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Fermentation, Volume 8, Issue 12 (December 2022) – 92 articles

Cover Story (view full-size image): When searching for novel natural dyes, fungal pigments bear an untapped potential. Their fruiting bodies have a long history as artisanal dyes, but cultivation is difficult to scale up for industrial use. In this article, the biotechnological production of a yellow-orange colorant produced by submerged fermentation of the edible mushroom Laetiporus sulphureus was examined more closely. Identification of the best strain and media led to a final yield of 1 g L−1 laetiporic acid in a 7 L stirred tank bioreactor. The colorant successfully dyed foods, cosmetics, and textiles. It can potentially replace petrochemically based synthetic dyes and thus support the development of a circular bioeconomy. View this paper
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14 pages, 1104 KiB  
Article
Effect of Formic Acid and Inoculants on Microbial Community and Fermentation Profile of Wilted or Un-Wilted Italian Ryegrass Silages during Ensiling and Aerobic Exposure
by Qifan Ran, Hao Guan, Haiping Li, Wei He, Ruifen Zhu, Li Zhang, Yong Huang, Yuandong Xu and Yan Fan
Fermentation 2022, 8(12), 755; https://doi.org/10.3390/fermentation8120755 - 19 Dec 2022
Cited by 4 | Viewed by 1490
Abstract
Wilted (around 35% DM) or un-wilted (around 35% DM) Italian ryegrass treated with three additives (formic acid, FA; Lactobacillus plantarum, LP; Lactobacillus buchneri, LB) was utilized to evaluate the effects of the dry matter (DM) contents on the microbial community and [...] Read more.
Wilted (around 35% DM) or un-wilted (around 35% DM) Italian ryegrass treated with three additives (formic acid, FA; Lactobacillus plantarum, LP; Lactobacillus buchneri, LB) was utilized to evaluate the effects of the dry matter (DM) contents on the microbial community and fermentation characteristics, which was ensiled for 60 days in a laboratory-scale silo, followed by 3 days of aerobic exposure. Significantly lower pH and higher lactic acid (LA) contents were observed in the LP-treated group ensiled at both DM contents (differences were significant when p < 0.05). The contents of LA, acetic acid (AA), numbers of lactic acid bacteria (LAB) and ammonia nitrogen (NH3-N) in the FA-treated group were significantly lower than those in other treatments (p < 0.05). L. buchneri was the dominant bacteria after 60 days fermentation, while Enterobacteria became prevalent after 3 days of aerobic exposure. L. buchneri was found in the LB-treated group with higher acetic acid. Although the best fermentation quality was observed in the LP-treated silages, the aerobic stability was lowest compared to other groups (p < 0.05). In conclusion, our findings suggest that the DM content of Italian ryegrass affected its epiphytic microbial community and the effectiveness of the different type of additives. Formic acid was more suitable for un-wilted Italian ryegrass silage, L. plantarum had a better effect in wilted Italian ryegrass silage, and L. buchneri prolonged the aerobic stability of Italian ryegrass. DM content and purpose of ensiling should be the key factors for choosing different types of additives for Italian ryegrass silage. Full article
(This article belongs to the Section Industrial Fermentation)
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19 pages, 4169 KiB  
Article
Analysis of the Microbial Community Structure and Volatile Metabolites of JIUYAO in Fangxian, China
by Wendi Zhang, Qing Ren, Zhongchao Wang, Huijie Liu, Mingquan Huang, Jihong Wu and Baoguo Sun
Fermentation 2022, 8(12), 754; https://doi.org/10.3390/fermentation8120754 - 18 Dec 2022
Cited by 2 | Viewed by 1595
Abstract
JIUYAO is an important saccharification starter in the production of huangjiu and is also an important source of flavor. In this study, the microbial community structure of JIUYAO from Fangxian was studied by high-throughput sequencing (HTS) technology for the first time. The volatile [...] Read more.
JIUYAO is an important saccharification starter in the production of huangjiu and is also an important source of flavor. In this study, the microbial community structure of JIUYAO from Fangxian was studied by high-throughput sequencing (HTS) technology for the first time. The volatile flavor compounds of the JIUYAO metabolites were also analyzed by headspace solid-phase microextraction combined with full two-dimensional gas chromatography-mass spectrometry (HS-SPME-GC×GC/MS) for the first time. The results showed that there were 15 dominant bacterial genera, including Weissella, Pediococcus, unclasssified_k_norank_d_Bacteria, Lactobacillus, Leuconostoc, etc. Thirteen species of dominant fungi included Wickerhamomyces, Saccharomycopsis, Rhizopus, etc. The different samples of JIUYAO were similar in their microbial species, but the number of species was significantly different. A total of 191 volatile flavor compounds (VFCs) were detected, among which esters, alcohols, acids, and alkenes were the main flavor compounds, and 21 terpenoids were also detected. In addition, the functional prediction of micro-organisms in JIUYAO revealed that global and overview maps, amino acid metabolism, and carbohydrate metabolism were the dominant categories. Through correlation analysis, 538 potential correlations between the dominant micro-organisms and the different flavor compounds were obtained. This study revealed the interactions between the micro-organisms and the volatile metabolites in JIUYAO, which provided reliable data for the analysis of the microbial community structure of Fangxian JIUYAO and provided theoretical support for the quality evaluation of JIUYAO. Full article
(This article belongs to the Special Issue Perspectives on Microbiota of Fermented Foods)
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11 pages, 926 KiB  
Article
Preliminary Study on Red Wine Aroma: The Volatile Profiles of Six Grape Cultivars in Different Vinification Phases
by Roberta Ascrizzi, Ylenia Pieracci, Bernardo Melai, Pier Luigi Cioni, Patrizio Narri, Guido Flamini and Luisa Pistelli
Fermentation 2022, 8(12), 753; https://doi.org/10.3390/fermentation8120753 - 18 Dec 2022
Viewed by 1291
Abstract
Consumers’ appreciation of wines is mainly driven by their aroma, which is the most important organoleptic characteristic and key attribute. The volatile bouquet derives from the grape berries and from the processing phases of vinification. In the present study, the volatile emission of [...] Read more.
Consumers’ appreciation of wines is mainly driven by their aroma, which is the most important organoleptic characteristic and key attribute. The volatile bouquet derives from the grape berries and from the processing phases of vinification. In the present study, the volatile emission of six grapevine cultivars has been analysed through four phases of vinification: the headspaces of crushed grapes, fermented must, new wine (2 months old), and wine (7 months old) have been sampled and analysed. This showed the evolution of the volatile compounds based on the chemical and mechanical processes involved in the specific vinification phase. Chemometric tools (hierarchical cluster and principal component analyses) have revealed that samples gather in statistical groups based on the vinification phase they belong to, though they maintain an aroma composition that is typical of the grape berry of origin. Full article
(This article belongs to the Special Issue Flavor and Aroma in the Fermented Food)
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14 pages, 625 KiB  
Article
Evaluation of Rye Bran Enzymatic Hydrolysate Effect on Gene Expression and Bacteriocinogenic Activity of Lactic Acid Bacteria
by Julia M. Epishkina, Maria V. Romanova, Marina A. Chalenko, Natalya Yu. Khromova, Boris A. Karetkin, Andrey V. Beloded, Maria A. Kornienko, Yulia M. Averina, Irina V. Shakir and Victor I. Panfilov
Fermentation 2022, 8(12), 752; https://doi.org/10.3390/fermentation8120752 - 17 Dec 2022
Viewed by 1545
Abstract
Lactic acid bacteria (LAB) bacteriocins can be considered as a bio-preservatives and an alternative to antibiotics, but the high manufacturing costs limit their commercial application. The screening of LAB strains for bacteriocinogenic activity was carried out and the effect of rye bran enzymatic [...] Read more.
Lactic acid bacteria (LAB) bacteriocins can be considered as a bio-preservatives and an alternative to antibiotics, but the high manufacturing costs limit their commercial application. The screening of LAB strains for bacteriocinogenic activity was carried out and the effect of rye bran enzymatic hydrolysate (RBEH) on gene expression and bacteriocin production was evaluated. qPCR and RT-PCR was applied for bacteriocin gene detection and their expression quantification. The agar diffusion technique with the test strains of Bacillus spp., Staphylococcus spp. and Salmonella enterica was performed for antimicrobial activity assessment of LAB cultivated in MRS broth and RBEH (processed with proteases and cellulases). The genes of different bacteriocins were revealed for thirteen out of eighteen LAB strains, while the antimicrobial activity was detected only for four of them. The strains of Lactobacillus paracasei VKPM B-11657 and L. salivarius VKPM B-2214 with unnamed class IIb bacteriocin gene demonstrated the widest spectrum of activity. The growth patterns and bacteriocin gene expression differed between both strains and media. The activity of cell-free supernatants after cultivation in RBEH was slightly lower. However, the test strain of S. epidermidis was inhibited by L. paracasei cultivated in RBEH but not in MRS. Thus, rye bran can be applied as a sole source of nutrients for LAB fermentation and bacteriocin production. Full article
(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food)
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2 pages, 186 KiB  
Editorial
The Rendering of Traditional Fermented Foods in Human Diet: Distribution of Health Benefits and Nutritional Benefits
by Stavros Plessas
Fermentation 2022, 8(12), 751; https://doi.org/10.3390/fermentation8120751 - 16 Dec 2022
Cited by 2 | Viewed by 1271
Abstract
Most fermented foods are based on the cultural preferences of different geographical areas and the heterogeneity of traditions from where they are produced. For instance, many consumers in Asian countries prefer fermented seafood, while consumers in Europe prefer fermented cereal and dairy food [...] Read more.
Most fermented foods are based on the cultural preferences of different geographical areas and the heterogeneity of traditions from where they are produced. For instance, many consumers in Asian countries prefer fermented seafood, while consumers in Europe prefer fermented cereal and dairy food products. Even though the food industry has developed various novel techniques in order to produce novel foods (genetic modification, nanotechnology and other processing techniques), traditional foods still represent a significant proportion of the food industry, which has recently appeared to develop further. In addition, the progress in various developed analytical techniques has revealed new knowledge that documents and corroborates certain benefits of traditional foods, mostly regarding their nutritional and health benefits. In this context, the main target of this Special Issue is to deliver new data on how traditional foods exhibit their health-promoting properties and ameliorate the nutritional value of fermented food systems. In addition, the involvement of wild starter culture in the production of traditional foods is a subject area that must be highlighted. Full article
12 pages, 3453 KiB  
Article
Identification and Transcriptional Profiling of SNARE Family in Monascus ruber M7 Reveal Likely Roles in Secondary Metabolism
by Chenchen Meng, Youxiang Zhou, Jiao Liu and Fusheng Chen
Fermentation 2022, 8(12), 750; https://doi.org/10.3390/fermentation8120750 - 16 Dec 2022
Viewed by 1287
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are the core components that mediate vesicle fusion, and they play an important role in secondary metabolism of filamentous fungi. However, in Monascus spp., one of the traditional medicinal and edible filamentous fungi, the members and [...] Read more.
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are the core components that mediate vesicle fusion, and they play an important role in secondary metabolism of filamentous fungi. However, in Monascus spp., one of the traditional medicinal and edible filamentous fungi, the members and function of SNAREs remain unknown. Here, twenty SNAREs in M. ruber M7 were systematically identified based on the gene structure, amino acid structure and phylogenetic analysis and were classified into four subfamilies. We also compared the expression profiles of twenty MrSNAREs in M. ruber M7 and its deletion mutants, ΔmrpigA and ΔpksCT, which could not produce Monascus pigment and citrinin, respectively. The results indicated that these MrSNAREs showed distinct expression patterns in the three strains. Compared to M. ruber M7, the expression levels of Mrtlg2, Mrbet1, Mrgos1 and Mrsec22 remained higher in ΔmrpigA but lower in ΔpksCT, which could be reason to consider them as potential candidate genes involved in secondary metabolism for further functional characterization. Further, the significant upregulation of Mrpep12 and Mrvtil in ΔpksCT is worthy of attention for further research. Our results provide systematic identification and expression profiling of the SNARE family in Monascus and imply that the functions of MrSNAREs are specific to different secondary metabolic processes. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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7 pages, 439 KiB  
Article
Effect of Sodium Hydroxide Treatment on Chemical Composition and Feed Value of Common Reed (Phragmites australis) Straw
by Ahmet Uzatici, Onder Canbolat and Adem Kamalak
Fermentation 2022, 8(12), 749; https://doi.org/10.3390/fermentation8120749 - 16 Dec 2022
Cited by 2 | Viewed by 1922
Abstract
This research was undertaken with the aim of determining the effect of sodium hydroxide (NaOH) treatment on the chemical composition, in vitro gas production, neutral detergent fiber digestibility (NDFD) and true dry matter digestibility (TDMD), dry matter intake (DMI), and relative feed value [...] Read more.
This research was undertaken with the aim of determining the effect of sodium hydroxide (NaOH) treatment on the chemical composition, in vitro gas production, neutral detergent fiber digestibility (NDFD) and true dry matter digestibility (TDMD), dry matter intake (DMI), and relative feed value (RFV) of common reed (Phragmites australis) straw. Reed straw was treated with 0% (control), 1%, 2%, and 3% NaOH and stored in 1.5-L glass jars in triplicate for 21 days. NaOH treatment had a significant effect on the chemical composition, in vitro gas production, NDFD and TDMD, DMI, and RFV of the reed straw. While it decreased the cell wall content of the reed straw, it significantly increased the NDFD, TDMD, DMI, and RFV. The neutral detergent fiber content of the reed straw decreased with NaOH treatment in a dose-dependent manner and ranged from 56.03% to 65.05%, whereas the NDFD increased and ranged from 53.10% to 59.99%. Metabolizable energy, organic matter digestibility, and TDMD values were improved, ranging from 9.15 to 10.19 MJ/kg DM, 58.46% to 65.05%, and 55.29% to 62.33%, respectively. The estimated RFV and DMI also improved, ranging from 84.70% to 95.58% and from 1.87% to 2.14% of body weight, respectively. The most effective treatment dose of NaOH was 3%. Therefore, it can be suggested that NaOH treatment has the potential to improve the nutritive value of reed straw. However, before large applications, further in vivo investigations are required to determine the effects of NaOH treatment on the feed intake and production of ruminant animals. Full article
(This article belongs to the Special Issue In Vitro Fermentation, 2nd Edition)
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14 pages, 926 KiB  
Article
Use of Kombucha SCOBY and Commercial Yeast as Inoculum for the Elaboration of Novel Beer
by Mariana Muniz da Silva, Angélica Cristina de Souza, Emanuel Roberto Faria, Gustavo Molina, Nathalia de Andrade Neves, Harriman Aley Morais, Disney Ribeiro Dias, Rosane Freitas Schwan and Cíntia Lacerda Ramos
Fermentation 2022, 8(12), 748; https://doi.org/10.3390/fermentation8120748 - 16 Dec 2022
Cited by 4 | Viewed by 2927
Abstract
Kombucha is a beverage obtained from fermentation of Camellia sinensis tea using a symbiotic culture of bacteria and yeast (SCOBY). This association of bacteria and yeasts can be an interesting source of microorganisms for developing fermented beverages, including beer. The objective of this [...] Read more.
Kombucha is a beverage obtained from fermentation of Camellia sinensis tea using a symbiotic culture of bacteria and yeast (SCOBY). This association of bacteria and yeasts can be an interesting source of microorganisms for developing fermented beverages, including beer. The objective of this study was to evaluate kombucha SCOBY and commercial brewing yeast as a starter culture for the elaboration of beer. Three assays were performed to develop the beverage (C = control, KL = kombucha + yeast, K = kombucha). The pH, density, carbohydrates, organic acids and ethanol were evaluated during fermentation. Microbial counts (yeasts and mesophilic bacteria) and volatile compounds were recorded at the initial and final fermentation times. The content of total phenolic compounds, antioxidant capacity, color and bitterness (IBU) of the beers were determined. The results showed that kombucha-fermented wort produces a beer with differentiated characteristics. Increased lactic acid (0.73 g/L) and low alcohol content (1.3%) were observed in the K assay. Further, desired volatile compounds, such as ethyl octanoate, phenethyl acetate and 2-phenylethanol, were also found in this beer. The combination of kombucha and commercial yeast for beer production showed carbohydrate consumption and contents of organic acids similar to those of control beer, producing beers with an alcohol content of 5.9%. From the results, it was possible to observe a tendency for the content of total phenolic compounds (37.57, 33.00 and 31.64 mg/100 mL for K, KY and C assays, respectively) to increase when the wort was inoculated with kombucha. There was no difference in the antioxidant activity of the produced beers. All produced beers showed a yellowish color and a bitterness value (IBU) of 27%. The present study showed that adding kombucha as a starter culture produced beer with differentiated properties, such as high antioxidant activity, low alcohol content and sour characteristics. Full article
(This article belongs to the Special Issue Research Advances in Fermented Beverages)
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16 pages, 3679 KiB  
Article
Lentilactobacillus buchneri Preactivation Affects the Mitigation of Methane Emission in Corn Silage Treated with or without Urea
by Caner Bağcık, Fisun Koç, Kadir Erten, Selim Esen, Valiollah Palangi and Maximilian Lackner
Fermentation 2022, 8(12), 747; https://doi.org/10.3390/fermentation8120747 - 15 Dec 2022
Cited by 6 | Viewed by 1460
Abstract
The aim of this study was to investigate the effect of different forms of Lentilactobacillus buchneri on the in vitro methane production, fermentation characteristics, nutritional quality, and aerobic stability of corn silage treated with or without urea. The following treatments were applied prior [...] Read more.
The aim of this study was to investigate the effect of different forms of Lentilactobacillus buchneri on the in vitro methane production, fermentation characteristics, nutritional quality, and aerobic stability of corn silage treated with or without urea. The following treatments were applied prior to ensiling: (1) no urea treatment and LB; (2) no urea treatment+freeze dried LB; (3) no urea treatment+preactivated LB; (4) with urea treatment+no LB; (5) with urea treatment+freeze dried LB; (6) with urea treatment+preactivated. LB was applied at a rate of 3 × 108 cfu/kg on a fresh basis, while urea was applied at a rate of 1% on the basis of dry matter. Data measured at different time points were analyzed according to a completely randomized design, with a 2 × 3 × 5 factorial arrangement of treatments, while the others were analyzed with a 2 × 3 factorial arrangement. Preactivated LB was more effective than freeze-dried LB in reducing silage pH, ammonia nitrogen, cell-wall components, yeast count, and carbon dioxide production, as well as increasing lactic acid and residual water-soluble carbohydrate and aerobic stability (p < 0.0001). A significant reduction in the methane ratio was observed after 24 h and 48 h incubation with preactivated forms of LB (p < 0.001). The results indicated that preactivated LB combined with urea improved fermentation characteristics, nutritional quality, and aerobic stability and reduced the methane ratio of corn silages. Full article
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24 pages, 3556 KiB  
Article
Characterization of Biofilm Microbiome Formation Developed on Novel 3D-Printed Zeolite Biocarriers during Aerobic and Anaerobic Digestion Processes
by Afroditi G. Chioti, Vasiliki Tsioni, Stefanos Patsatzis, Eirini Filidou, Dimitra Banti, Petros Samaras, Eleni Anna Economou, Eleni Kostopoulou and Themistoklis Sfetsas
Fermentation 2022, 8(12), 746; https://doi.org/10.3390/fermentation8120746 - 15 Dec 2022
Cited by 4 | Viewed by 2142
Abstract
Background: Aerobic or anaerobic digestion is involved in treating agricultural and municipal waste, and the addition of biocarriers has been proven to improve them further. We synthesized novel biocarriers utilizing zeolites and different inorganic binders and compared their efficiency with commercially available biocarriers [...] Read more.
Background: Aerobic or anaerobic digestion is involved in treating agricultural and municipal waste, and the addition of biocarriers has been proven to improve them further. We synthesized novel biocarriers utilizing zeolites and different inorganic binders and compared their efficiency with commercially available biocarriers in aerobic and anaerobic digestion systems. Methods: We examined BMP and several physicochemical parameters to characterize the efficiency of novel biocarriers on both systems. We also determined the SMP and EPS content of synthesized biofilm and measured the adherence and size of the forming biofilm. Finally, we characterized the samples by 16S rRNA sequencing to determine the crucial microbial communities involved. Results: Evaluating BMP results, ZSM-5 zeolite with bentonite binder emerged, whereas ZSM-5 zeolite with halloysite nanotubes binder stood out in the wastewater treatment experiment. Twice the relative frequencies of archaea were found on novel biocarriers after being placed in AD batch reactors, and >50% frequencies of Proteobacteria after being placed in WWT reactors, compared to commercial ones. Conclusions: The newly synthesized biocarriers were not only equally efficient with the commercially available ones, but some were even superior as they greatly enhanced aerobic or anaerobic digestion and showed strong biofilm formation and unique microbiome signatures. Full article
(This article belongs to the Special Issue Energy Converter: Anaerobic Digestion)
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13 pages, 919 KiB  
Review
Wine Minerality and Funkiness: Blending the Two Tales of the Same Story
by Manuel Malfeito-Ferreira
Fermentation 2022, 8(12), 745; https://doi.org/10.3390/fermentation8120745 - 15 Dec 2022
Cited by 1 | Viewed by 1979
Abstract
In wines, minerality is a complex concept with increasing popularity in scientific research and the wine press. The flavour conceptual space of mineral wines comprises sulphur-reduced aromas, such as flint, wet stone or chalk associated with freshness and lingering mouth perceptions. Professionals do [...] Read more.
In wines, minerality is a complex concept with increasing popularity in scientific research and the wine press. The flavour conceptual space of mineral wines comprises sulphur-reduced aromas, such as flint, wet stone or chalk associated with freshness and lingering mouth perceptions. Professionals do not consider the perception of sulphur-reduced flavours as an off-flavour. Indeed, this sort of reduction is a cue for the recognition of minerality under a likely top-down mental process. However, untrained consumers perceive these aromas as unpleasant. This different qualitative assessment hampers the communication between professionals and amateurs. This review aimed to describe the perceptions of minerality by experts and novices to promote their mutual understanding. Funkiness is proposed as a descriptor of mineral wines when tasted by unexperienced consumers. The chemical basis of minerality and winemaking options were explored to understand their implications on sensory perception. Mineral flavours have two main features. The first comprises ephemeral aromas that may be described as funky, given their association with sulphur-reduced molecules. The second is linked to the fresh and vivacious lingering mouthfeel perceptions that remain after the reductive aromas vanish. Consumers recognise this dual perception by demonstrating positive emotional responses of surprise during tasting. Then, the perception of minerality is a question of cognition and not of particularly developed sensory skills. Appropriate tasting approaches encompassing emotional responses and emergent properties (e.g., harmony, depth, persistence, complexity) appear essential to understand the nature of wine minerality and to determine when it may be regarded as a surrogate for fine wine quality. Full article
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14 pages, 2159 KiB  
Article
Valorization of Fourth-Range Wastes: Evaluating Pyrolytic Behavior of Fresh and Digested Wastes
by Elia Judith Martínez, Rubén González, Marcos Ellacuriaga and Xiomar Gómez
Fermentation 2022, 8(12), 744; https://doi.org/10.3390/fermentation8120744 - 15 Dec 2022
Cited by 2 | Viewed by 1338
Abstract
Changes in daily habits and a stressful lifestyle create modifications in consumer preferences and open opportunities to new market products. This is the case of fourth-range products in which the industrial sector generates a waste stream of high quality. Valorization of this type [...] Read more.
Changes in daily habits and a stressful lifestyle create modifications in consumer preferences and open opportunities to new market products. This is the case of fourth-range products in which the industrial sector generates a waste stream of high quality. Valorization of this type of waste as a single stream is desirable to avoid lowering quality with other low-grade materials. Anaerobic digestion of fourth-range wastes was studied under discontinuous and semi-continuous conditions. A high carbon content characterizes the organic material composed of fruit and vegetable wastes. The fast degradation of the substrate indicated no limitations associated with the hydrolysis stage, as observed from kinetic parameters estimated from batch assays. However, the easiness of degradation did not translate into short hydraulic retention times when operating under semi-continuous conditions. Additionally, the insufficient amount of nutrients prevented the development of a well-balanced digestion process. Specific methane production was 325 mL CH4/g VS added at a hydraulic retention time of 30 days. However, solid accumulation was observed at the end of the experiment, indicating that conditions established did not allow for the complete conversion of the organic material. Digestate evaluation using thermal analysis under inert conditions showed a thermal profile evidencing the presence of complex components and a high tendency to char formation. Full article
(This article belongs to the Special Issue Advanced Research in Biomass and Waste Valorization)
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22 pages, 417 KiB  
Review
Traditional Fermented Dairy Products in Southern Mediterranean Countries: From Tradition to Innovation
by Marina Mefleh, Amira M. Galal Darwish, Priti Mudgil, Sajid Maqsood and Fatma Boukid
Fermentation 2022, 8(12), 743; https://doi.org/10.3390/fermentation8120743 - 14 Dec 2022
Cited by 5 | Viewed by 3435
Abstract
Fermented dairy products have been essential elements in the diet of Southern Mediterranean countries for centuries. This review aims to provide an overview of the traditional fermented products in Southern Mediterranean countries, with a focus on fermented dairy products, and to discuss innovative [...] Read more.
Fermented dairy products have been essential elements in the diet of Southern Mediterranean countries for centuries. This review aims to provide an overview of the traditional fermented products in Southern Mediterranean countries, with a focus on fermented dairy products, and to discuss innovative strategies to make improved versions of these traditional products. A large variety of fermented dairy products were reviewed, showing high diversity, depending on the used raw materials, starter cultures, and preparation procedures. Traditionally, dairy products were fermented using spontaneous fermentation, back-slopping, and/or the addition of rennet. Compared with commercial products, traditional products are characterized by peculiar organoleptic features owing to the indigenous microflora. The main limitation of traditional products is preservation as most products were consumed fresh. In addition to drying, brine or oil was used to extend the product shelf life but resulted in high salt/fat products. Several studies suggested alternative ingredients/processing to make revised products with new flavors, improved nutritional quality, and a longer shelf life. There is still plenty of room for more research to obtain a better understanding of the indigenous microflora and on quality improvement and standardization to reach a wider market. Full article
(This article belongs to the Special Issue Dairy Fermentation)
11 pages, 2036 KiB  
Article
Analysis of the Comparative Growth Kinetics of Paenarthrobacter ureafaciens YL1 in the Biodegradation of Sulfonamide Antibiotics Based on Substituent Structures and Substrate Toxicity
by Lan Yu, Yingning Wang, Junjie Xin, Fang Ma and Haijuan Guo
Fermentation 2022, 8(12), 742; https://doi.org/10.3390/fermentation8120742 - 14 Dec 2022
Viewed by 1261
Abstract
The high consumption and emission of sulfonamide antibiotics (SAs) have a considerable threat to humans and ecosystems, so there is a need to develop safer and more effective methods than conventional strategies for the optimal removal of these compounds. In this study, four [...] Read more.
The high consumption and emission of sulfonamide antibiotics (SAs) have a considerable threat to humans and ecosystems, so there is a need to develop safer and more effective methods than conventional strategies for the optimal removal of these compounds. In this study, four SAs with different substituents, sulfadiazine (SDZ), sulfamerazine (SMR), sulfamethoxazole (SMX), and sulfamethazine (SMZ) were removed by a pure culture of Paenarthrobacter ureafaciens YL1. The effect of the initial SAs concentration on the growth rate of strain YL1 was investigated. The results showed that the strain YL1 effectively removed various SAs in the concentration range of 0.05–2.4 mmol·L−1. The Haldane model was used to perform simulations of the experimental data, and the regression coefficient of the model indicated that the model had a good predictive ability. During SAs degradation, the maximum specific growth rate of strain YL1 was ranked as SMX > SDZ > SMR > SMZ with constants of 0.311, 0.304, 0.302, and 0.285 h−1, respectively. In addition, the biodegradation of sulfamethoxazole (SMX) with a five-membered substituent was the fastest, while the six-membered substituent of SMZ was the slowest based on the parameters of the kinetic equation. Also, density functional theory (DFT) calculations such as frontier molecular orbitals (FMOs), and molecular electrostatic potential map analysis were performed. It was evidenced that different substituents in SAs can affect the molecular orbital distribution and their stability, which led to the differences in the growth rate of strain YL1 and the degradation rate of SAs. Furthermore, the toxicity of P. ureafaciens is one of the crucial factors affecting the biodegradation rate: the more toxic the substrate and the degradation product are, the slower the microorganism grows. This study provides a theoretical basis for effective bioremediation using microorganisms in SAs-contaminated environments. Full article
(This article belongs to the Special Issue Research Progress of Microorganisms in Wastewater Treatment)
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12 pages, 854 KiB  
Article
Hydrogen-Rich Water Can Restrict the Formation of Biogenic Amines in Red Beet Pickles
by Duried Alwazeer, Menekşe Bulut and Yasemin Çelebi
Fermentation 2022, 8(12), 741; https://doi.org/10.3390/fermentation8120741 - 14 Dec 2022
Cited by 5 | Viewed by 1947
Abstract
Fermented foods are considered the main sources of biogenic amines (BAs) in the human diet while lactic acid bacteria (LAB) are the main producers of BAs. Normal water (NW) and hydrogen-rich water (HRW) were used for preparing red beet pickles, i.e., NWP and [...] Read more.
Fermented foods are considered the main sources of biogenic amines (BAs) in the human diet while lactic acid bacteria (LAB) are the main producers of BAs. Normal water (NW) and hydrogen-rich water (HRW) were used for preparing red beet pickles, i.e., NWP and HRWP, respectively. The formation of BAs, i.e., aromatic amines (tyramine, 2-phenylethylamine), heterocyclic amines (histamine, tryptamine), and aliphatic di-amines (putrescine), was analyzed in both beet slices and brine of NWPs and HRWPs throughout the fermentation stages. Significant differences in redox value (Eh7) between NWP and HRWP brine samples were noticed during the first and last fermentation stages with lower values found for HRWPs. Total mesophilic aerobic bacteria (TMAB), yeast–mold, and LAB counts were higher for HRWPs than NWPs for all fermentation stages. Throughout fermentation stages, the levels of all BAs were lower in HRWPs than those of NWPs, and their levels in brines were higher than those of beets. At the end of fermentation, the levels (mg/kg) of BAs in NWPs and HRWPs were, respectively: tyramine, 72.76 and 61.74 (beet) and 113.49 and 92.67 (brine), 2-phenylethylamine, 48.00 and 40.00 (beet) and 58.01 and 50.19 (brine), histamine, 67.89 and 49.12 (beet) and 91.74 and 70.92 (brine), tryptamine, 93.14 and 77.23 (beet) and 119.00 and 93.11 (brine), putrescine, 81.11 and 63.56 (beet) and 106.75 and 85.93 (brine). Levels of BAs decreased by (%): 15.15 and 18.35 (tyramine), 16.67 and 13.44 (2-phenylethylamine), 27.65 and 22.7 (histamine), 17.09 and 21.76 (tryptamine), and 21.64 and 19.5 (putrescine) for beet and brine, respectively, when HRW was used in pickle preparation instead of NW. The results of this study suggest that the best method for limiting the formation of BAs in pickles is to use HRW in the fermentation phase then replace the fermentation medium with a new acidified and brined HRW followed by a pasteurization process. Full article
(This article belongs to the Special Issue Bioprocess and Metabolic Engineering)
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13 pages, 4062 KiB  
Article
The Influence of Seasons on the Composition of Microbial Communities and the Content of Lactic Acid during the Fermentation of Fen-Flavor Baijiu
by Xinyi Zhao, Jianghua Li, Guocheng Du, Jian Chen, Tingyue Ren, Junyan Wang, Ying Han, Pan Zhen and Xinrui Zhao
Fermentation 2022, 8(12), 740; https://doi.org/10.3390/fermentation8120740 - 14 Dec 2022
Cited by 1 | Viewed by 1429
Abstract
During the fermentation of Fen-flavor Baijiu, the number of lactic acid bacteria is high in summer, resulting in excessive lactic acid and an unpleasant astringent taste. Thus, it is necessary to identify the critical influence factors for the formation of lactic acid and [...] Read more.
During the fermentation of Fen-flavor Baijiu, the number of lactic acid bacteria is high in summer, resulting in excessive lactic acid and an unpleasant astringent taste. Thus, it is necessary to identify the critical influence factors for the formation of lactic acid and the composition of the microbial community in the fermented grains during the brewing process of Fen-flavor Baijiu in cold and hot seasons using HPLC and high-throughput sequencing technology. The results suggest that Lactobacillus acetotolerans is the key microorganism causing different contents of lactic acid in fermented grains and that Lactobacillus plantarum is a favorable factor for acid production in the fermentation process during hot seasons. Twelve lactic-acid-producing strains were isolated from the fermented grains at the latter stage of fermentation, and the analysis of these strains showed that the Lactobacillus plantarum LP strain has the strongest capacity for lactic acid production and the Lacticaseibacillus rhamnosus LR strain has the strongest capacity for acid production, respectively. In addition, the Lentilactobacillus hilgardii LH strain has the characteristics of both acid and alcohol resistance. The results obtained from this study provide a reference for reducing the content of lactic acid in summer and have potential value for further improving the quality of Fen-flavor Baijiu. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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13 pages, 1436 KiB  
Article
Evaluating Bio-Hydrogen Production Potential and Energy Conversion Efficiency from Glucose and Xylose under Diverse Concentrations
by Zi-Han Wang, Jing-Yan Tan, Yu-Tong Zhang, Nan-Qi Ren and Lei Zhao
Fermentation 2022, 8(12), 739; https://doi.org/10.3390/fermentation8120739 - 14 Dec 2022
Cited by 2 | Viewed by 1840
Abstract
Lignocellulose bioconversion to hydrogen has been proposed as a promising solution to augment the fossil fuel dominated energy market. However, little is known about the effects of the substrate concentration supplied on hydrogen production. Herein, the hydrogen producing bacteria Thermoanaerobacter thermosaccharolyticum W16 feeding [...] Read more.
Lignocellulose bioconversion to hydrogen has been proposed as a promising solution to augment the fossil fuel dominated energy market. However, little is known about the effects of the substrate concentration supplied on hydrogen production. Herein, the hydrogen producing bacteria Thermoanaerobacter thermosaccharolyticum W16 feeding with respective glucose, xylose, and glucose and xylose mixture (glucose–xylose) at different concentrations was evaluated, to study whether substrate concentration could impact the lignocellulose bioconversion to hydrogen and the associated kinetics. An average bio-hydrogen yield of 1.40 ± 0.23 mol H2·mol−1 substrate was obtained at an average substrate concentration of 60.89 mM. The maximum bio-hydrogen production rate of 0.25 and 0.24 mol H2·mol−1 substrate h−1 was achieved at a substrate concentration of 27.75 mM glucose and 30.82 mM glucose–xylose, respectively, while the value reached the high point of 0.08 mol H2·mol−1 xylose·h−1 at 66.61 mM xylose. Upon further energy conversion efficiency (ESE) analysis, a substrate of 10 g·L−1 (amounting to 55.51 mM glucose, 66.61 mM xylose or 60.55 mM glucose–xylose) provided the maximum ESE of 15.3 ± 0.3%, which was 15.3% higher than that obtained at a substrate concentration of 5 g·L−1 (amounting to 27.75 mM glucose, 33.30 mM xylose or 30.28 mM glucose–xylose). The findings could be helpful to provide effective support for the future development of efficient and sustainable lignocellulosic bio-hydrogen production. Full article
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18 pages, 2196 KiB  
Article
Engineering Escherichia coli for Efficient Aerobic Conversion of Glucose to Malic Acid through the Modified Oxidative TCA Cycle
by Alexandra Yu. Skorokhodova, Anastasiya A. Stasenko, Natalya V. Krasilnikova, Andrey Yu. Gulevich and Vladimir G. Debabov
Fermentation 2022, 8(12), 738; https://doi.org/10.3390/fermentation8120738 - 14 Dec 2022
Cited by 2 | Viewed by 1948
Abstract
Malic acid is a versatile building-block chemical that can serve as a precursor of numerous valuable products, including food additives, pharmaceuticals, and biodegradable plastics. Despite the present petrochemical synthesis, malic acid, being an intermediate of the TCA cycle of a variety of living [...] Read more.
Malic acid is a versatile building-block chemical that can serve as a precursor of numerous valuable products, including food additives, pharmaceuticals, and biodegradable plastics. Despite the present petrochemical synthesis, malic acid, being an intermediate of the TCA cycle of a variety of living organisms, can also be produced from renewable carbon sources using wild-type and engineered microbial strains. In the current study, Escherichia coli was engineered for efficient aerobic conversion of glucose to malic acid through the modified oxidative TCA cycle resembling that of myco- and cyanobacteria and implying channelling of 2-ketoglutarate towards succinic acid via succinate semialdehyde formation. The formation of succinate semialdehyde was enabled in the core strain MAL 0 (∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆ptsG, PL-glk, Ptac-galP, ∆aceBAK, ∆glcB) by the expression of Mycobacterium tuberculosis kgd gene. The secretion of malic acid by the strain was ensured, resulting from the deletion of the mdh, maeA, maeB, and mqo genes. The Bacillus subtilis pycA gene was expressed in the strain to allow pyruvate to oxaloacetate conversion. The corresponding recombinant was able to synthesise malic acid from glucose aerobically with a yield of 0.65 mol/mol. The yield was improved by the derepression in the strain of the electron transfer chain and succinate dehydrogenase due to the enforcement of ATP hydrolysis and reached 0.94 mol/mol, amounting to 94% of the theoretical maximum. The implemented strategy offers the potential for the development of highly efficient strains and processes of bio-based malic acid production. Full article
(This article belongs to the Special Issue Bioprocess and Metabolic Engineering)
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15 pages, 1062 KiB  
Article
The Effect of Different Fining Treatments on Phenolic and Aroma Composition of Grape Musts and Wines
by Zdenek Rihak, Bozena Prusova, Kamil Prokes and Mojmir Baron
Fermentation 2022, 8(12), 737; https://doi.org/10.3390/fermentation8120737 - 13 Dec 2022
Cited by 1 | Viewed by 1310
Abstract
The study evaluated the effect of different fining treatments such as oenological additives and the influence of oxygen and hyperoxygenation on the phenolic and aroma composition of grape musts and wines. The oxidative method, hyperoxygenation and fining agents polyvinyl polypyrrolidone (PVPP), pea protein [...] Read more.
The study evaluated the effect of different fining treatments such as oenological additives and the influence of oxygen and hyperoxygenation on the phenolic and aroma composition of grape musts and wines. The oxidative method, hyperoxygenation and fining agents polyvinyl polypyrrolidone (PVPP), pea protein and chitosan were used for the removal of phenolic compounds compared to the control experiment. The content of phenolic substances was determined by high performance liquid chromatography. A total of 24 volatiles—higher alcohols, ethyl esters and acetate esters were determined using gas chromatography-mass spectrometry. A lower concentration of caftaric acid was observed in hyperoxygenated (0.21 mg·L−1), oxidated (0.37 mg·L−1), PVPP-treated (35.50 mg·L−1), pea protein-treated (42.56 mg·L−1) and chitosan-treated variants (44.40 mg·L−1), in contrast to the control must (caftaric acid 50.38 mg·L−1). In the final wine, the results were similar with a lower concentration of caftaric acid in hyperoxygenated (7.10 mg·L−1), oxidated (14.88 mg·L−1), PVPP-treated (23.49 mg·L−1), pea protein-treated (29.49 mg·L−1) and chitosan-treated variant (30.02 mg·L−1), in contrast to the control wine (caftaric acid 32.19 mg·L−1). Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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9 pages, 564 KiB  
Article
Methane Production of Pistia Stratiotes as a Single Substrate and as a Co-Substrate with Dairy Cow Manure
by Sutaryo Sutaryo, Aldila Nugrahaini Sempana, Rifo Martio Mulya, Dian Sulistyaningrum, Mochamad Sofyan Ali, Rafi Ihsa Damarjati, Endang Purbowati, Retno Adiwinarti and Agung Purnomoadi
Fermentation 2022, 8(12), 736; https://doi.org/10.3390/fermentation8120736 - 13 Dec 2022
Cited by 3 | Viewed by 1483
Abstract
Mono anaerobic digestion (AD) of dairy cow manure (DCM) is constrained by high moisture, ash and crude fibre content. Anaerobic co-digestion DCM and other biomass is one of the methods to overcome this drawback. This study aimed to evaluate: methane production from different [...] Read more.
Mono anaerobic digestion (AD) of dairy cow manure (DCM) is constrained by high moisture, ash and crude fibre content. Anaerobic co-digestion DCM and other biomass is one of the methods to overcome this drawback. This study aimed to evaluate: methane production from different parts of Pistia stratiotes (PS), methane production from the mixed substrate of PS and DCM in different proportions of PS in terms of volatile solids (VS) (0%, 7.99%, 14.91%, and 20.94%) using continuous digesters, and the potency of biogas yield from the digested slurry. Methane production from the whole plant, shoot system, and root of PS was 405.68, 416.82, and 326.42 L/kg VS, respectively. The highest methane production was obtained from the shoot system because that part contained higher crude protein and hemicellulose contents. Utilization of PS as a co-substrate for AD of the DCM can increase methane production by 28.65–56.98% compared to the control digester. No effect on pH, total ammonia nitrogen and total volatile fatty acid indicated that PS was suitable as a co-substrate of DCM and can significantly increase methane yield of the mixed substrate. AD of digested slurries showed that to recover the biogas production from the mixed substrate, the post-digestion treatment should be applied before the slurries are used as organic fertilizer. Full article
(This article belongs to the Special Issue Energy Converter: Anaerobic Digestion)
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15 pages, 2393 KiB  
Article
Saudi Traditional Fermented Goat Milk Protects against Experimental Non-Alcoholic Fatty Liver Disease by Hypoglycaemic and Antioxidant Potentials
by Khadijah M. Altamimy, Ghedeir M. Alshammari, Abu ElGasim A. Yagoub, Norah A. Albekairi, Samiyah Alshehri, Ali Saleh and Mohammed Abdo Yahya
Fermentation 2022, 8(12), 735; https://doi.org/10.3390/fermentation8120735 - 13 Dec 2022
Cited by 2 | Viewed by 2401
Abstract
This study examined the effect of fermented goat milk (oggtt) against non-alcoholic fatty liver disease (NAFLD) in rats induced by chronic high-fat diet (HFD) treatments. Both control-fed and HFD-fed adult male rats received the same vehicle or treatment with two doses of freshly [...] Read more.
This study examined the effect of fermented goat milk (oggtt) against non-alcoholic fatty liver disease (NAFLD) in rats induced by chronic high-fat diet (HFD) treatments. Both control-fed and HFD-fed adult male rats received the same vehicle or treatment with two doses of freshly collected oggtt (2 mL or 5 mL) for 12 weeks (n = 8/group). The treatment of the control and HFD-fed rats with oggtt in both doses significantly reduced weight gain, but fasting serum glucose and insulin levels as well as HOMA-IR levels were lowered only in the HFD-fed rats. Treatment improved HFD-induced glucose and insulin homeostasis impairment as measured by the oral glucose tolerance test. Both doses of oggtt reduced serum levels of liver function markers and C-reactive protein (CRP) as well as hepatic levels of malondialdehyde (MDA), tumour necrosis factor-α (TNF-α), and in-terlukin-6 (IL-6) in HFD-fed rats. In addition, the oggtt doses reduced serum and hepatic levels of triglycerides (TGs) and cholesterol (CHOL) as well as serum levels of low-density lipoproteins (LDL) in these rats. These biochemical endpoints were reflected by the improvement in liver histology and reduction in the number of fatty vacuolated and pyknotic cells. In both the control and HFD-fed rats, oggtt at both doses stimulated levels of superoxide dismutase (SOD) and glutathione (GSH). All these effects were more profound with the highest dose of oggtt. In conclusion, the finding of this study strongly supports the use of oggtt as a functional food to treat NAFLD, as it has shown hypoglycaemic and antioxidant properties. Full article
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14 pages, 1691 KiB  
Article
Life Cycle Assessment of Bioethanol Production: A Case Study from Poplar Biomass Growth in the U.S. Pacific Northwest
by Rodrigo Morales-Vera, Leonardo Vásquez-Ibarra, Felipe Scott, Maureen Puettmann and Richard Gustafson
Fermentation 2022, 8(12), 734; https://doi.org/10.3390/fermentation8120734 - 13 Dec 2022
Cited by 5 | Viewed by 3215
Abstract
Biomass appears to be one of the most prominent renewable resources for biofuels such as bioethanol, mainly due to its better environmental performance compared with fossil fuels. This study addresses a comprehensive environmental performance of bioethanol production, employing empirical data from hybrid poplar [...] Read more.
Biomass appears to be one of the most prominent renewable resources for biofuels such as bioethanol, mainly due to its better environmental performance compared with fossil fuels. This study addresses a comprehensive environmental performance of bioethanol production, employing empirical data from hybrid poplar grown in the U.S. The study considers 1 MJ as a functional unit and employs a cradle-to-grave approach, which entails the feedstock and harvesting production of poplar, transport to a biorefinery, bioconversion of the biomass process, and fuel use. On average, bioconversion is the main contributor to environmental degradation in all the categories evaluated (77%). The second main contributor is either the feedstock and harvesting production of poplar (17%) or fuel use (6%), depending on the environmental category. Thus, focusing on only one category may induce a misinterpretation of the environmental performance of bioethanol production. Finally, environmental credits in the global warming potential (GWP) category were obtained from the carbon sequestered in the biomass during the growing period and from avoided fossil fuel emissions due to electricity production from a renewable source. This means that the net GWP of the life cycle of bioethanol from poplar biomass is slightly negative (−1.05 × 10−3 kg CO2-eq·MJ−1). Full article
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19 pages, 2366 KiB  
Article
Exploring the Core Microbiota of Four Different Traditional Fermented Beverages from the Colombian Andes
by Johannes Delgado-Ospina, Luisa Fernanda Puerta-Polanco, Carlos David Grande-Tovar, Raúl Alberto Cuervo, Diana Paola Navia-Porras, Luis Gabriel Poveda-Perdomo, Fabián Felipe Fernández-Daza and Clemencia Chaves-López
Fermentation 2022, 8(12), 733; https://doi.org/10.3390/fermentation8120733 - 13 Dec 2022
Cited by 1 | Viewed by 2201
Abstract
Fermentation is an ancient process used to prepare and preserve food. Currently, fermented beverages are part of the culture of people living in the Colombian Andean Region, and they are a vital part of their cosmology and ancestral vision. Chicha, Forcha, Champús, and [...] Read more.
Fermentation is an ancient process used to prepare and preserve food. Currently, fermented beverages are part of the culture of people living in the Colombian Andean Region, and they are a vital part of their cosmology and ancestral vision. Chicha, Forcha, Champús, and Masato are some of the most common Colombian Andes region’s traditional fermented beverages. These drinks come from the fermentation of maize (Zea maize), but other cereals such as wheat or rye, could be used. The fermentation is carried out by a set of bacteria and yeasts that provide characteristic organoleptic properties of each beverage. In this work, the information collected from the metagenomics analyses by sequencing ITS 1-4 (Internal Transcriber Spacer) and the 16S ribosomal gene for fungi and the V3-V4 region of the rDNA for bacteria allowed us to identify the diversity present in these autochthonous fermented beverages made with maize. The sequencing analysis showed the presence of 39 bacterial and 20 fungal genera. In addition, we determined that only nine genera of bacteria and two genera of fungi affect the organoleptic properties of smell, colour, and flavour, given the production of compounds such as lactic acid, alcohol, and phenols, highlighting the critical role of these microorganisms. Our findings provide new insights into the core microbiota of these beverages, represented by Lactobacillus fermentum, Acetobacter pasteurianus, and Saccharomyces cerevisiae. Full article
(This article belongs to the Special Issue Fermentation and Bioactive Metabolites 3.0)
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12 pages, 2142 KiB  
Article
Influence of Lactobacillus (LAB) Fermentation on the Enhancement of Branched Chain Amino Acids and Antioxidant Properties in Bran among Wheat By-Products
by Thinzar Aung, Seung-Soo Park and Mi-Jeong Kim
Fermentation 2022, 8(12), 732; https://doi.org/10.3390/fermentation8120732 - 12 Dec 2022
Cited by 2 | Viewed by 1533
Abstract
The main objective of this study was to enhance the nutritional properties, including branched chain amino acids (BCAAs), through the solid-state fermentation (SSF) of wheat bran (WB) using lactic acid bacteria (LAB). The physicochemical properties, amino acid profiles, bioactive components, and antioxidant properties [...] Read more.
The main objective of this study was to enhance the nutritional properties, including branched chain amino acids (BCAAs), through the solid-state fermentation (SSF) of wheat bran (WB) using lactic acid bacteria (LAB). The physicochemical properties, amino acid profiles, bioactive components, and antioxidant properties of raw and sterilized WB were compared with those of WB fermented with five different LAB strains. The highest level of BCAAs, isoleucine (Ile; 2.557 ± 0.05 mg/100 g), leucine (Leu; 7.703 ± 0.40 mg/100 g), and valine (Val; 7.207 ± 0.37 mg/100 g), was displayed in the WB fermented with Lactobacillus acidophilus (L.A WB). In addition, L.A WB showed the highest amount of total phenolic and flavonoid contents (2.80 mg GAE/g and 1.01 mg CE/g, respectively), and the highest Trolox equivalent antioxidant capacity (9.88 mM TE/g). Statistical analysis clearly revealed that L.A WB presented the highest abundance of branched chain amino acids as well as bioactive components. Overall, this study distinctly implemented the possibility of fermented WB with enhanced BCAAs for application in future functional food through experimental and statistical observations. Full article
(This article belongs to the Special Issue Food Wastes: Feedstock for Value-Added Products: 4th Edition)
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11 pages, 1041 KiB  
Article
Citric Acid Production by Yarrowia lipolytica NRRL Y-1094: Optimization of pH, Fermentation Time and Glucose Concentration Using Response Surface Methodology
by Bilge Sayın Börekçi, Mükerrem Kaya and Güzin Kaban
Fermentation 2022, 8(12), 731; https://doi.org/10.3390/fermentation8120731 - 12 Dec 2022
Cited by 3 | Viewed by 1469
Abstract
In this study, three Yarrowia lipolytica strains (Y. lipolytica NRRL Y-1094, Y. lipolytica NRRL YB-423 and Y. lipolytica IFP29) were screened for acid-production capacity and the maximum zone-area was formed by Y. lipolytica NRRL Y-1094. The strain was then selected as a [...] Read more.
In this study, three Yarrowia lipolytica strains (Y. lipolytica NRRL Y-1094, Y. lipolytica NRRL YB-423 and Y. lipolytica IFP29) were screened for acid-production capacity and the maximum zone-area was formed by Y. lipolytica NRRL Y-1094. The strain was then selected as a potential citric-acid (CA) producer for further studies. The CA production by Y. lipolytica NRRL Y-1094 was optimized using response surface methodology (RSM) and considering three factors, comprising initial pH-value, fermentation time, and initial glucose-concentration. The highest CA-concentration was 30.31 g/L under optimum conditions (pH 5.5, 6 days, and 125 g/L glucose) in shake flasks. It has been reported that this result gives better results than many productions with shake flasks. According to estimated regression-coefficients for CA concentration, the fermentation time had the greatest impact on CA production, followed by the substrate concentration and initial pH-level, respectively. On the other hand, this study is a fundamental step in solving and optimizing the production mechanism of Y. lipolytica NRRL Y-1094, a microorganism that has not yet been used in CA production with a glucose-based medium. The results suggest that future studies can perform higher yields by optimizing other medium constituents and environmental factors. Full article
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15 pages, 1640 KiB  
Article
Evaluation of the Thermal Processes on Changing the Phenotypic Characteristics of Escherichia coli Strains from Ice Cream Compared to Non-Pasteurized Milk
by Maryam Ranjbar, Reza Nedaeinia, Mohammad Goli and Sharifeh Shahi
Fermentation 2022, 8(12), 730; https://doi.org/10.3390/fermentation8120730 - 12 Dec 2022
Cited by 1 | Viewed by 1406
Abstract
Escherichia coli (E. coli) is shocked by various temperature processes in milk, which forces the organism to make proteins as a result of changes in the synthesis of enzymes that might give the strain special characteristics. The purpose of this study [...] Read more.
Escherichia coli (E. coli) is shocked by various temperature processes in milk, which forces the organism to make proteins as a result of changes in the synthesis of enzymes that might give the strain special characteristics. The purpose of this study was to investigate the effects of the heat shock factor on changing the results of biochemical and molecular tests among E. coli strains obtained from ice cream and non-pasteurized milk when compared to a reference strain from the American-type culture collection (ATCC) in order to determine the phenotypic variation caused by the temperature conditions of the manufacturing process. Furthermore, isolates with characteristics similar to E. coli were discovered, but they were not E. coli and caused some ambiguity. To test the E. coli contamination of traditional and industrial ice cream, 82 samples were chosen at random. SDS-PAGE and 16S rDNA sequencing were carried out, as well as phenotypic testing. Isolated strains did not exactly match the reference strain. The results of biochemical testing and protein analysis revealed that the isolates were diverse. Samples E. coli phenons were classified. In the electrophoresis, the ice cream strain had two protein bands in the 20.75 and 23.59 kDa ranges that were distinct from the reference strain. These isolates appear to experience alterations in enzyme characteristics and structural proteins as a result of being exposed to various temperature conditions, such as pasteurization and frigidity. When compared to the reference strain, the calculated similarity percentage of the elicited isolate varied from 60 to 70%. The electrophoretic patterns of E. coli isolated elicited from milk samples differed from E. coli isolated obtained from the ice cream. The distinctions were in the intensity or position of the bands. The results also revealed that when isolates are subjected to thermal stresses, they exhibit a pattern similar to that of ice cream isolates. These considerations are made because a change in protein composition might result in a change in biochemical features, resulting in uncertainty in its identification. Sequences revealed that the sequences were related to E. coli 16S rDNA, despite differences in phenotypic and electrophoretic features between the isolated bacteria and the reference strain E. coli ATCC 25922. Our findings revealed that 16S rDNA could potentially be used to instantly implement an appropriate preventive measure for the purpose of identifying this type of bacteria and avoid some ambiguity. Full article
(This article belongs to the Special Issue Dairy Fermentation)
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11 pages, 3120 KiB  
Article
Using Machine Learning Methods to Predict the ß-Poly (L-Malic Acid) Production by Different Substrates Addition and Secondary Indexes in Strain Aureobasidium melanogenum
by Genan Wang, Jiaqian Li, Shuxian Wang, Yutong Li, Shiwei Chen, Lina Zhang, Tingbin Zhao, Haisong Yin, Shiru Jia and Changsheng Qiao
Fermentation 2022, 8(12), 729; https://doi.org/10.3390/fermentation8120729 - 12 Dec 2022
Viewed by 1177
Abstract
ß-poly (L-malic acid) (PMLA) is a polyester ligated by malate subunits. It has a wide prospective application as an anti-cancer drug carrier, and its malate subunits have a great application in the food industry. The strain Aureoabsidium melanogenum could produce a high amount [...] Read more.
ß-poly (L-malic acid) (PMLA) is a polyester ligated by malate subunits. It has a wide prospective application as an anti-cancer drug carrier, and its malate subunits have a great application in the food industry. The strain Aureoabsidium melanogenum could produce a high amount of PMLA during fermentation, and different substrates addition could influence the production. In this study, we directly added potassium acetate, corn steep liquor, MgSO4, MnSO4, vitamin B1, vitamin B2, and nicotinamide as the fermentation substrate to the basic fermentation medium based on a generated random matrix that represented the added value. The PMLA production and four secondary indexes, pH, biomass, osmotic pressure, and viscosity were measured after 144 h fermentation. Finally, a total of 212 samples were collected as the dataset, by which the machine learning methods were deployed to predict the PMLA production by different substrates’ concentrations and the secondary indexes. The results indicated that PMLA production was negatively correlated with corn steep liquor and betaine and positively correlated with potassium acetate. The PMLA production could be predicted using all different substrates’ concentrations with a Mean Absolute Error (MAE) of 4.164 g/L and with an MAE of 6.556 g/L by different secondary indexes. Finally, the convolutional neural network (CNN) was applied to predict the PMLA production by fermentation medium images, in which the collected images were categorized into three groups, 0–20 g/L, 21–40 g/L, and >41 g/L, based on the PMLA production. The CNN model could predict the production with high accuracy. The methods and results presented in this study provided new insight into evaluating different substrates concentration on PMLA production and demonstrating the possibility of using the convolutional neural network model in the PMLA fermentation industry. Full article
(This article belongs to the Section Industrial Fermentation)
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36 pages, 1345 KiB  
Review
Agro-Industrial Wastewaters for Algal Biomass Production, Bio-Based Products, and Biofuels in a Circular Bioeconomy
by Júlio Cesar de Carvalho, Denisse Tatiana Molina-Aulestia, Walter José Martinez-Burgos, Susan Grace Karp, Maria Clara Manzoki, Adriane Bianchi Pedroni Medeiros, Cristine Rodrigues, Thamarys Scapini, Luciana Porto de Souza Vandenberghe, Sabrina Vieira, Adenise Lorenci Woiciechowski, Vanete Thomaz Soccol and Carlos Ricardo Soccol
Fermentation 2022, 8(12), 728; https://doi.org/10.3390/fermentation8120728 - 12 Dec 2022
Cited by 9 | Viewed by 4333
Abstract
Recycling bioresources is the only way to sustainably meet a growing world population’s food and energy needs. One of the ways to do so is by using agro-industry wastewater to cultivate microalgae. While the industrial production of microalgae requires large volumes of water, [...] Read more.
Recycling bioresources is the only way to sustainably meet a growing world population’s food and energy needs. One of the ways to do so is by using agro-industry wastewater to cultivate microalgae. While the industrial production of microalgae requires large volumes of water, existing agro-industry processes generate large volumes of wastewater with eutrophicating nutrients and organic carbon that must be removed before recycling the water back into the environment. Coupling these two processes can benefit the flourishing microalgal industry, which requires water, and the agro-industry, which could gain extra revenue by converting a waste stream into a bioproduct. Microalgal biomass can be used to produce energy, nutritional biomass, and specialty products. However, there are challenges to establishing stable and circular processes, from microalgae selection and adaptation to pretreating and reclaiming energy from residues. This review discusses the potential of agro-industry residues for microalgal production, with a particular interest in the composition and the use of important primary (raw) and secondary (digestate) effluents generated in large volumes: sugarcane vinasse, palm oil mill effluent, cassava processing waster, abattoir wastewater, dairy processing wastewater, and aquaculture wastewater. It also overviews recent examples of microalgae production in residues and aspects of process integration and possible products, avoiding xenobiotics and heavy metal recycling. As virtually all agro-industries have boilers emitting CO2 that microalgae can use, and many industries could benefit from anaerobic digestion to reclaim energy from the effluents before microalgal cultivation, the use of gaseous effluents is also discussed in the text. Full article
(This article belongs to the Special Issue Algal Biomass: From Bioproducts to Biofuels)
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12 pages, 2299 KiB  
Article
Preliminary Studies of Bio-Fortification of Yoghurt with Chromium
by Mohsen A. Zommara, Elsayed G. Bedeer, Ehab Kotb Elmahallawy, Amin A. Hafiz, Ashraf Albrakati and Seham Swelam
Fermentation 2022, 8(12), 727; https://doi.org/10.3390/fermentation8120727 - 12 Dec 2022
Viewed by 1445
Abstract
Yoghurt is a delectable fermented milk product suitable for all ages. Chromium (Cr), a trace mineral is found in two forms: trivalent and hexavalent. Recent studies have shown that the Cr (III), or chromium picolinate (Cri), is beneficial for carbohydrate metabolism. Thus, Cr [...] Read more.
Yoghurt is a delectable fermented milk product suitable for all ages. Chromium (Cr), a trace mineral is found in two forms: trivalent and hexavalent. Recent studies have shown that the Cr (III), or chromium picolinate (Cri), is beneficial for carbohydrate metabolism. Thus, Cr supplements are used to treat diabetes and manage blood sugar. However, the effect of the incorporation of Cri on starter growth and the quality of yoghurt still needs to be determined. In this study, we aim to produce Cr (CrPi)-fortified yoghurt to fulfil the proposed recommended daily allowance (RDA) of Cr (35–50 µg/day for adults). Additionally, it might act as a nutraceutical for persons with special medical conditions, such as patients with obesity or type 2 diabetes mellitus disease. In this respect, the effect of different concentrations of CrPi, (1, 2, 5, 10, 20 ppm) chromium chloride [Cr (III)] (1, 2, 3, 4, 5 ppm), and potassium chromate [Cr (VI)] (1, 2 ppm) on the activity of yoghurt starter culture were investigated in vitro on de Man, Rogosa, and Sharpe (MRS) media. Compared to the control (without Cr), the obtained data revealed significant inhibition of the yoghurt starter culture by Cr (VI) at 2 ppm compared to Cr (III), which did not affect the bacterial growth up to 5 ppm and was comparable with CrPi [Cr (III)]. We also produced yoghurt supplemented with two doses of Cr (0.25 and 0.5 ppm). We did not observe any significant differences in the physicochemical, rheological, microbiological, and sensory properties of the Cr-fortified yoghurt and the control up to 2 weeks in cold storage. These results clearly indicate that CrPi (0.25 and 0.5 ppm) can be used to manufacture yoghurt with the RDA for intact Cr without affecting its quality. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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13 pages, 1558 KiB  
Article
Analysis of the Genome Architecture of Lacticaseibacillus paracasei UNQLpc 10, a Strain with Oenological Potential as a Malolactic Starter
by Nestor Gabriel Iglesias, Marina Edith Navarro, Natalia Soledad Brizuela, Danay Valdés La Hens, Liliana Carmen Semorile, Emma Elizabeth Tymczyszyn and Bárbara Mercedes Bravo Ferrada
Fermentation 2022, 8(12), 726; https://doi.org/10.3390/fermentation8120726 - 11 Dec 2022
Cited by 2 | Viewed by 1048
Abstract
The Lacticaseibacillus paracasei UNQLpc 10 strain was isolated from a Malbec wine produced in North Patagonia, Argentina, and identified by 16S rRNA gene sequencing. The aim of this work was to obtain the fully assembled genome of the UNQLpc 10 strain, analyze its [...] Read more.
The Lacticaseibacillus paracasei UNQLpc 10 strain was isolated from a Malbec wine produced in North Patagonia, Argentina, and identified by 16S rRNA gene sequencing. The aim of this work was to obtain the fully assembled genome of the UNQLpc 10 strain, analyze its structure, and evaluate the possible functions of the predicted genes with regard to its oenological potential as a malolactic starter. UNQLpc10 is the first whole assembled genome of an oenological strain of Lcb. paracasei reported in databases. This information is of great interest inexpanding the knowledge of diversity of oenological lactic acid bacteria and in searching for new candidate species/strains to design starter cultures. The in silico genome-wide analysis of UNQLpc 10 confirms the existence of genes encoding enzymes involved in the synthesis of several metabolites of oenological interest, and proteins related to stress responses. Furthermore, when UNQLpc 10 was incubated in synthetic wine, it exhibited a very good survival and L-malic acid consumption ability. Full article
(This article belongs to the Special Issue Recent Applications of Biotechnology in Wine and Beer Production)
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