV12 strain. The Illumina Hiseq 2500 platform-based whole-genome sequencing of the Streptomyces strain generated a consensus sequence of 8,363,247 bp with 107 contigs and 7345 protein-coding genes, which shared significant homology with genes from Streptomyces murinus. The detection of secondary metabolite biosynthetic gene clusters (smBGCs) in the genome performed using the pipeline antiSMASH v6.1.1 revealed that the strain harbored 47 secondary metabolite clusters, which represented 17.9% of the 8.3 Mb genome. The smBGCs belonged to the metabolite categories: PKS, NRPS, ectoine, lassopeptides, lantipeptides, melanin, siderophores, terpenes and other putative products. The strain showed broad-spectrum antimicrobial activity with a inhibition zone of 30 mm against Gram-positive bacteria and Candida albicans. The secondary metabolite profiling of the crude extracts from the fermentation broth of THV12 was performed with the HPLC system coupled with an Orbitrap Exploris120 high-resolution mass spectrometer. As revealed by in silico analysis, compounds such as actinomycin D, pentamycin, desferrioxamine E and cinnabaramide A were detected with MS/MS analysis. Apart from this, compounds belonging to different chemical scaffolds, such as cyclic and linear peptides, bacterial alkaloids, linear polyketides and terpenoids, were also present in the fermentation broth of the strain when cultivated under the OSMAC (One Strain Many Compounds) approach. Thus, the combined strategy of genome mining and metabolomics of the mangrove-derived strain aided in exploring the chemical diversity of BGCs and new chemical entities, which can contribute to drug leads. Full article
(This article belongs to the Special Issue New Research in Production of Antimicrobial Compounds by Fermentation)
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14 pages, 3920 KiB  
Article
Insights into Proteomics Reveal Mechanisms of Ethanol-Enhanced Bacterial Cellulose Biosynthesis by Komagataeibacter nataicola
by Shuangwen Fei, Xuan Yang, Wentao Xu, Jiachao Zhang, Jun Li, Huamei Chen, Xue Lin, Sixin Liu and Congfa Li
Fermentation 2023, 9(6), 575; https://doi.org/10.3390/fermentation9060575 - 17 Jun 2023
Cited by 2 | Viewed by 1410
Abstract
Nata de coco, known as bacterial cellulose (BC), has been given much attention in the food industry and biomaterial areas due to its specific properties such as low calorie content, high content of fiber, high purity and high biocompatibility. Komagataeibacter spp. are indispensable [...] Read more.
Nata de coco, known as bacterial cellulose (BC), has been given much attention in the food industry and biomaterial areas due to its specific properties such as low calorie content, high content of fiber, high purity and high biocompatibility. Komagataeibacter spp. are indispensable microorganisms for BC production due to their highly efficient production. Here, proteomics was applied to investigate the metabolism regulation mechanisms of BC yield improvements in K. nataicola Y19 by 48 ± 3% after ethanol supplementation. The results evidenced that differentially expressed proteins involved in the BC biosynthesis system, glycolytic pathway, TCA cycle and oxidative phosphorylation process were up-regulated. The proteins accelerated the BC biosynthesis by providing more energy and via intermediate metabolites. Furthermore, the elongation factor Tu, chaperone DnaK and translocase subunit SecB may be involved in the BC synthesis procedure by regulating electron transfer, hydrolysis of ATP and protein transformation. Moreover, the ethanol-enhanced BC biosynthesis may be associated with the decreased expression of endoglucanase. This research elucidates the proteomics mechanism of higher BC production based on ethanol addition, providing references for nata de coco production efficiency and the synthetic regulation of bacterial cellulose in the future. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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14 pages, 1369 KiB  
Article
Exploiting Cheese Whey for Efficient Selection of Polyhydroxyalkanoates-Storing Bacteria
by Borja Lagoa-Costa, Christian Kennes and María C. Veiga
Fermentation 2023, 9(6), 574; https://doi.org/10.3390/fermentation9060574 - 17 Jun 2023
Viewed by 815
Abstract
Agroindustrial by-products hold an enormous potential to be bioconverted into high-value-added products such as polyhydroxyalkanoates (PHA), a cost-effective alternative to conventional plastics. In this study, cheese whey, a highly abundant side stream of the cheese making process, was explored as a feasible substrate [...] Read more.
Agroindustrial by-products hold an enormous potential to be bioconverted into high-value-added products such as polyhydroxyalkanoates (PHA), a cost-effective alternative to conventional plastics. In this study, cheese whey, a highly abundant side stream of the cheese making process, was explored as a feasible substrate for the selection of a mixed culture highly enriched in PHA-storing bacteria using a sequencing batch reactor under an aerobic dynamic feeding regime. For that, the absence/presence of thiourea, magnesium and iron, as well as the application of two different organic loading rates (OLR), i.e., 60 and 80 CmM d−1, were tested. The results showed an improved culture selection when thiourea, magnesium and iron were added to the culture medium as well as when the highest OLR was applied. Under these conditions, the biomass achieved a maximum PHA storage of 54% and a PHA production rate of 4.81 Cmmol-PHA L−1 h−1. Additionally, the study of the microbial community showed that during this period of maximum productivity, the biomass was enriched in Azoarcus and Amaricoccus bacterial species. Conclusively, cheese whey can be considered a good feedstock to efficiently select a mixed culture with high potential to accumulate PHA and a good way to give this by-product added value. Full article
(This article belongs to the Special Issue Microbial Production of Polyhydroxyalkanoates (PHAs))
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15 pages, 1134 KiB  
Article
Enhancing Succinic Acid Production by Sequential Adaptation of Selected Basfia succiniciproducens Strains to Arundo donax Hydrolysate
by Alessandro Robertiello, Ida Romano, Valeria Ventorino, Vincenza Faraco and Olimpia Pepe
Fermentation 2023, 9(6), 573; https://doi.org/10.3390/fermentation9060573 - 16 Jun 2023
Cited by 1 | Viewed by 1131
Abstract
Promising green technologies that can overcome the challenges associated with the use of fossil fuels require microorganisms that can effectively ferment lignocellulosic hydrolysate for biochemical production with reduced sensitivity to toxic chemicals derived from the pretreatment process. In this study, a sequential adaptation [...] Read more.
Promising green technologies that can overcome the challenges associated with the use of fossil fuels require microorganisms that can effectively ferment lignocellulosic hydrolysate for biochemical production with reduced sensitivity to toxic chemicals derived from the pretreatment process. In this study, a sequential adaptation approach was developed to obtain new bacterial lines from Basfia (B.) succiniciproducens strains, which are adapted to inhibitory compounds of the Arundo (A.) donax hydrolysate or those that accumulate during the fermentation process. The early adaptation stages resulted in newly adapted B. succiniciproducens bacterial lines that can tolerate fermentation end-products such as acetic, lactic, and succinic acids, as well as toxic compounds such as furfural and hydroxymethylfurfural. These adapted bacterial lines were further investigated to assess their ability to produce succinic acid in an MHM medium supplemented with a filtrate of A. donax hydrolysate. Batch growth tests on a small laboratory scale showed that bacterial lines 2E and 4D produced 5.80 ± 0.56 g L−1 and 5.81 ± 0.39 g L−1 of succinic acid, respectively, after 24 h of fermentation. Based also on its growth rate, the adapted bacterial line B. succiniciproducens 4D was selected for tests in a lab-scale fermenter, where it was able to synthesize up to 17.24 ± 0.39 g L−1 of succinate (corresponding to YSA/gluc 0.96 ± 0.02 g g−1 and to YSA/(G + X) 0.48 ± 0.01 g g−1) from MHM medium added with A. donax hydrolysate. Experiments showed an increase of ~17% compared to the control strain. The overall results demonstrate the potential of adapted bacterial lines for succinate production from A. donax hydrolysate and the development of improved technologies for bio-based succinic acid production. Full article
(This article belongs to the Special Issue Application of Microbial Fermentation in Organic Matter Production)
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15 pages, 4972 KiB  
Article
Effects of Phenyllactic Acid on Fermentation Parameters, Nitrogen Fractions and Bacterial Community of High-Moisture Stylo Silage
by Chenxi Dong, Ping Liu, Xianliu Wang, Wei Zhang and Liwen He
Fermentation 2023, 9(6), 572; https://doi.org/10.3390/fermentation9060572 - 16 Jun 2023
Cited by 1 | Viewed by 961
Abstract
To investigate the effect of phenyllactic acid (PLA) on the dynamic changes of high-moisture stylo silage, fresh stylo was ensiled with addition of PLA at the levels of 0, 1% and 2% using lab-level silage bags, where samples were collected on days 3, [...] Read more.
To investigate the effect of phenyllactic acid (PLA) on the dynamic changes of high-moisture stylo silage, fresh stylo was ensiled with addition of PLA at the levels of 0, 1% and 2% using lab-level silage bags, where samples were collected on days 3, 7, 14 and 30 of ensiling fermentation to analyze fermentation parameters, nitrogen distribution and bacterial community. The results showed that PLA addition at ensiling led to the increase (p < 0.01) in dry matter content, lactic acid concentration and Flieg’s score of stylo silage as well as the decrease (p < 0.01) in dry matter loss, pH value and coliform bacteria population, with butyric acid only detected in the control group. It also resulted in the increase (p < 0.01) in true protein content and its proportion as well as the decrease (p < 0.01) in ammonia-N content and its proportion, almost with linearly dose effect. Sequencing analysis revealed that PLA addition led to the increase (p < 0.05) in Sobs, Shannon, Chao and Ace of bacterial community in the stylo silage, where the relative abundance of Enterobacter, Clostridium, and Kosakonia was decreased, and that of Lactobacillus, Enterococcus and Pantoea was increased. Furthermore, Kosakonia, Terriglobus, Sphingomonas and Sphingopyxis had an important role in the bacterial interaction network. It is suggested that PLA application at the level of 1–2% could improve silage quality of stylo silage via modifying bacterial community. Full article
(This article belongs to the Special Issue Feed Fermentation: A Technology Using Microorganisms and Additives)
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23 pages, 6802 KiB  
Article
Establishment of Flavonoid Fingerprint of TMR Diet and Optimization Factor Analysis Strategy and In Vitro Fermentation Parameters Based on Spectrum–Effect Relationship
by Xiaobo Zhao, Anran Xiong, Shiqiang Yu, Linwei Wang, Jing Wang, Yuchao Zhao and Linshu Jiang
Fermentation 2023, 9(6), 571; https://doi.org/10.3390/fermentation9060571 - 16 Jun 2023
Viewed by 976
Abstract
Nutricines, the nutritionally active substances in feed, play a vital role in enhancing immune function, antioxidant activity, and feed efficiency in dairy cows. Identifying nutricines in total mixed ration (TMR) provides insights into feed quality and their impact on dairy cow health. However, [...] Read more.
Nutricines, the nutritionally active substances in feed, play a vital role in enhancing immune function, antioxidant activity, and feed efficiency in dairy cows. Identifying nutricines in total mixed ration (TMR) provides insights into feed quality and their impact on dairy cow health. However, due to the structural diversity of nutricines, data mining using multivariate variable models faces challenges in exploring their relationships. To address this, this study established a hierarchical clustering and optimization factor strategy for 13 common flavonoid peaks detected using apparent data and HPLC-DAD. The establishment of the flavonoid fingerprint of TMR diet in dairy cows detected 13 common peaks, five of which were found using standard products: p-coumaric acid, sinapic acid, tricin, and diosmetin. In vitro fermentation results using different TMR samples in substrate fermentation indicated that the dry matter disappearance rate, NH3-N, acetate, propionate, butyrate, isovalerate, and valerate changes varied significantly (p < 0.05). In spectrum–activity relationship studies, P2, P6, P8, P9, P10, and P11 were all considered possible factors causing this effect. In the analysis of optimization factor strategy, the peak spectrum model of four fermentation parameters, i.e., pH, dry matter digestibility, NH3-N, and acetate, was constructed after optimization (p < 0.05), and the data model is listed in the main text. In structure–activity relationship studies, ferulic acid, isoferulic acid, methyl sinapic acid, methyl 4-hydroxycinnamate, and p-hydroxybenzalacetone may serve as candidate references for compound 10 and may play an important role in affecting the digestibility of dry matter in in vitro fermentation. These findings highlight the role of flavonoids in TMR feed as key factors in maintaining dairy cow health and differentiating nutritional value. This study proposes a novel method for future TMR diet formulation and quality evaluation, with potential implications for improving dairy cow health and performance. Further research is needed to validate these findings and elucidate the mechanisms underlying nutricine effects on dairy cow nutrition and health. Full article
(This article belongs to the Section Industrial Fermentation)
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18 pages, 2219 KiB  
Article
Bio-Drying of Municipal Wastewater Sludge: Effects of High Temperature, Low Moisture Content and Volatile Compounds on the Microbial Community
by Vladimir Mironov, Ivan Moldon, Anna Shchelushkina, Vitaly Zhukov and Nataliya Zagustina
Fermentation 2023, 9(6), 570; https://doi.org/10.3390/fermentation9060570 - 16 Jun 2023
Cited by 1 | Viewed by 1367
Abstract
This study examined microbiological processes during the bio-drying of municipal wastewater sludge (WS) from the waste treatment facilities of the Moscow region (Russia). In just 21 days of bio-drying, the moisture content of the mixture of WS and wood chips decreased by 19.7%. [...] Read more.
This study examined microbiological processes during the bio-drying of municipal wastewater sludge (WS) from the waste treatment facilities of the Moscow region (Russia). In just 21 days of bio-drying, the moisture content of the mixture of WS and wood chips decreased by 19.7%. It was found that members of the genus Bacillus were the main organic matter destructors. In the period from 7 to 14 days, the rates of organic matter mineralization and moisture loss were the highest, and bacteria of the genus Bacillus dominated, accounting for 43.5 to 84.6% of the bacterial community with a total number of 1.20 (±0.09) × 106 to 6.70 (±0.44) × 105 gene copies µg−1. The maximum number of Amaricoccus was (15.7% of the total bacterial community) in the middle of bio-drying. There was an active accumulation of nitrate nitrogen due to the oxidation of nitrogen-containing substances during the same period of time. Bacteria of the genera Sphingobacterium, Brevundimonas, Brucella, Achromobacter and fungi of the genus Fusarium dominated in the biofilter, which removed volatile compounds from the waste air by 90%. The obtained results allow to model the further intensification of bio-drying, as well as its efficiency and safety. Full article
(This article belongs to the Special Issue New Insights on Sludge Fermentation)
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19 pages, 5685 KiB  
Article
Increased Flux of Lipid Metabolism Enhances Bioethanol Fermentability and Inhibitor Tolerance of Xylose-Utilizing Zymomonas mobilis
by Junyi Hu, William Wang, Feifei Zhang, Xuequan Jiang, Lida Peng, Yichao Fang and Haoyong Wang
Fermentation 2023, 9(6), 569; https://doi.org/10.3390/fermentation9060569 - 16 Jun 2023
Cited by 1 | Viewed by 1250
Abstract
The microbial production of fuel ethanol is an attractive and sustainable biotechnological approach. This study presents a metabolic engineering strategy of Zymomonas mobilis aimed at coproducing bioethanol and fatty acids. The increased flux of fatty acids stabilizes the cell membrane and thus counteracts [...] Read more.
The microbial production of fuel ethanol is an attractive and sustainable biotechnological approach. This study presents a metabolic engineering strategy of Zymomonas mobilis aimed at coproducing bioethanol and fatty acids. The increased flux of fatty acids stabilizes the cell membrane and thus counteracts the progressively higher ethanol toxicity. In a glucose medium, the highest ethanol titer achieved was 146.7 g/kg of broth, surpassing the wild-type Z. mobilis CP4 and angel yeast by 30% and 45%, respectively. The recombinant strain exhibited a total fatty acid titer of 0.4 g/L from 230 g/L total sugar solution (5 L bioreactor), representing a 12-fold increase compared to the wild-type Z. mobilis CP4. Furthermore, when using a 4:2:1 mixture of glucose: xylose: mannose (w/v), an ethanol concentration of 142.8 g/kg of broth was attained, only 2.66% lower than that of the glucose-only medium. These findings highlight the enormous potential of this genetically engineered strain for the sustainable production of ethanol and fatty acids from lignocellulosic renewable carbon sources. Full article
(This article belongs to the Topic Waste-to-Energy)
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11 pages, 976 KiB  
Article
Maca (Lepidium meyenii): In Vitro Evaluation of Rumen Fermentation and Oxidative Stress
by Alessandro Vastolo, Serena Calabrò, Domenico Carotenuto, Monica Isabella Cutrignelli, Dieu donné Kiatti, Simona Tafuri and Francesca Ciani
Fermentation 2023, 9(6), 568; https://doi.org/10.3390/fermentation9060568 - 15 Jun 2023
Cited by 2 | Viewed by 1231
Abstract
The aim of this study was to investigate the chemical composition of three maca (Lepidium meyenii Walp.) ecotypes (yellow, black, and red) and their in vitro fermentation characteristics and antioxidant effects on cow rumen liquor. The three ecotypes were added to a [...] Read more.
The aim of this study was to investigate the chemical composition of three maca (Lepidium meyenii Walp.) ecotypes (yellow, black, and red) and their in vitro fermentation characteristics and antioxidant effects on cow rumen liquor. The three ecotypes were added to a total mixed ratio (TMR) in different doses (0, 150, and 300 mg/g) and incubated in vitro under anaerobic conditions for 120 h. Methane production was recorded after 24 h of incubation. Antioxidant status and degree of lipid peroxidation were also evaluated after 24 and 120 h of incubation with the fermentation liquor. An analysis of the chemical composition showed high concentrations of non-structural carbohydrates in all maca ecotypes, particularly in the yellow ecotypes. Moreover, despite an increase in gas production, it seems that the TMR supplemented with each maca ecotype, particularly at the highest dose, increases the amount of volatile fatty acids and reduces methane production. Finally, the addition of maca can induce an antioxidant effect. Our findings suggest that the three ecotypes of maca are rich in non-structural carbohydrates which affect the in vitro fermentation kinetics and reduce methane production. Full article
(This article belongs to the Special Issue In Vitro Digestibility and Ruminal Fermentation Profile)
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12 pages, 276 KiB  
Article
In Vitro Rumen Fermentation of Coconut, Sugar Palm, and Durian Peel Silages, Prepared with Selected Additives
by Waroon Khota, Paiwan Panyakaew, Piyawit Kesorn, Pongsatorn Gunun, Rattikan Suwannasing, Thachawech Kimprasit, Premsak Puangploy, Ketinun Kittipongpittaya, Anusorn Cherdthong, Suwit Thip-uten, Pakpoom Sawnongbua and Chatchai Kaewpila
Fermentation 2023, 9(6), 567; https://doi.org/10.3390/fermentation9060567 - 15 Jun 2023
Cited by 2 | Viewed by 1673
Abstract
Understanding the nutritive values of fruit peel residues could expand our feed atlas in sustaining livestock production systems. This study aimed to investigate the effects of lactic acid bacteria (LAB), cellulase enzyme, molasses, and their combinations on the fermentation quality and in vitro [...] Read more.
Understanding the nutritive values of fruit peel residues could expand our feed atlas in sustaining livestock production systems. This study aimed to investigate the effects of lactic acid bacteria (LAB), cellulase enzyme, molasses, and their combinations on the fermentation quality and in vitro digestibility of coconut peel (CCP), sugar palm peel (SPP), and durian peel (DRP) silage. The CCP, SPP, and DRP were ensiled in a small-scale silo without additive (control), and with LAB strain TH14 (TH14), molasses, or Acremonium cellulase (AC) using a small-scale silage preparation technique according to a completely randomized design. All fresh peels had sufficient factors for ensiling such as moisture content (78–83%), water-soluble carbohydrates (WSC, 4.20–4.61% dry matter (DM)), and epiphytic LAB population (104–105 colony-forming units (cfu)/g fresh matter (FM)). However, aerobic bacteria counts were high (107–109 cfu/g FM). The fiber content of these fruit peels was high, with lignin abundances ranging from 9.1–21.8% DM and crude protein was low (2.7–5.4% DM). After ensiling, the pH values of the silage were optimal (≤4.25) and lower (p < 0.01) for SPP silage. The addition of molasses+TH14, molasses+AC, and molasses+TH14+AC has the potential to enhance fermentation characteristics and improve chemical composition. Silages treated with molasses alone improved the in vitro digestibility of tropical fruit peels. The residue of tropical fruits has the potential to be used as an alternative feed source for ruminants. Adding molasses, TH14, and AC during silage preparation could improve its nutritive value and digestibility. Full article
(This article belongs to the Special Issue Feed Fermentation: A Technology Using Microorganisms and Additives)
25 pages, 4104 KiB  
Article
Effects of Yogurt with Carao (Cassia grandis) on Intestinal Barrier Dysfunction, α-glycosidase Activity, Lipase Activity, Hypoglycemic Effect, and Antioxidant Activity
by Ricardo S. Aleman, Jhunior Marcia, Ryan Page, Shirin Kazemzadeh Pournaki, Daniel Martín-Vertedor, Víctor Manrique-Fernández, Ismael Montero-Fernández and Kayanush Aryana
Fermentation 2023, 9(6), 566; https://doi.org/10.3390/fermentation9060566 - 15 Jun 2023
Cited by 6 | Viewed by 1865
Abstract
Cell inflammation disrupts intestinal barrier functions and may cause disorders related to a leaky gut, possibly leading to diabetes. The objective of this study was to determine if carao (Cassia grandis) incorporated into yogurt enhances in vitro intestinal barrier function. To [...] Read more.
Cell inflammation disrupts intestinal barrier functions and may cause disorders related to a leaky gut, possibly leading to diabetes. The objective of this study was to determine if carao (Cassia grandis) incorporated into yogurt enhances in vitro intestinal barrier function. To achieve this goal, Caco-2 cells were used as a model of intestinal barrier permeability. Caco-2 cells were treated with cytokines (interleukin-1β, tumor necrosis factor-α, interferon-γ, and lipopolysaccharide (LPS)) and yogurt with carao yogurt (CY) at different doses (1.3 g/L, 2.65 g/L, and 5.3 g/L). Real-time quantitative polymerase chain and immunofluorescence microscopy were applied to evaluate the expression and localization of tight junction proteins. Functional effects of the formulation of yogurt supplemented with carao were also evaluated in terms of the antioxidant activity, the α-glycosidase activity, and lipase inhibitory properties. In addition, the hypoglycemic potential was validated in vivo in a rat model. Compared to the control yogurt, Caco-2 TEER (transepithelial electrical resistance evaluation) by yogurt with 5.3 g/L of carao was significantly lower (p < 0.05) after 48 h. Yogurt with 5.3 g/L of carao had a considerably lower permeability (p < 0.05) than control yogurt in FD and LY flux. Yogurt with 5.3 g/L of carao enhanced the localization of ZO-1. Carao addition into yogurt increased the flavonoid content, apparent viscosity, lipase inhibition activity, and α-glycosidase activity. The rats fed with the yogurt with 5.3 g/L of carao demonstrated a higher blood glucose modulation. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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18 pages, 3049 KiB  
Article
A Novel Batched Four-Stage–Two-Phase Anaerobic Digestion System to Facilitate Methane Production from Rice Straw and Cow Manure with Low Inoculum/Substrate Ratios
by Zhao Yin, Siqi Zhou, Xingyun Zhang, Xuemei Li, Zeming Wang, Juan Wang, Weixing Cao and Chen Sun
Fermentation 2023, 9(6), 565; https://doi.org/10.3390/fermentation9060565 - 15 Jun 2023
Viewed by 1150
Abstract
In order to improve the performance of methane production from agro-waste, a batched four-stage–two-phase anaerobic digestion (4S2P-AD) system was designed to combine the advantages of both anaerobic co-digestion (co-AD) and two-phase AD. The initial separation of two phases was performed using rice straw [...] Read more.
In order to improve the performance of methane production from agro-waste, a batched four-stage–two-phase anaerobic digestion (4S2P-AD) system was designed to combine the advantages of both anaerobic co-digestion (co-AD) and two-phase AD. The initial separation of two phases was performed using rice straw (RS) as a feedstock in acidogenic phase and cow manure (CM) in methanogenic phase at low inoculum/substrate (I/S) ratios of 0.5 and 0.2 and a high organic loading of 60 g volatile solid (VS)/L. The periodic round-trip reflux of leachate during the 4S2P-AD process facilitated re-inoculation throughout the four stages. The results showed that this round-trip reflux also dispersed toxic ammonia, balanced the carbon/nitrogen ratio, unified the microbial community structure, and led to the selection of Methanosarcina (relative abundance > 80%) as the dominant methanogens. With the abilities to overcome volatile fatty acid accumulation, shorten lag times, improve biodegradability, and foster synergistic effects, it was verified that the 4S2P-AD process can maintain efficient and stable methanogenesis from high-solid lignocellulosic feedstock. The averaged methane production throughout the four stages of 4S2P-AD was 234 mL/g VS. This result is 96% higher than the averaged methane production obtained from the four one-step AD groups using mono-feedstock, and 91% higher than that obtained using co-feedstock. This study provides a scientific reference for the development of new processes of bio-methane production from agro-waste with a high fermentation capacity and stability in the future. Full article
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12 pages, 1603 KiB  
Article
Characterization of Bacterial Diversity in Aguamiel and Two Types of Pulque from the Zacatlán Region, México
by Ana Rosa Huezo-Sánchez, Eva Mariel Ortega-Rodríguez, Beatriz Pérez-Armendáriz and Elie Girgis El-Kassis
Fermentation 2023, 9(6), 564; https://doi.org/10.3390/fermentation9060564 - 15 Jun 2023
Viewed by 1115
Abstract
Pulque is a traditional Mexican fermented beverage associated with numerous health benefits. Over time, there has been considerable interest in studying the bacterial diversity of pulque, and microbial characterization has been carried out using traditional microbiological and molecular methods. Therefore, the objective of [...] Read more.
Pulque is a traditional Mexican fermented beverage associated with numerous health benefits. Over time, there has been considerable interest in studying the bacterial diversity of pulque, and microbial characterization has been carried out using traditional microbiological and molecular methods. Therefore, the objective of this research was to characterize the microbiota of artisanal pulque obtained from the Zacatlán region in Puebla, México, by the means of Illumina sequencing, and to compare it with the microbial diversity of aguamiel (sap before fermentation), commercial pulque (supplemented with additives to increase its yield), and its seed (batch of pulque previously fermented). An analysis of the Shannon index showed medium diversity for both aguamiel and pulque samples (score > 2), while the Chao 1 index exhibited a non-significant difference between them. On the other hand, a principal components analysis confirmed the role of the seed as an essential inoculum to define the microbial diversity of pulque, emphasizing the importance of its preservation as a quality standard during the elaboration process. In addition, results showed that the dominant phyla in artisanal and commercial pulque were Firmicutes and Bacteroidetes. As the fermentation process progressed, it was possible to observe an increase in the population of lactic acid bacteria (LAB) in both types of pulque compared to those detected in aguamiel. Of these, the species Lactobacillus, Leuconostoc, and Lactococcus represented almost 95% of the total LAB. Finally, even though the safety of pulque has been in question due to its non-aseptic manufacturing process, the present study confirmed that less than 1% of its microbiota corresponds to the genera with a pathogenic potential such as γ-proteobacteria (Enterobacter and Hafnia), which decreases as the fermentation process advances. Full article
(This article belongs to the Special Issue Nutrition and Health of Fermented Foods, 2nd Edition)
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17 pages, 3133 KiB  
Article
Effect of the Mixed Inoculation of Lactic Acid Bacteria and Non-Saccharomyces on the Quality and Flavor Enhancement of Fermented Mango Juice
by Qiuping Zhong, Ruixin Chen, Ming Zhang, Wenxue Chen, Haiming Chen and Weijun Chen
Fermentation 2023, 9(6), 563; https://doi.org/10.3390/fermentation9060563 - 14 Jun 2023
Cited by 1 | Viewed by 1169
Abstract
Mango juice (MJ) was co-inoculated with Lactobacillus plantarum + Rhodotorula glutinis or Metschnikowia pulcherrima (LP + RG or LP + MP, respectively) and Lactobacillus casei + Rhodotorula glutinis or Metschnikowia pulcherrima (LC + RG or LC + MP, respectively) to evaluate their effect [...] Read more.
Mango juice (MJ) was co-inoculated with Lactobacillus plantarum + Rhodotorula glutinis or Metschnikowia pulcherrima (LP + RG or LP + MP, respectively) and Lactobacillus casei + Rhodotorula glutinis or Metschnikowia pulcherrima (LC + RG or LC + MP, respectively) to evaluate their effect on the physicochemical characteristics, antioxidant capacity, and aroma compounds of MJ after 72 h of fermentation at 28 °C. Results indicated that among the fermented MJ, that which was fermented with LC + RG yielded the highest content of total acid (15.05 g/L). The pH values of MJ fermented with LC + MP, LC + RG, LP + RG, and LP + MP were 3.36, 3.33, 3.26, and 3.19, respectively, and were lower than that of CK (4.79). The juice fermented with LP + MP culture had the lowest sugar content (73.52 g/L), and those fermented with LP + RG and LP + MP had higher total phenol contents and stronger DPPH radical scavenging activity, ABTS radical scavenging activity, iron-reducing antioxidant capacity, and copper reducing antioxidant capacity than the others. Carotenoids in MJ had varying degrees of degradation after mixed fermentation by using all four combinations. Volatile compounds revealed that the co-fermentation of LP + RG produced increased norisoprenoid aroma compounds. The mixed co-inoculation method is a strategy to contemplate for MJ fermentation, but the modalities of inoculation need further investigation. Success depends on the suitable combination of non-Saccharomyces and lactic acid bacteria and consideration of strain variation. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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12 pages, 1467 KiB  
Article
Sequential Bioprocess with Gluconobacter oxydans and Candida tropicalis for Gluconic Acid and Single-Cell Protein Production from Enzymatic Hydrolysate
by Lu Cheng, Rong Huang, Jiaxun Ying, Yixiu Fu, Xin Zhou and Kankan Jiang
Fermentation 2023, 9(6), 562; https://doi.org/10.3390/fermentation9060562 - 13 Jun 2023
Cited by 3 | Viewed by 1818
Abstract
To meet the growing global demand for gluconic acid as a cement and concrete retarder, inexpensive and abundant lignocellulosic materials are regarded as the most suitable alternatives to starchy materials. However, their enzymatic hydrolysate contains not only glucose but also xylose, which negatively [...] Read more.
To meet the growing global demand for gluconic acid as a cement and concrete retarder, inexpensive and abundant lignocellulosic materials are regarded as the most suitable alternatives to starchy materials. However, their enzymatic hydrolysate contains not only glucose but also xylose, which negatively affects the performance of gluconic acid as a retarder. Notably, glucose is preferentially bio-oxidized into gluconic acid by Gluconobacter oxydans, but gluconic acid cannot be metabolized by Candida tropicalis. Given this, an artificially designed biological cascade process, respectively employing Gluconobacter oxydans and Candida tropicalis, was established to successfully carry out glucose conversion into gluconic acid, and xylose into a single-cell protein, using the enzymatic hydrolysate of corncobs as a feedstock. This sequential fermentation process produced 95.8 g/L gluconic acid and 9.0 g/L single-cell protein from one liter of the enzymatic hydrolysate that initially contained 98.1 g/L of glucose and 25.4 g/L of xylose. The mass-balance calculation showed that approximately 280 grams of gluconic acid and 27 grams of the single-cell protein could be harvested from 1000 grams of the corncob feedstock. The results suggest that the above-mentioned two-step bioconversion method is efficient in utilizing glucose and xylose from lignocellulosic hydrolysates. Full article
(This article belongs to the Section Industrial Fermentation)
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20 pages, 2027 KiB  
Article
Fermentation of Date Pulp Residues Using Saccharomyces cerevisiae and Pichia kudriavzevii—Insights into Biological Activities, Phenolic and Volatile Compounds, Untargeted Metabolomics, and Carbohydrate Analysis Post In Vitro Digestion
by Nadia S. Alkalbani, Muneeba Zubair Alam, Anas Al-Nabulsi, Tareq M. Osaili, Amin Olaimat, Shao-Quan Liu, Afaf Kamal-Eldin and Mutamed Ayyash
Fermentation 2023, 9(6), 561; https://doi.org/10.3390/fermentation9060561 - 12 Jun 2023
Viewed by 1440
Abstract
Utilizing agricultural byproducts, such as date pulp residue (DPR), can contribute significantly towards achieving sustainable food production. This paper aimed to investigate the physicochemical properties of DPR and evaluate the health benefits of nonfermented and fermented DPR samples both pre- and post-digestion (bioaccessible [...] Read more.
Utilizing agricultural byproducts, such as date pulp residue (DPR), can contribute significantly towards achieving sustainable food production. This paper aimed to investigate the physicochemical properties of DPR and evaluate the health benefits of nonfermented and fermented DPR samples both pre- and post-digestion (bioaccessible portions). Additionally, it aimed to analyze the carbohydrates and untargeted metabolites in the bioaccessible portions. Fermentation of DPR by Saccharomyces cerevisiae and Pichia kudriavzevii resulted in an abundance of malic acid (over 2400 mg/100 g) and the identification of 42 volatiles, with different degrees of predominance observed in the samples. Twenty phenolics were determined by UPLC in fermented DPR, with (-)-epicatechin, tyrosol, and gallic acid being the most abundant. Bioaccessibility studies revealed that fermented DPR samples retained at least ~44% of α-glucosidase inhibition and exhibited improved α-amylase inhibition compared to nonfermented and undigested samples. In vitro cytotoxicity assays showed a more potent inhibitory effect of fermented DPR against MCF-7 and Caco2 cell lines (average inhibition of 55% and 74.4% for the two types of fermented samples) compared to nonfermented DPR. The untargeted metabolomics analysis identified C5-branched dibasic acid metabolism as the most prominent pathway, with four metabolites identified. Furthermore, the analysis of bioaccessible carbohydrate metabolites in the fermented DPR using LC-QTOF showed the presence of a group of phytochemicals, including three terpenoid metabolites. Full article
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12 pages, 1242 KiB  
Article
Oral Administration of Animal and Plant Protein Mixture with Lactiplantibacillus plantarum IDCC 3501 Improves Protein Digestibility
by Hyeon Ji Jeon, Hayoung Kim, Minjee Lee, Jinseok Moon, Jungyeon Kim, Jungwoo Yang and Young Hoon Jung
Fermentation 2023, 9(6), 560; https://doi.org/10.3390/fermentation9060560 - 12 Jun 2023
Cited by 1 | Viewed by 1431
Abstract
A combined usage of animal and plant proteins-mixture could aid to solve environmental and social problems arising from the use of animal protein alone, while also improving the taste and texture of plant protein. Protein mixtures could be a better protein source due [...] Read more.
A combined usage of animal and plant proteins-mixture could aid to solve environmental and social problems arising from the use of animal protein alone, while also improving the taste and texture of plant protein. Protein mixtures could be a better protein source due to the high availability of amino acids in the body compared with single proteins. Consuming proteins with probiotics can provide more beneficial health effects by helping to hydrolyze protein and absorb amino acids in the body. In this study, coadministration of an animal and plant protein mixture with a high concentration of probiotics was investigated to increase protein digestibility and amino acids absorbability in a mice model. Lactiplantibacillus plantarum IDCC 3501, which has the maximum ability to hydrolyze a protein mixture, composed of soybean protein and milk protein, was selected, and the changes in mice (C57BL/6J, male, six weeks) were investigated after the coadministration of protein mixture and 5 × 108 or 5 × 109 CFU/mL of L. plantarum for eight weeks. Normal diet, high-protein diet (HPD), and HPD supplementing L. plantarum were separately administered to mice. Food and water consumption of the mice did not differ depending on diet type. Measurements of the serum concentrations of amino acids showed that the absorption of aspartate, glutamate, isoleucine, leucine, valine, and lysine increased when high concentrations of protein and probiotics were administered. Thus, high L. plantarum concentrations could be a protein diet supplementation to improve health by promoting the absorption of amino acids. Full article
(This article belongs to the Special Issue Recent Trends in Probiotics and Gut Microbiome for Human Health)
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12 pages, 1616 KiB  
Article
Transcription Analysis of the Acid Tolerance Mechanism of Pichia kudriavzevii NBRC1279 and NBRC1664
by Hironaga Akita and Akinori Matsushika
Fermentation 2023, 9(6), 559; https://doi.org/10.3390/fermentation9060559 - 12 Jun 2023
Cited by 1 | Viewed by 1159
Abstract
Simultaneous saccharification and fermentation (SSF) has been investigated for the efficient production of ethanol because it has several advantages such as simplifying the manufacturing process, operating easily, and reducing energy input. Previously, using lignocellulosic biomass as source materials, we succeeded in producing ethanol [...] Read more.
Simultaneous saccharification and fermentation (SSF) has been investigated for the efficient production of ethanol because it has several advantages such as simplifying the manufacturing process, operating easily, and reducing energy input. Previously, using lignocellulosic biomass as source materials, we succeeded in producing ethanol by SSF with Pichia kudriavzevii NBRC1279 and NBRC1664. However, various acids that fermentation inhibitors are also produced by the hydrolysis of lignocellulosic biomass, and the extent to which these acids affect the growth and ethanol productivity of the two strains has not yet been investigated. In this study, to better understand the acid tolerance mechanism of the two strains, a spot assay, growth experiment, and transcriptome analysis were carried out using Saccharomyces cerevisiae BY4742 as a control. When the three strains were cultured in SCD medium containing 15 mM formic acid, 35 mM sulfuric acid, 60 mM hydrochloric acid, 100 mM acetic acid, or 550 mM lactic acid, only P. kudriavzevii NBRC1664 could grow well under all conditions, and it showed the fastest growth rates. The transcriptome analysis showed that “MAPK signaling pathway-yeast” was significantly enriched in P. kudriavzevii NBRC1664 cultured with 60 mM hydrochloric acid, and most genes involved in the high osmolarity glycerol (HOG) pathway were up-regulated. Therefore, the up-regulation of the HOG pathway may be important for adapting to acid stress in P. kudriavzevii. Moreover, the log2-transformed fold change value in the expression level of Gpd1 was 1.3-fold higher in P. kudriavzevii NBRC1664 than in P. kudriavzevii NBRC1279, indicating that high Gpd1 expression may be accountable for the higher acid tolerance of P. kudriavzevii NBRC1664. The transcriptome analysis performed in this study provides preliminary knowledge of the molecular mechanism of acid stress tolerance in P. kudriavzevii. Our data may be useful for future studies on methods to improve the tolerance of P. kudriavzevii to acids produced from lignocellulose hydrolysis. Full article
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14 pages, 1540 KiB  
Article
Microbiological, Physicochemical and Sensorial Changes during the Ripening of Sucuk, a Traditional Turkish Dry-Fermented Sausage: Effects of Autochthonous Strains, Sheep Tail Fat and Ripening Rate
by Ahmet Akköse, Şeyma Şişik Oğraş, Mükerrem Kaya and Güzin Kaban
Fermentation 2023, 9(6), 558; https://doi.org/10.3390/fermentation9060558 - 12 Jun 2023
Cited by 6 | Viewed by 1215
Abstract
This study aimed to investigate the effects of autochthonous starter cultures (spontaneous fermentation, Lactiplantibacillus plantarum GM77, Staphylococcus xylosus GM92 or L. plantarum GM77 + S. xylosus GM92) isolated from sucuk (a traditional Turkish dry fermented sausage), the use of sheep tail fat (beef [...] Read more.
This study aimed to investigate the effects of autochthonous starter cultures (spontaneous fermentation, Lactiplantibacillus plantarum GM77, Staphylococcus xylosus GM92 or L. plantarum GM77 + S. xylosus GM92) isolated from sucuk (a traditional Turkish dry fermented sausage), the use of sheep tail fat (beef fat-control, sheep tail fat and beef fat + sheep tail fat) and the ripening rate (slow or fast) on the microbiological, physicochemical and sensorial changes during the ripening of sucuk. L. plantarum GM77 as a monoculture or mixed culture with S. xylosus GM92 exhibited good growth during fermentation and following days of ripening. S. xylosus GM92 remained at the inoculation level of 106 CFU/g. L. plantarum GM77 as a monoculture inhibited the growth of spontaneous Micrococcus/Staphylococcus in both the slow and fast ripening conditions. In the presence of L. plantarum GM77, the pH value decreased under 5.0 after the first three days of fermentation. The fast ripening yielded a lower mean aw and TBARS values compared to the slow ripening. Regarding TBARS value, the lowest mean value was determined in the presence of L. plantarum GM77 + S. xylosus GM92. The use of sheep tail fat caused an increase in TBARS; the highest mean value was determined in sucuk prepared with only sheep tail fat. The groups with L. plantarum GM77 yielded a higher mean L* value, while the highest a* value was determined in the group with L. plantarum GM77 + S. xylosus GM92. In addition, fast ripening caused an increase in the a* value. The L*, a* and b* values were not affected by the use of sheep tail fat. L. plantarum GM77 + S. xylosus GM92 groups demonstrated the best results in terms of general acceptability in both slow and fast ripening. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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16 pages, 3201 KiB  
Article
Syntrophic Growth of Biomaibacter acetigenes Strain SP2 on Lactate and Glycerol
by Sofiya Parshina, Elena Zhuravleva, Anna A. Nikitina, Denis Grouzdev, Nadezhda Kostrikina, Vadim Kevbrin, Andrey Novikov, Dmitry Kopitsyn, Tatyana Kolganova, Roman Baslerov, Alla N. Nozhevnikova and Yuriy Litti
Fermentation 2023, 9(6), 557; https://doi.org/10.3390/fermentation9060557 - 11 Jun 2023
Viewed by 1421
Abstract
A moderately thermophilic Gram-positive chemo-organotrophic bacterium, strain SP2, was isolated by serial dilutions with crotonate and yeast extract as substrates from a butyrate-degrading methanogenic enrichment obtained from thermophilically digested sludge of the Kuryanoskaya wastewater treatment plant (Moscow, Russia). Cells of strain SP2 are [...] Read more.
A moderately thermophilic Gram-positive chemo-organotrophic bacterium, strain SP2, was isolated by serial dilutions with crotonate and yeast extract as substrates from a butyrate-degrading methanogenic enrichment obtained from thermophilically digested sludge of the Kuryanoskaya wastewater treatment plant (Moscow, Russia). Cells of strain SP2 are spore-forming rods, sometimes occurring in short chains. The bacterium is an obligate anaerobe that grows at temperatures from 20 to 70 °C (55–60 °C optimum) within a pH range of 3.5–8 (7.5 optimum) and with NaCl concentrations of up to 2.5%. The strain utilized yeast extract and simple sugars as carbon and energy sources. Thiosulfate was used as an electron acceptor when grown on sucrose, resulting in the formation of hydrogen sulfide and the accumulation of elemental sulfur globules inside the cells. Strain SP2 is phylogenetically related to Biomaibacter acetigenes strain SK-G1T as revealed by comparison with the 16S rRNA gene (99.9% identity) and genome (ANI 99%, dDDH 90%) of both strains. It is interesting that strain SP2 was capable of syntrophic conversion of glycerol and lactate when co-cultivated with hydrogenotrophic methanogen, which was not previously shown for the SK-G1T type of strain. The isolation and in-depth study of new facultatively syntrophic microorganisms is important for wastewater treatment ecotechnologies due to their ability to switch to an alternative source of carbon and energy and therefore greater resistance to changing environmental conditions in bioreactors. Full article
(This article belongs to the Section Industrial Fermentation)
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19 pages, 4091 KiB  
Article
Production and Characterization of Poly(3-hydroxybutyrate) from Halomonas boliviensis LC1 Cultivated in Hydrolysates of Quinoa Stalks
by Diego A. Miranda, Katherine Marín, Ola Sundman, Mattias Hedenström, Jorge Quillaguaman, András Gorzsás, Markus Broström, Markus Carlborg, Jenny Lundqvist, Luis Romero-Soto, Leif J. Jönsson, Cristhian Carrasco and Carlos Martín
Fermentation 2023, 9(6), 556; https://doi.org/10.3390/fermentation9060556 - 10 Jun 2023
Cited by 2 | Viewed by 2701
Abstract
The global production of fossil-based plastics has reached critical levels, and their substitution with bio-based polymers is an urgent requirement. Poly(3-hydroxybutyrate) (PHB) is a biopolymer that can be produced via microbial cultivation, but efficient microorganisms and low-cost substrates are required. Halomonas boliviensis LC1, [...] Read more.
The global production of fossil-based plastics has reached critical levels, and their substitution with bio-based polymers is an urgent requirement. Poly(3-hydroxybutyrate) (PHB) is a biopolymer that can be produced via microbial cultivation, but efficient microorganisms and low-cost substrates are required. Halomonas boliviensis LC1, a moderately halophilic bacterium, is an effective PHB producer, and hydrolysates of the residual stalks of quinoa (Chenopodium quinoa Willd.) can be considered a cheap source of sugars for microbial fermentation processes in quinoa-producing countries. In this study, H. boliviensis LC1 was adapted to a cellulosic hydrolysate of quinoa stalks obtained via acid-catalyzed hydrothermal pretreatment and enzymatic saccharification. The adapted strain was cultivated in hydrolysates and synthetic media, each of them with two different initial concentrations of glucose. Cell growth, glucose consumption, and PHB formation during cultivation were assessed. The cultivation results showed an initial lag in microbial growth and glucose consumption in the quinoa hydrolysates compared to cultivation in synthetic medium, but after 33 h, the values were comparable for all media. Cultivation in hydrolysates with an initial glucose concentration of 15 g/L resulted in a higher glucose consumption rate (0.15 g/(L h) vs. 0.14 g/(L h)) and volumetric productivity of PHB (14.02 mg/(L h) vs. 10.89 mg/(L h)) than cultivation in hydrolysates with 20 g/L as the initial glucose concentration. During most of the cultivation time, the PHB yield on initial glucose was higher for cultivation in synthetic medium than in hydrolysates. The produced PHBs were characterized using advanced analytical techniques, such as high-performance size-exclusion chromatography (HPSEC), Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). HPSEC revealed that the molecular weight of PHB produced in the cellulosic hydrolysate was lower than that of PHB produced in synthetic medium. TGA showed higher thermal stability for PHB produced in synthetic medium than for that produced in the hydrolysate. The results of the other characterization techniques displayed comparable features for both PHB samples. The presented results show the feasibility of producing PHB from quinoa stalks with H. boliviensis. Full article
(This article belongs to the Special Issue Food Wastes: Feedstock for Value-Added Products: 4th Edition)
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13 pages, 1717 KiB  
Article
Optimization of Milbemycin Component Ratio by Coordinating Acyl-Coenzyme A Supply Pathways in Streptomyces bingchenggensis
by Xue Yang, Pinjiao Jin, Zhuoxu Dong, Yanyan Zhang, Wensheng Xiang and Shanshan Li
Fermentation 2023, 9(6), 555; https://doi.org/10.3390/fermentation9060555 - 10 Jun 2023
Viewed by 1020
Abstract
Milbemycins are a group of macrolide pesticides with great potential in the agricultural field owing to their high insecticidal activity and environmental compatibility. Milbemycin A3 and A4 with high bioactivities are the main components of milbemycin-derived products, which require a component ratio A4:A3 [...] Read more.
Milbemycins are a group of macrolide pesticides with great potential in the agricultural field owing to their high insecticidal activity and environmental compatibility. Milbemycin A3 and A4 with high bioactivities are the main components of milbemycin-derived products, which require a component ratio A4:A3 of 2.3- to 4.0-fold. Streptomyces bingchenggensis BC04 is a promising milbemycin producer, whereas the component ratio of its products (A4:A3 of 9.0-fold) could not meet the requirement for industrial production. To address this issue, we reconstructed the precursor biosynthetic pathways to fine tune the supply of different acyl-coenzyme A precursors required for milbemycin biosynthesis. Based on an analysis of the intracellular acyl-coenzyme A precursors, we reconstructed stepwise heterogeneous biosynthetic pathways of extender units for milbemycin biosynthesis. Then, we coordinated the supply of milbemycin biosynthetic starter units with temporal promoters. Thanks to these manipulations, we obtained an engineered strain with 39.5% milbemycin titer improvement to 3417.88 mg/L and a qualified component ratio A4:A3 of 3.3-fold. This work demonstrated that coordinating the precursor supply is a simple and effective approach to optimize the component ratio of A4:A3 in milbemycin fermentation products. Moreover, this strategy might also be useful to construct high-yield strains with optimized component ratios of fermentation products in other Streptomyces. Full article
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3 pages, 172 KiB  
Editorial
Marine-Based Biorefinery: A Path Forward to a Sustainable Future
by Abdelrahman Zaky and Abdelfatah Abomohra
Fermentation 2023, 9(6), 554; https://doi.org/10.3390/fermentation9060554 - 10 Jun 2023
Cited by 1 | Viewed by 1236
Abstract
Biofuels and bio-based products are among the best alternatives to fossil-based fuels and chemicals due to their capacity for net-negative carbon emissions, which is a vital contribution to the global ambition of a net-zero economy [...] Full article
(This article belongs to the Special Issue Marine-Based Biorefinery: A Path Forward to a Sustainable Future)
18 pages, 607 KiB  
Article
Bioconversion Study of Olive Tree Biomass Hemicellulosic Hydrolysates by Candida guilliermondii at Different Scales for Ethanol and Xylitol Production
by Juan Gabriel Puentes, Soledad Mateo, Sebastian Sánchez, Inês C. Roberto and Alberto J. Moya
Fermentation 2023, 9(6), 553; https://doi.org/10.3390/fermentation9060553 - 09 Jun 2023
Cited by 1 | Viewed by 1163
Abstract
Hemicellulosic biomass from olive-tree pruning (OTPB) was used as a raw material in order to produce a hemicellulosic hydrolysate to be fermented with the non-traditional yeast Candida guilliermondii FTI 20037 to obtain ethanol and xylitol. The main objectives of this research were to [...] Read more.
Hemicellulosic biomass from olive-tree pruning (OTPB) was used as a raw material in order to produce a hemicellulosic hydrolysate to be fermented with the non-traditional yeast Candida guilliermondii FTI 20037 to obtain ethanol and xylitol. The main objectives of this research were to study the most relevant kinetic parameters involved in the bioconversion process and the correlation between stirred-tank bioreactor and agitated Erlenmeyer flask fermentation. In a first scale-up (using Erlenmeyer flasks) incubated on a rotary shaker at 200 rpm, fermentation assays were performed to determine the most convenient process conditions and the adaptation of the microorganism to the concentrated OTPB and added nutrients culture medium. The best conditions (2.5 kg m3 of initial yeast cells, pH of 5.5 and 30 °C) were set in a bench bioreactor. A comparative study on ethanol and xylitol production was conducted in two scale scenarios, obtaining different results. In the bioreactor, 100% of D-glucose and partially D-xylose were consumed to produce an ethanol yield of 0.28 kg kg1 and an ethanol volumetric productivity of 0.84 kg dm3 h1 as well as a yield and volumetric productivity in xylitol of 0.37 kg kg1 and 0.26 kg dm3 h1, respectively. The kinetic results allowed increasing the action scale and obtaining more real results than the previous steps to enable mini-plant and industrial scaling. Full article
(This article belongs to the Special Issue Yeast, Biofuels, and Value-Added Products 2.0)
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21 pages, 2638 KiB  
Article
Development of Fermented Kombucha Tea Beverage Enriched with Inulin and B Vitamins
by Yuliya Frolova, Valentina Vorobyeva, Irina Vorobyeva, Varuzhan Sarkisyan, Alexey Malinkin, Vasily Isakov and Alla Kochetkova
Fermentation 2023, 9(6), 552; https://doi.org/10.3390/fermentation9060552 - 08 Jun 2023
Cited by 5 | Viewed by 2403
Abstract
Kombucha is a sweet and sour beverage made by fermenting a liquid base with a symbiotic culture of bacteria and yeast. Different tea substrates, carbohydrate sources, and additional ingredients are used to create beverages with different physical and chemical characteristics. The purpose of [...] Read more.
Kombucha is a sweet and sour beverage made by fermenting a liquid base with a symbiotic culture of bacteria and yeast. Different tea substrates, carbohydrate sources, and additional ingredients are used to create beverages with different physical and chemical characteristics. The purpose of this work was to create a recipe and technology to study the properties of the beverage based on kombucha with a given chemical composition. The content of added functional ingredients (vitamins and inulin) in quantities comparable with reference daily intake was the specified parameter characterizing the distinctive features of the enriched beverages. For fermentation using symbiotic cultures of bacteria and yeast, a black tea infusion sweetened with sucrose was used as a substrate. The changes in the physicochemical characteristics of the fermented tea beverage base were evaluated. The dynamics of changes in pH, acidity, the content of mono- and disaccharides, ethanol, organic acids, polyphenolic compounds, and volatile organic substances were shown. The fermentation conditions were selected (pH up to 3.3 ± 0.3, at T = 25 ± 1 °C, process duration of 14 days) to obtain the beverage base. Strawberry and lime leaves were used as flavor and aroma ingredients, and vitamins with inulin were used as functional ingredients. Since the use of additional ingredients changed the finished beverage’s organoleptic profile and increased its content of organic acids, the final product’s physical–chemical properties, antioxidant activity, and organoleptic indicators were assessed. The content of B vitamins in the beverages ranges from 29 to 44% of RDI, and 100% of RDI for inulin, which allows it to be attributed to the category of enriched products. The DPPH inhibitory activity of the beverages was 82.0 ± 7%, and the ethanol content did not exceed 0.43%. The beverages contained a variety of organic acids: lactic (43.80 ± 4.82 mg/100 mL), acetic (205.00 ± 16.40 mg/100 mL), tartaric (2.00 ± 0.14 mg/100 mL), citric (65.10 ± 5.86 mg/100 mL), and malic (45.50 ± 6.37 mg/100 mL). The technology was developed using pilot equipment to produce fermented kombucha tea enriched with inulin and B vitamins. Full article
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17 pages, 4117 KiB  
Article
Moisture-Induced Effects on Lignocellulosic and Humification Fractions in Aerobically Composted Straw and Manure
by Philip Ghanney, Stephen Yeboah, Dominic Kwadwo Anning, Huizhen Yang, Youling Wang and Huizhen Qiu
Fermentation 2023, 9(6), 551; https://doi.org/10.3390/fermentation9060551 - 08 Jun 2023
Cited by 4 | Viewed by 1493
Abstract
Humic substances affect compost stability and maturation. However, the intricate structure of lignocellulosic materials hinders the biodegradation of cellulose, hemicellulose, and lignin, often promoting the use of synthetic additives which results in microbial inactivation and death. Therefore, this study examined the effects of [...] Read more.
Humic substances affect compost stability and maturation. However, the intricate structure of lignocellulosic materials hinders the biodegradation of cellulose, hemicellulose, and lignin, often promoting the use of synthetic additives which results in microbial inactivation and death. Therefore, this study examined the effects of optimal moisture levels (MC1 = 45%, MC2 = 55%, and MC3 = 65%) on lignocellulosic and humification fractions in aerobically composted straw and manure. The study showed that 65% moisture content was more efficient in decomposing cellulose, hemicellulose, and lignin, with hemicellulose (115.3% w/w ≈ 47.1%) degrading more than cellulose (76.0% w/w ≈ 39.5%) and lignin (39.9% w/w ≈ 25.9%). However, in compost heaps with 45% moisture, the humic acid concentration increased significantly by 12.4% (3.1% w/w) and 17.3% (4.3% w/w) compared with 55% and 65% moisture, respectively. All moisture levels increased the mineralization of humic substances, but the index measured was highest at 65% MC (23.8% w/w) and lowest at 45% MC (18% w/w). In addition, the humification rate showed the trend: 0.083% w/w > 0.087% w/w > 0.100% w/w for MC1, MC2, and MC3, respectively. Overall, the results indicate that an initial moisture content of 65% is aerobically efficient for the conversion of corn straw and cow manure into stable and mature compost. Full article
(This article belongs to the Section Industrial Fermentation)
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