Fermentation

19 pages, 2018 KiB

Open AccessArticle

Characteristics and Anaerobic Co-Digestion of Press Water from Wood Fuel Preparation and Digested Sewage Sludge

by Gregor Sailer, Florian Empl, Daniel Kuptz, Martin Silberhorn, Darwin Ludewig, Simon Lesche, Stefan Pelz and Joachim Müller

Fermentation 2022, 8(1), 37; https://doi.org/10.3390/fermentation8010037 - 17 Jan 2022

Cited by 3 | Viewed by 3344

Abstract

Technical drying of harvested wood fuels is heat and energy consuming, while natural pre-drying in the forest, e.g., in stacks or storage piles, is accompanied by energy losses through natural degradation processes. Dewatering of energy wood by mechanical pressing is an innovative method [...] Read more.

Technical drying of harvested wood fuels is heat and energy consuming, while natural pre-drying in the forest, e.g., in stacks or storage piles, is accompanied by energy losses through natural degradation processes. Dewatering of energy wood by mechanical pressing is an innovative method to reduce the moisture content prior to thermal drying while producing press waters (PW, also referred to as wood juice) as a by-product. To date, the characteristics and utilization potentials of PW are largely unknown. In this study, three different spruce- and poplar-based PW were analyzed for their characteristics such as dry matter (DM), organic dry matter (oDM) concentration, pH-value, element concentration or chemical compounds. Additionally, they were used for anaerobic digestion (AD) experiments with digested sewage sludge (DSS) serving as inoculum. The fresh matter-based DM concentrations of the PW were between 0.4 and 3.2%, while oDM concentrations were between 87 and 89%_DM. The spruce-based PW were characterized by lower pH-values of approx. 4.4, while the poplar-based PW was measured at pH 8. In the AD experiments, DSS alone (blank variant) achieved a specific methane yield of 95 ± 26 mL/g_oDM, while the mixture of spruce-based PW and DSS achieved up to 160 ± 12 mL/g_oDM, respectively. With further research, PW from wood fuel preparation offer the potential to be a suitable co-substrate or supplement for AD processes. Full article

(This article belongs to the Special Issue Recent Trends in Biogenic Gas, Waste and Wastewater Fermentation)

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13 pages, 1235 KiB

Open AccessArticle

The Influence of Traditional and Immobilized Yeast on the Amino-Acid Content of Sparkling Wine

by Kamil Prokes, Mojmir Baron, Jiri Mlcek, Tunde Jurikova, Anna Adamkova, Sezai Ercisli and Jiri Sochor

Fermentation 2022, 8(1), 36; https://doi.org/10.3390/fermentation8010036 - 17 Jan 2022

Cited by 7 | Viewed by 2767

Abstract

This article focuses on the effect of yeast strains, vintage, and must sugar content on the amino-acid content of sparkling wines produced by the traditional method. In the experiment, the amino-acid concentrations before and after secondary fermentation, depending on the type of yeast [...] Read more.

This article focuses on the effect of yeast strains, vintage, and must sugar content on the amino-acid content of sparkling wines produced by the traditional method. In the experiment, the amino-acid concentrations before and after secondary fermentation, depending on the type of yeast used (basic wine without secondary fermentation, wine fermented with immobilized yeast, and wine fermented with classical Champagne yeast) and the sugar content of the must (170, 190, and 210 g per liter), and the vintage (2010 and 2011), were evaluated. Concentrations of 20 free amino acids in 18 wine variants were analyzed by ion-exchange liquid chromatography with postcolony ninhydrin derivatization and photometric detection. Results of the study show an increase in all the amino acids represented, except ornithine, after secondary fermentation. The average content of each amino acid in the basic wine, wine fermented with immobilized yeast, and wine fermented with classical Champagne yeast was higher in the variant where classical yeast was used. In this variant, the concentrations of alanine, glutamic acid, lysine, arginine, phenylalanine, valine, and glycine were almost twice as high as in the other variants. A higher proportion of most amino acids was observed in the year 2011; only for amino acids lysine, leucine, phenylalanine, tyrosine, ornithine, histidine, and methionine was a higher concentration observed in the year 2010. A higher concentration of released amino acids was also observed in wine produced from must with a higher sugar content (21° NM). Full article

(This article belongs to the Special Issue Saccharomyces cerevisiae Strains and Fermentation)

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14 pages, 3140 KiB

Open AccessArticle

Kocuria Strains from Unique Radon Spring Water from Jachymov Spa

by Elizaveta Timkina, Lucie Drábová, Andrea Palyzová, Tomáš Řezanka, Olga Maťátková and Irena Kolouchová

Fermentation 2022, 8(1), 35; https://doi.org/10.3390/fermentation8010035 - 16 Jan 2022

Cited by 6 | Viewed by 2862

Abstract

Members of the genus Kocuria are often found in soils contaminated with toxic metals or exposed to high levels of ionizing radiation. The use of classical cultivation technics often leads to the isolation of Kocuria sp. from underground spring waters. These bacterial isolates [...] Read more.

Members of the genus Kocuria are often found in soils contaminated with toxic metals or exposed to high levels of ionizing radiation. The use of classical cultivation technics often leads to the isolation of Kocuria sp. from underground spring waters. These bacterial isolates have to adapt their metabolism to survive in such extreme environments. Four bacterial isolates of the genus Kocuria (Kocuria sp. 101, 208, 301, and 401) were obtained from radon spring water (Jachymov, Czech Republic). These isolates were tested for their ability to withstand stress and extreme conditions. Growth was observed at a temperature range of 10–45 °C with optimal growth temperature between 20 and 30 °C. The content of polyunsaturated fatty acids in all four isolates was proved to be temperature-dependent. The strain Kocuria sp. 301 showed high resistance to all studied extreme conditions (UV radiation, desiccation, and free radicals in medium). The results suggest that isolates from radioactive springs might have developed mechanisms that help them survive under several extreme conditions and could be used in biotechnological production. Full article

(This article belongs to the Special Issue Extremophiles—Source for Novel Biomolecules with Applied Potential)

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11 pages, 1293 KiB

Open AccessArticle

Antioxidant Effect via Bioconversion of Isoflavonoid in Astragalus membranaceus Fermented by Lactiplantibacillus plantarum MG5276 In Vitro and In Vivo

by Ji Yeon Lee, Hye Min Park and Chang-Ho Kang

Fermentation 2022, 8(1), 34; https://doi.org/10.3390/fermentation8010034 - 16 Jan 2022

Cited by 4 | Viewed by 2333

Abstract

In this study, the antioxidant mechanism of Astragalus membranaceus fermented by Lactiplantibacillusplantarum MG5276 (MG5276F-AM) was evaluated in HepG2 cells and in an animal model. HPLC analysis was performed to confirm the bioconversion of the bioactive compounds in A. membranaceus by fermentation. [...] Read more.

In this study, the antioxidant mechanism of Astragalus membranaceus fermented by Lactiplantibacillusplantarum MG5276 (MG5276F-AM) was evaluated in HepG2 cells and in an animal model. HPLC analysis was performed to confirm the bioconversion of the bioactive compounds in A. membranaceus by fermentation. Calycosin and formononetin, which were not detected before fermentation (NF-AM), were detected after fermentation (MG5276F-AM), and its glycoside was not observed in MG5276F-AM. In HepG2 cells, MG5276F-AM alleviated H₂O₂-induced oxidative stress by mediating lipid peroxidation and glutathione levels, and upregulated antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx). In the tBHP-injected mouse model, administration of MG5276F-AM reduced hepatic aspartate transaminase, alanine transaminase, and lipid peroxidation. MG5276F-AM also modulated antioxidant enzymes as well as HepG2 cells. Thus, fermentation of A. membranaceus with L. plantarum MG5276 elevated the isoflavonoid aglycone by hydrolysis of its glycosides, and this bioconversion enhanced antioxidant activity both in vitro and in vivo. Full article

(This article belongs to the Special Issue Fermented Foods and Microbes Related to Health)

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12 pages, 1881 KiB

Open AccessArticle

Metabolomics-Driven Elucidation of Interactions between Saccharomyces cerevisiae and Lactobacillus panis from Chinese Baijiu Fermentation Microbiome

by Yanfeng Liu, Bing Wan, Fan Yang, Xiaolong Zhang, Jianghua Li, Guocheng Du, Li Wang and Jian Chen

Fermentation 2022, 8(1), 33; https://doi.org/10.3390/fermentation8010033 - 14 Jan 2022

Cited by 5 | Viewed by 3390

Abstract

Saccharomyces cerevisiae and Lactobacillus panis are ethanol and lactic acid producers in Maotai-flavor Baijiu fermentation. Understanding their interaction is important to regulate the microbiome composition during fermentation and biosynthesis of ethanol and lactic acid. This study is the first to analyze the interaction [...] Read more.

Saccharomyces cerevisiae and Lactobacillus panis are ethanol and lactic acid producers in Maotai-flavor Baijiu fermentation. Understanding their interaction is important to regulate the microbiome composition during fermentation and biosynthesis of ethanol and lactic acid. This study is the first to analyze the interaction between S. cerevisiae and L. panis at different growth phases during co-cultivation. Results showed that the different growth phases of S. cerevisiae modulated L. panis growth. Metabolomics analysis showed that amino acids and nucleoside secreted by S. cerevisiae promote L. panis growth, while ethanol inhibited L. panis growth. Furthermore, S. cerevisiae modulated L. panis cell growth under varying sugar concentrations. Simulated solid-state fermentation demonstrated that regulating the sugar concentration or the ratio of S. cerevisiae to L. panis could inhibit L. panis cell growth and reduce lactic acid accumulation. This study provided an understanding on Maotai-flavor Baijiu microbiome, which might be useful for metabolite regulation. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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15 pages, 3087 KiB

Open AccessArticle

Improvement of Texture, Nutritional Qualities, and Consumers’ Perceptions of Sorghum-Based Sourdough Bread Made with Pediococcus pentosaceus and Weissella confusa Strains

by Ayoyinka O. Olojede, Abiodun I. Sanni, Kolawole Banwo and Towobola Michael

Fermentation 2022, 8(1), 32; https://doi.org/10.3390/fermentation8010032 - 14 Jan 2022

Cited by 9 | Viewed by 4003

Abstract

Enriched gluten-free products are in high demand owing to increasing celiac disease worldwide. Sourdough fermentation can improve the quality of gluten-free cereals, rendering the resulting product beneficial as a functional food. This study produced sorghum bread (SB) using sourdough technology and evaluated the [...] Read more.

Enriched gluten-free products are in high demand owing to increasing celiac disease worldwide. Sourdough fermentation can improve the quality of gluten-free cereals, rendering the resulting product beneficial as a functional food. This study produced sorghum bread (SB) using sourdough technology and evaluated the texture, nutrition profile, bioactive components, and sensory attributes of the product. The base formula was composed of sorghum flour and corn starch. Sourdough made with Pediococcus pentosaceus LD7 (PL7), P. pentosaceus SA8 (PS8), or Weissella confusa SD8 (WS8) was added at a 20% substitution level for bread production, while bread without sourdough addition was used as the control sample. The texture profiles of the SB were significantly (p ˂ 0.05) softer than that of the control. The sourdough breads possessed higher crude protein, ash, and dietary fibre contents than the control bread. Tannin and total phenol contents were significantly (p ˂ 0.05) higher in the sourdough breads compared to the control sample. The specific volume of the sample made with PS8 sourdough was the highest at 2.50 cm³/g compared to the other samples (2.17–2.46 cm³/g). The sourdough samples had higher scores for taste, texture, aroma, and overall acceptability than the control, with PL7 SB exhibiting the best overall acceptability (6.56). This study established promising use of sourdough with starters as an ingredient for baked products with improved technological and nutritional attributes as well as consumer acceptability. Full article

(This article belongs to the Special Issue Innovations in Sourdough Bread Making)

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19 pages, 7370 KiB

Open AccessArticle

New Malolactic Bacteria Strains Isolated from Wine Microbiota: Characterization and Technological Properties

by Răzvan Vasile Filimon, Claudiu-Ioan Bunea, Ancuța Nechita, Florin Dumitru Bora, Simona Isabela Dunca, Andrei Mocan and Roxana Mihaela Filimon

Fermentation 2022, 8(1), 31; https://doi.org/10.3390/fermentation8010031 - 13 Jan 2022

Cited by 3 | Viewed by 3886

Abstract

Malolactic fermentation (MLF) or biological decrease of wine acidity is defined as the enzymatic bioconversion of malic acid in lactic acid, a process performed by lactic acid bacteria (LAB). The procedures for the isolation of new indigenous LAB strains from the red wines [...] Read more.

Malolactic fermentation (MLF) or biological decrease of wine acidity is defined as the enzymatic bioconversion of malic acid in lactic acid, a process performed by lactic acid bacteria (LAB). The procedures for the isolation of new indigenous LAB strains from the red wines produced in Copou Iasi wine center (NE of Romania) undergoing spontaneous malolactic fermentation, resulted in the obtaining of 67 catalase-negative and Gram-positive LAB strains. After testing in the malolactic fermentative process, application of specific screening procedures and identification (API 50 CH), two bacterial strains belonging to the species Oenococcus oeni (strain 13-7) and Lactobacillus plantarum (strain R1-1) with high yield of malolactic bioconversion, non-producing biogenic amines, and with active extracellular enzymes related to wine aroma, were retained and characterized. Tested in synthetic medium (MRS-TJ) for 10 days, the new isolated LAB strains metabolized over 98% of the malic acid at ethanol concentrations between 10 and 14 % (v/v), low pH (>3.0), total SO₂ doses up to 70 mg/L and temperatures between 15 and 35 °C, showing high potential for future use in the winemaking process as bacterial starter cultures, in order to obtain high quality wines with increased typicity. Full article

(This article belongs to the Special Issue Advances in Wine Fermentation)

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11 pages, 4040 KiB

Open AccessArticle

Aroma Perception of Rose Oxide, Linalool and α-Terpineol Combinations in Gewürztraminer Wine

by Mildred Melina Chigo-Hernandez, Aubrey DuBois and Elizabeth Tomasino

Fermentation 2022, 8(1), 30; https://doi.org/10.3390/fermentation8010030 - 13 Jan 2022

Cited by 10 | Viewed by 3575

Abstract

Cis-Rose oxide was found to be an important chiral compound in Gewürztraminer wine, with an enantiomeric ratio range from 76 to 58%. The enantiomeric ratio showed an important influence on white wine aroma when other monoterpenes were present. The aim of this [...] Read more.

Cis-Rose oxide was found to be an important chiral compound in Gewürztraminer wine, with an enantiomeric ratio range from 76 to 58%. The enantiomeric ratio showed an important influence on white wine aroma when other monoterpenes were present. The aim of this study was to evaluate rose oxide at different ratios and changes to aroma perception, and the interaction of rose oxide with linalool and α-terpineol. A wine model was made based on Gewürztraminer wine. Twelve models were created with different ratios of rose oxide and concentrations of linalool and α-terpineol. Triangle tests, check-all-that-apply (CATA) and descriptive analysis were used to evaluate the aroma of the wines. Results show that the rose oxide ratios of 70:30 and 65:35 were statistically different. Additional descriptive analysis showed that the ratios altered aroma when linalool and α-terpineol were at low and medium concentrations. At high concentrations, linalool and α-terpineol masked any influence from rose oxide. Understanding how monoterpenes alter aroma perception of white wine when at different combinations and concentrations is important to achieving desired wine qualities and helps provide information on how flavor chemistry results can be interpreted without having to run sensory analysis. Full article

(This article belongs to the Special Issue Wine Aromas)

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9 pages, 707 KiB

Open AccessArticle

Antioxidant Activity and Probiotic Properties of Lactic Acid Bacteria

by Seonyoung Kim, Ji Yeon Lee, Yulah Jeong and Chang-Ho Kang

Fermentation 2022, 8(1), 29; https://doi.org/10.3390/fermentation8010029 - 12 Jan 2022

Cited by 41 | Viewed by 7244

Abstract

Oxidative stress, which can cause imbalance in the body by damaging cells and tissues, arises from the immoderate production of reactive oxygen species (ROS)/reactive nitrogen species (RNS). Therefore, external supplements having antioxidant activity are required for reducing oxidative stress. In our study, we [...] Read more.

Oxidative stress, which can cause imbalance in the body by damaging cells and tissues, arises from the immoderate production of reactive oxygen species (ROS)/reactive nitrogen species (RNS). Therefore, external supplements having antioxidant activity are required for reducing oxidative stress. In our study, we investigated DPPH and ABTS radical scavenging ability, and the inhibition effect on the nitric oxide (NO) production of 15 food-derived bacterial strains in LPS-activated RAW264.7 cells. Among these LAB strains, eight strains with an excellent inhibition effect on NO production were selected through comparisons within the same genera. Moreover, the selected strains, including Leuconostoc mesenteroides MG860, Leu. citreum MG210, Pediococcus acidilactici MG5001, P. pentosaceus MG5078, Weissella cibaria MG5090, Levilactobacillus brevis MG5306, Latilactobacillus curvatus MG5020, and Latilactobacillus sakei MG5048 diminished the inducible nitric oxide synthase (iNOS)/cyclooxygenase-2 (COX-2) expression. In addition, the stability and adhesion ability of the eight LAB strains in the gastrointestinal tract were determined. In conclusion, the selected strains have potential as new probiotics with antioxidant effects. Full article

(This article belongs to the Special Issue High Quality Functional Food: Potential of Probiotics)

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19 pages, 3323 KiB

Open AccessArticle

Anaerobic Digestion, Codigestion of Food Waste, and Chicken Dung: Correlation of Kinetic Parameters with Digester Performance and On-Farm Electrical Energy Generation Potential

by Khairina Jaman, Nurjannah Amir, Mohammed Ali Musa, Afifi Zainal, Liyana Yahya, Abdul Malek Abdul Wahab, Sri Suhartini, Tuan Nurfarhana Tuan Mohd Marzuki, Razif Harun and Syazwani Idrus

Fermentation 2022, 8(1), 28; https://doi.org/10.3390/fermentation8010028 - 12 Jan 2022

Cited by 14 | Viewed by 3668

Abstract

Valorization of agro-food waste through anaerobic digestion (AD) is gaining prominence as alternative method of waste minimization and renewable energy production. The aim of this study was to identify the key parameters for digester performance subjected to kinetic study and semicontinuous operation. Biochemical [...] Read more.

Valorization of agro-food waste through anaerobic digestion (AD) is gaining prominence as alternative method of waste minimization and renewable energy production. The aim of this study was to identify the key parameters for digester performance subjected to kinetic study and semicontinuous operation. Biochemical methane potential (BMP) tests were conducted in two different operating conditions: without mixing (WM) and continuous mixing (CM). Three different substrates, including food waste (FW), chicken dung (CD), and codigestion of FW and CD (FWCD) were used. Further kinetic evaluation was performed to identify mixing’s effect on kinetic parameters and correlation of the kinetic parameters with digester performance (volatile solid removal (VS%) and specific methane production (SMP)). The four models applied were: modified Gompertz, logistic, first-order, and Monod. It was found that the CM mode revealed higher values of Rm and k as compared to the WM mode, and the trend was consistently observed in the modified Gompertz model. Nonetheless, the logistic model demonstrated good correlation of kinetic parameters with VS% and SMP. In the continuous systems, the optimum OLR was recorded at 4, 5, and 7 g VS/L/d for FW, CD, and FWCD respectively. Therefore, it was deduced that codigestion significantly improved digester performance. Electrical energy generation at the laboratory scale was 0.002, 0.003, and 0.006 kWh for the FW, CD, and FWCD substrates, respectively. Thus, projected electrical energy generation at the on-farm scale was 372 kWh, 382 kWh, and 518 kWh per day, respectively. Hence, the output could be used as a precursor for large-scale digester-system optimization. Full article

(This article belongs to the Special Issue New Research on Anaerobic Digestion)

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9 pages, 1250 KiB

Open AccessArticle

Difficulties Associated with Small-Scale Production of Carbonic Maceration Wines

by Pilar Santamaría, Lucía González-Arenzana, Rocío Escribano-Viana, Patrocinio Garijo, Rosa López, Susana Sanz and Ana Rosa Gutiérrez

Fermentation 2022, 8(1), 27; https://doi.org/10.3390/fermentation8010027 - 10 Jan 2022

Cited by 6 | Viewed by 1869

Abstract

The aim of the work was to study the vinification by carbonic maceration carried out in small volume tanks, because the use of these deposits is necessary in scientific studies where repetitions are mandatory. For this, vinifications were carried out in 300-kg tanks [...] Read more.

The aim of the work was to study the vinification by carbonic maceration carried out in small volume tanks, because the use of these deposits is necessary in scientific studies where repetitions are mandatory. For this, vinifications were carried out in 300-kg tanks with grapes of the Tempranillo variety. We studied the development of the alcoholic and malolactic fermentations and the microorganisms responsible for them. The results showed an alteration of the wines as a result of the low levels of yeast and the huge bacteria population. This was probably due to the difficulty in maintaining the necessary temperature and anaerobic conditions in the small tanks employed. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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19 pages, 2421 KiB

Open AccessArticle

Immobilization of Aspergillus oryzae DSM 1863 for l-Malic Acid Production

by Aline Kövilein, Vera Aschmann, Silja Hohmann and Katrin Ochsenreither

Fermentation 2022, 8(1), 26; https://doi.org/10.3390/fermentation8010026 - 10 Jan 2022

Cited by 9 | Viewed by 2388

Abstract

Whole-cell immobilization by entrapment in natural polymers can be a tool for morphological control and facilitate biomass retention. In this study, the possibility of immobilizing the filamentous fungus Aspergillus oryzae for l-malic acid production was evaluated with the two carbon sources acetate [...] Read more.

Whole-cell immobilization by entrapment in natural polymers can be a tool for morphological control and facilitate biomass retention. In this study, the possibility of immobilizing the filamentous fungus Aspergillus oryzae for l-malic acid production was evaluated with the two carbon sources acetate and glucose. A. oryzae conidia were entrapped in alginate, agar, and κ-carrageenan and production was monitored in batch processes in shake flasks and 2.5-L bioreactors. With glucose, the malic acid concentration after 144 h of cultivation using immobilized particles was mostly similar to the control with free biomass. In acetate medium, production with immobilized conidia of A. oryzae in shake flasks was delayed and titers were generally lower compared to cultures with free mycelium. While all immobilization matrices were stable in glucose medium, disintegration of bead material and biomass detachment in acetate medium was observed in later stages of the fermentation. Still, immobilization proved advantageous in bioreactor cultivations with acetate and resulted in increased malic acid titers. This study is the first to evaluate immobilization of A. oryzae for malic acid production and describes the potential but also challenges regarding the application of different matrices in glucose and acetate media. Full article

(This article belongs to the Section Fermentation Process Design)

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15 pages, 4818 KiB

Open AccessArticle

Addition of Lactic Acid Bacteria Can Promote the Quality and Feeding Value of Broussonetia papyrifera (Paper Mulberry) Silage

by Wen-Tao Sun, Yuan Huang, Chang-Rong Wu, Chao Peng, Yu-Long Zheng, Chao Chen and Jun Hao

Fermentation 2022, 8(1), 25; https://doi.org/10.3390/fermentation8010025 - 10 Jan 2022

Cited by 9 | Viewed by 1970

Abstract

In this study, the influence of two lactic acid bacteria (LAB) strains [Lactobacillus rhamnosus BDy (LR-BDy) and Lactobacillus buchneri TSy (LB-TSy)] selected from Southwest China on the fermentation characteristics and in vitro gas production of Broussonetia papyrifera (paper mulberry) silage were experimentally [...] Read more.

In this study, the influence of two lactic acid bacteria (LAB) strains [Lactobacillus rhamnosus BDy (LR-BDy) and Lactobacillus buchneri TSy (LB-TSy)] selected from Southwest China on the fermentation characteristics and in vitro gas production of Broussonetia papyrifera (paper mulberry) silage were experimentally explored. The experimental groups were a control group (C), an LB-TSy treatment (LB), an LR-BDy treatment (LR), and an LR-BDy + LB-TSy hybrid group (LR × LB). After the LAB were added, the pH value of paper mulberry silage significantly declined (p < 0.05), and the crude protein content was effectively preserved (p < 0.05). However, no significant changes were found in the levels of neutral detergent fiber, acid detergent fiber, and crude ash (p > 0.05). The lactic acid content in paper mulberry silage was evidently increased (p < 0.05). The in vitro gas production in the LR at 36, 48, and 72 h were markedly higher than that in the other treatments (p < 0.05). Owing to the addition of LAB, the microbial diversity in paper mulberry silage was reduced, while the relative bacterial abundance of Lactobacillus was enhanced. Hence, the addition of LAB selected from the warm and humid region in Southwest China can improve the quality of paper mulberry silage and elevate its feeding value in this region. Full article

(This article belongs to the Special Issue Silage Fermentation)

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14 pages, 3196 KiB

Open AccessEditor’s ChoiceArticle

Effect of Lactobacillus plantarum Inoculation on Chemical Composition, Fermentation, and Bacterial Community Composition of Ensiled Sweet Corn Whole Plant or Stover

by Zhi-Yuan Ma, Emilio Ungerfeld, Zhu Ouyang, Xiao-Ling Zhou, Xue-Feng Han, Yan-Qin Zeng and Zhi-Liang Tan

Fermentation 2022, 8(1), 24; https://doi.org/10.3390/fermentation8010024 - 10 Jan 2022

Cited by 2 | Viewed by 2286

Abstract

Sweet corn is a feed resource with a high content of water-soluble carbohydrates (WSC) available for ruminant production. This study was conducted to investigate the effect of inoculation with Lactobacillus plantarum on fermentation and nutritional quality of sweet corn silage. Sweet corn whole [...] Read more.

Sweet corn is a feed resource with a high content of water-soluble carbohydrates (WSC) available for ruminant production. This study was conducted to investigate the effect of inoculation with Lactobacillus plantarum on fermentation and nutritional quality of sweet corn silage. Sweet corn whole plant (WP) and sweet corn stover (CS) were ensiled in mini silos with or without inoculation of L. plantarum. Proximate composition and fermentation variables, and composition of the bacterial community, were evaluated before ensiling and at the end of the first, second, and third month after ensiling. There was fiber degradation in CS silage after three months of ensilage, but not in WP silage. Inoculation of WP silage, but not of CS silage, with L. plantarum, increased starch content. The relative abundance of genus Lactobacillus was increased by inoculation with L. plantarum by 14.2% and 82.2% in WP and CS silage, respectively. Inoculation with L. plantarum was not necessary to achieve adequate fermentation of either WP or CS silage, as the abundance of native lactic acid bacteria in both materials seemed suitable for adequate fermentation. That said, increased starch content in WP resulting from inoculation with L. plantarum can increase the nutritive value of WP for ruminants. Full article

(This article belongs to the Special Issue Silage Fermentation)

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16 pages, 3070 KiB

Open AccessArticle

Palm Oil Mill Effluent for Lipid Production by the Diatom Thalassiosira pseudonana

by Karthick Murugan Palanisamy, Gaanty Pragas Maniam, Ahmad Ziad Sulaiman, Mohd Hasbi Ab. Rahim, Natanamurugaraj Govindan and Yusuf Chisti

Fermentation 2022, 8(1), 23; https://doi.org/10.3390/fermentation8010023 - 10 Jan 2022

Cited by 6 | Viewed by 2453

Abstract

Biomass and lipid production by the marine centric diatom Thalassiosira pseudonana were characterized in media based on palm oil mill effluent (POME) as a source of key nutrients. The optimal medium comprised 20% by volume POME, 80 µM Na₂SiO₃, [...] Read more.

Biomass and lipid production by the marine centric diatom Thalassiosira pseudonana were characterized in media based on palm oil mill effluent (POME) as a source of key nutrients. The optimal medium comprised 20% by volume POME, 80 µM Na₂SiO₃, and 35 g NaCl L⁻¹ in water at pH ~7.7. In 15-day batch cultures (16:8 h/h light–dark cycle; 200 µmol photons m⁻² s⁻¹, 26 ± 1 °C) bubbled continuously with air mixed with CO₂ (2.5% by vol), the peak concentration of dry biomass was 869 ± 14 mg L⁻¹ corresponding to a productivity of ~58 mg L⁻¹ day⁻¹. The neutral lipid content of the biomass was 46.2 ± 1.1% by dry weight. The main components of the esterified lipids were palmitoleic acid methyl ester (31.6% w/w) and myristic acid methyl ester (16.8% w/w). The final biomass concentration and the lipid content were affected by the light–dark cycle. Continuous (24 h light) illumination at the above-specified irradiance reduced biomass productivity to ~54 mg L⁻¹ day⁻¹ and lipid content to 38.1%. Full article

(This article belongs to the Section Industrial Fermentation)

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14 pages, 1821 KiB

Open AccessArticle

Functional Characterization of Transporters for L-Aspartate in Bacillus licheniformis

by Hanrong Wang, Youran Li, Fengxu Xiao, Yupeng Zhang, Guiyang Shi, Liang Zhang, Sha Xu, Zhongyang Ding and Zhenghua Gu

Fermentation 2022, 8(1), 22; https://doi.org/10.3390/fermentation8010022 - 07 Jan 2022

Cited by 1 | Viewed by 2199

Abstract

Amino acid efflux and influx transport systems play vital roles in industrial microorganisms’ cell growth and metabolism. However, although biochemically characterized, most of them remain unknown at the molecular level in Bacillus licheniformis. In this study, three proteins, namely, YdgF, YvbW [...] Read more.

Amino acid efflux and influx transport systems play vital roles in industrial microorganisms’ cell growth and metabolism. However, although biochemically characterized, most of them remain unknown at the molecular level in Bacillus licheniformis. In this study, three proteins, namely, YdgF, YvbW, and YveA, were predicted to be involved in the active transport of L-aspartate (L-Asp). This was verified by manipulating their encoding genes. When growing in the minimal medium with L-Asp as the only carbon and nitrogen source, the growth of strains lacking proteins YdgF, YvbW, and YveA was significantly inhibited compared with the wild-type strains, while supplementing the expression of the corresponding proteins in the single-gene knockout strains could alleviate the inhibition. Upon overexpression, the recombinant proteins mediated the accumulation of L-aspartate to varying degrees. Compared with the wild-type strains, the single knockout strains of the three protein genes exhibited reduced absorption of L-aspartate. In addition, this study focused on the effects of these three proteins on the absorption of β-alanine, L-glutamate, D-serine, D-alanine, and glycine. Full article

(This article belongs to the Special Issue Microbial Biotransformation by Bacillus)

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18 pages, 1342 KiB

Open AccessArticle

Waste Apple Pomace Conversion to Acrylic Acid: Economic and Potential Environmental Impact Assessments

by Oseweuba Valentine Okoro, Lei Nie, Houman Alimoradi and Amin Shavandi

Fermentation 2022, 8(1), 21; https://doi.org/10.3390/fermentation8010021 - 06 Jan 2022

Cited by 12 | Viewed by 2909

Abstract

The global demand for acrylic acid (AA) is increasing due to its wide range of applications. Due to this growing demand, alternative AA production strategies must be explored to avoid the exacerbation of prevailing climate and global warming issues since current AA production [...] Read more.

The global demand for acrylic acid (AA) is increasing due to its wide range of applications. Due to this growing demand, alternative AA production strategies must be explored to avoid the exacerbation of prevailing climate and global warming issues since current AA production strategies involve fossil resources. Investigations regarding alternative strategies for AA production therefore constitute an important research interest. The present study assesses waste apple pomace (WAP) as a feedstock for sustainable AA production. To undertake this assessment, process models based on two production pathways were designed, modelled and simulated in ASPEN plus^® software. The two competing production pathways investigated included a process incorporating WAP conversion to lactic acid (LA) prior to LA dehydration to generate AA (denoted as the fermentation–dehydration, i.e., FD, pathway) and another process involving WAP conversion to propylene prior to propylene oxidation to generate AA (denoted as the thermochemical–fermentation–oxidation, i.e., TFO, pathway). Economic performance and potential environmental impact of the FD and TFO pathways were assessed using the metrics of minimum selling price (MSP) and potential environmental impacts per h (PEI/h). The study showed that the FD pathway presented an improved economic performance (MSP of AA: USD 1.17 per kg) compared to the economic performance (MSP of AA: USD 1.56 per kg) of the TFO pathway. Crucially, the TFO process was determined to present an improved environmental performance (2.07 kPEI/h) compared to the environmental performance of the FD process (8.72 kPEI/h). These observations suggested that the selection of the preferred AA production pathway or process will require a tradeoff between economic and environmental performance measures via the integration of a multicriteria decision assessment in future work. Full article

(This article belongs to the Section Industrial Fermentation)

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17 pages, 1423 KiB

Open AccessArticle

Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk

by Eleni C. Pappa, Thomas G. Bontinis, John Samelis and Kyriaki Sotirakoglou

Fermentation 2022, 8(1), 20; https://doi.org/10.3390/fermentation8010020 - 04 Jan 2022

Cited by 8 | Viewed by 1841

Abstract

Traditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in freshly fermented Xinotyri cheeses [...] Read more.

Traditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in freshly fermented Xinotyri cheeses (pH 4.5–4.6), regardless of milk pasteurization. Enterobacteria, pseudomonads and staphylococci were suppressed below 6 and 4–5 log CFU/g in fresh cheeses from raw and pasteurized milk, respectively. Salmonella and Listeria spp. were absent in 25 g cheese samples. Coagulase-positive staphylococci exceeded the 5-log safety threshold in fresh raw milk cheeses, which also had 10-fold higher levels of enterococci than pasteurized milk cheeses. Non-LAB groups declined <100 CFU/g, whereas yeasts increased to 5–6 log CFU/g in both cheeses during ripening. Milk pasteurization affected the protein, fat, ash, moisture, nitrogen fractions, total free fatty acids and total free amino acids content of cheeses. Primary proteolysis, detectable by urea-PAGE, was more intense in raw milk cheeses than in pasteurized milk cheeses. However, the hydrophilic and hydrophobic peptides and their ratio in the water-soluble fraction were similar in both cheeses. Cheeses discriminated clearly according to the milk kind (raw, pasteurized) and the stage of ripening, based on the examined biochemical characteristics. Full article

(This article belongs to the Special Issue New Insights into the Application of Lactic Acid Bacteria Strain in the Fermentation)

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12 pages, 992 KiB

Open AccessArticle

Control of Multidrug-Resistant Pathogenic Staphylococci Associated with Vaginal Infection Using Biosurfactants Derived from Potential Probiotic Bacillus Strain

by Najla Haddaji, Karima Ncib, Wael Bahia, Mouna Ghorbel, Nadia Leban, Nouha Bouali, Olfa Bechambi, Ridha Mzoughi and Abdelkarim Mahdhi

Fermentation 2022, 8(1), 19; https://doi.org/10.3390/fermentation8010019 - 01 Jan 2022

Cited by 6 | Viewed by 2143

Abstract

Biosurfactants exhibit antioxidant, antibacterial, antifungal, and antiviral activities. They can be used as therapeutic agents and in the fight against infectious diseases. Moreover, the anti-adhesive properties against several pathogens point to the possibility that they might serve as an anti-adhesive coating agent for [...] Read more.

Biosurfactants exhibit antioxidant, antibacterial, antifungal, and antiviral activities. They can be used as therapeutic agents and in the fight against infectious diseases. Moreover, the anti-adhesive properties against several pathogens point to the possibility that they might serve as an anti-adhesive coating agent for medical inserts and prevent nosocomial infections, without using synthetic substances. In this study, the antimicrobial, antibiofilm, cell surface hydrophobicity, and antioxidative activities of biosurfactant extracted from Bacillus sp., against four pathogenic strains of Staphylococcus spp. associated with vaginal infection, were studied. Our results have shown that the tested biosurfactant possesses a promising antioxidant potential, and an antibacterial potency against multidrug clinical isolates of Staphylococcus, with an inhibitory diameter ranging between 27 and 37 mm, and a bacterial growth inhibition at an MIC of 1 mg/ mL, obtained. The BioSa3 was highly effective on the biofilm formation of different tested pathogenic strains. Following their treatment by BioSa3, a significant decrease in bacterial attachment (p < 0.05) was justified by the reduction in the optical (from 0.709 to 0.111) following their treatment by BioSa3. The antibiofilm effect can be attributed to its ability to alter the membrane physiology of the tested pathogens to cause a significant decrease (p < 0.05) of over 50% of the surface hydrophobicity. Based on the obtained result of the bioactivities in the current study, BioSa3 is a good candidate in new therapeutics to better control multidrug-resistant bacteria and overcome bacterial biofilm-associated infections by protecting surfaces from microbial contamination. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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16 pages, 3267 KiB

Open AccessArticle

Supplementing Glycerol to Inoculum Induces Changes in pH, SCFA Profiles, and Microbiota Composition in In-Vitro Batch Fermentation

by Qingtao Gao, Kai Li, Ruqing Zhong, Cheng Long, Lei Liu, Liang Chen and Hongfu Zhang

Fermentation 2022, 8(1), 18; https://doi.org/10.3390/fermentation8010018 - 31 Dec 2021

Cited by 4 | Viewed by 3001

Abstract

Glycerol was generally added to the inoculum as a cryoprotectant. However, it was also a suitable substrate for microbial fermentation, which may produce more SCFAs, thereby decreased pH of the fermentation broth. This study investigated the effect of supplementing glycerol to inoculum on [...] Read more.

Glycerol was generally added to the inoculum as a cryoprotectant. However, it was also a suitable substrate for microbial fermentation, which may produce more SCFAs, thereby decreased pH of the fermentation broth. This study investigated the effect of supplementing glycerol to inoculum on in vitro fermentation and whether an enhanced buffer capacity of medium could maintain the pH stability during in vitro batch fermentation, subsequently improving the accuracy of short chain fatty acids (SCFAs) determination, especially propionate. Two ileal digesta were fermented by pig fecal inoculum with or without glycerol (served as anti-frozen inoculum or frozen inoculum) in standard buffer or enhanced buffer solution (served as normal or modified medium). Along with the fermentation, adding glycerol decreased the pH of fermentation broth (p < 0.05). However, modified medium could alleviate the pH decrement compared with normal medium (p < 0.05). The concentration of total propionic acid production was much higher than that of other SCFAs in anti-frozen inoculum fermentation at 24 and 36 h, thereby increasing the variation (SD) of net production of propionate. The α-diversity analysis showed that adding glycerol decreased Chao1 and Shannon index under normal medium fermentation (p < 0.05) compared to modified medium (p < 0.05) along with fermentation. PCoA showed that all groups were clustered differently (p < 0.01). Adding glycerol improved the relative abundances of Firmicutes, Anaerovibrio, unclassified_f_Selenomonadaceae, and decreased the relative abundance of Proteobacteria (p < 0.05). The relative abundances of Firmicutes, such as Lactobacillus, Blautia and Eubacterium_Ruminantium_group in modified medium with frozen inoculum fermentation were higher than (p < 0.05) those in normal medium at 36 h of incubation. These results showed that adding glycerol in inoculum changed the fermentation patterns, regardless of substrate and medium, and suggested fermentation using frozen inoculum with modified medium could maintain stability of pH, improve the accuracy of SCFA determination, as well as maintain a balanced microbial community. Full article

(This article belongs to the Special Issue Microbial Metabolism in Fermentation Process)

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18 pages, 4734 KiB

Open AccessArticle

Kinetic Study of Fungal Growth of Several Tanninolytic Strains Using Coffee Pulp Procyanidins

by Leidy Johana Valencia-Hernández, Jorge E. Wong-Paz, Juan Alberto Ascacio-Valdés, Juan Carlos Contreras-Esquivel, Mónica L. Chávez-González, Alaín Martínez-Pérez, Guillermo Castillo-Olvera and Cristóbal N. Aguilar

Fermentation 2022, 8(1), 17; https://doi.org/10.3390/fermentation8010017 - 31 Dec 2021

Cited by 4 | Viewed by 2793

Abstract

Procyanidins are bioactive molecules with industrial and pharmaceutical relevance, they are present in recalcitrant agro-industrial wastes that are difficult to degrade. In this study, we evaluated the potential consumption of procyanidins from Aspergillus niger and Trichoderma harzianum strains in submerged fermentations. For this [...] Read more.

Procyanidins are bioactive molecules with industrial and pharmaceutical relevance, they are present in recalcitrant agro-industrial wastes that are difficult to degrade. In this study, we evaluated the potential consumption of procyanidins from Aspergillus niger and Trichoderma harzianum strains in submerged fermentations. For this purpose, a culture medium containing salts, glucose, and procyanidins was formulated, where procyanidins were added to the medium after the near-total consumption of glucose. The submerged cultures were carried out in amber flasks at 30 °C and 120 rpm. The addition of procyanidins to the culture medium increased the formation of micellar biomass for all the strains used. The use of glucose affected the growth of A. niger GH1 and A. niger HS1, however, in these assays, a total consumption of procyanidins was obtained. These results show that the consumption of procyanidins by fungal strains in submerged fermentations was influenced by the pH, the use of glucose as the first source of carbon, and the delayed addition of procyanidins to the medium. The study showed that A. niger and T. harzianum strains can be used as a natural strategy for the consumption or removal of procyanidins present in recalcitrant residues of risk to the environment and human health. Full article

(This article belongs to the Special Issue Fermentation and Bioactive Metabolites 3.0)

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12 pages, 1213 KiB

Open AccessArticle

Optimization of Propagation Medium for Enhanced Polyhydroxyalkanoate Production by Pseudomonas oleovorans

by Daniela Chmelová, Barbora Legerská, Miroslav Ondrejovič and Stanislav Miertuš

Fermentation 2022, 8(1), 16; https://doi.org/10.3390/fermentation8010016 - 31 Dec 2021

Cited by 6 | Viewed by 2278

Abstract

Polyhydroxyalkanoates (PHAs) represent a promising alternative to commercially used petroleum-based plastics. Pseudomonas oleovorans is a natural producer of medium-chain-length PHA (mcl-PHA) under cultivation conditions with nitrogen limitation and carbon excess. Two-step cultivation appears to be an efficient but more expensive method of PHA [...] Read more.

Polyhydroxyalkanoates (PHAs) represent a promising alternative to commercially used petroleum-based plastics. Pseudomonas oleovorans is a natural producer of medium-chain-length PHA (mcl-PHA) under cultivation conditions with nitrogen limitation and carbon excess. Two-step cultivation appears to be an efficient but more expensive method of PHA production. Therefore, the aim of this work was to prepare a minimal synthetic medium for maximum biomass yield and to optimize selected independent variables by response surface methodology (RSM). The highest biomass yield (1.71 ± 0.04 g/L) was achieved in the optimized medium containing 8.4 g/L glucose, 5.7 g/L sodium ammonium phosphate and 35.4 mM phosphate buffer. Under these conditions, both carbon and nitrogen sources were completely consumed after 48 h of the cultivation and the biomass yield was 1.7-fold higher than in the conventional medium recommended by the literature. This approach demonstrates the possibility of using two-stage PHA cultivation to obtain the maximum amount of biomass and PHA. Full article

(This article belongs to the Section Industrial Fermentation)

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17 pages, 3015 KiB

Open AccessArticle

Performance Evaluation of Pressurized Anaerobic Digestion (PDA) of Raw Compost Leachate

by Alessio Siciliano, Carlo Limonti and Giulia Maria Curcio

Fermentation 2022, 8(1), 15; https://doi.org/10.3390/fermentation8010015 - 30 Dec 2021

Cited by 12 | Viewed by 2188

Abstract

Anaerobic digestion (AD) represents an advantageous solution for the treatment and valorization of organic waste and wastewater. To be suitable for energy purposes, biogas generated in AD must be subjected to proper upgrading treatments aimed at the removal of carbon dioxide and other [...] Read more.

Anaerobic digestion (AD) represents an advantageous solution for the treatment and valorization of organic waste and wastewater. To be suitable for energy purposes, biogas generated in AD must be subjected to proper upgrading treatments aimed at the removal of carbon dioxide and other undesirable gases. Pressurized anaerobic digestion (PDA) has gained increasing interest in recent years, as it allows the generation of a high-quality biogas with a low CO₂ content. However, high pressures can cause some negative impacts on the AD process, which could be accentuated by feedstock characteristics. Until now, few studies have focused on the application of PAD to the treatment of real waste. The present work investigated, for the first time, the performance of the pressurized anaerobic digestion of raw compost leachate. The study was conducted in a lab-scale pressurized CSTR reactor, working in semi-continuous mode. Operating pressures from the atmospheric value to 4 bar were tested at organic loading rate (OLR) values of 20 and 30 kg_COD/m³d. In response to the rise in operating pressure, for both OLR values tested, a decrease of CO₂ content in biogas was observed, whereas the CH₄ fraction increased to values around 75% at 4 bar. Despite this positive effect, the pressure growth caused a decline in COD removal from 88 to 62% in tests with OLR = 20 kg_COD/m³d. At OLR = 30 kg_COD/m³d, an overload condition was observed, which induced abatements of about 56%, regardless of the applied pressure. With both OLR values, biogas productions and specific methane yields decreased largely when the pressure was brought from atmospheric value to just 1 bar. The values went from 0.33 to 0.27 L_CH4/g_CODremoved at 20 kg_COD/m³d, and from 0.27 to 0.18 L_CH4/g_CODremoved at 30 kg_COD/m³d. Therefore, as the pressure increased, although there was an enhanced biogas quality, the overall amount of methane was lowered. The pressured conditions did not cause substantial modification in the characteristics of digestates. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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29 pages, 6597 KiB

Open AccessArticle

The Interactions among Isolates of Lactiplantibacillus plantarum and Dairy Yeast Contaminants: Towards Biocontrol Applications

by Miloslava Kavková, Jaromír Cihlář, Vladimír Dráb, Olga Bazalová and Zuzana Dlouhá

Fermentation 2022, 8(1), 14; https://doi.org/10.3390/fermentation8010014 - 30 Dec 2021

Cited by 3 | Viewed by 1696

Abstract

Yeast diversity in the cheese manufacturing process and in the cheeses themselves includes indispensable species for the production of specific cheeses and undesired species that cause cheese defects and spoilage. The control of yeast contaminants is problematic due to limitations in sanitation methods [...] Read more.

Yeast diversity in the cheese manufacturing process and in the cheeses themselves includes indispensable species for the production of specific cheeses and undesired species that cause cheese defects and spoilage. The control of yeast contaminants is problematic due to limitations in sanitation methods and chemicals used in the food industry. The utilisation of lactic acid bacteria and their antifungal products is intensively studied. Lactiplantibacillus plantarum is one of the most frequently studied species producing a wide spectrum of bioactive by-products. In the present study, twenty strains of L. plantarum from four sources were tested against 25 species of yeast isolated from cheeses, brines, and dairy environments. The functional traits of L. plantarum strains, such as the presence of class 2a bacteriocin and chitinase genes and in vitro production of organic acids, were evaluated. The extracellular production of bioactive peptides and proteins was tested using proteomic methods. Antifungal activity against yeast was screened using in vitro tests. Testing of antifungal activity on artificial media and reconstituted milk showed significant variability within the strains of L. plantarum and its group of origin. Strains from sourdoughs (CCDM 3018, K19-3) and raw cheese (L12, L24, L32) strongly inhibited the highest number of yeast strains on medium with reconstituted milk. These strains showed a consistent spectrum of genes belonging to class 2a bacteriocins, the gene of chitinase and its extracellular product 9 LACO Chitin-binding protein. Strain CCDM 3018 with the spectrum of class 2a bacteriocin gene, chitinase and significant production of lactic acid in all media performed significant antifungal effects in artificial and reconstituted milk-based media. Full article

(This article belongs to the Special Issue Lactic Acid Fermentation and the Colours of Biotechnology 3.0)

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14 pages, 4086 KiB

Open AccessArticle

Mathematical Modelling of Bioethanol Production from Raw Sugar Beet Cossettes in a Horizontal Rotating Tubular Bioreactor

by Mladen Pavlečić, Mario Novak, Antonija Trontel, Nenad Marđetko, Marina Grubišić, Blanka Didak Ljubas, Vlatka Petravić Tominac, Rozelindra Čož Rakovac and Božidar Šantek

Fermentation 2022, 8(1), 13; https://doi.org/10.3390/fermentation8010013 - 30 Dec 2021

Cited by 1 | Viewed by 2454

Abstract

Alternative to the use of fossil fuels are biofuels (e.g., bioethanol, biodiesel and biogas), which are more environmentally friendly and which can be produced from different renewable resources. In this investigation, bioethanol production from raw sugar beet cossettes (semi-solid substrate) by yeast Saccharomyces [...] Read more.

Alternative to the use of fossil fuels are biofuels (e.g., bioethanol, biodiesel and biogas), which are more environmentally friendly and which can be produced from different renewable resources. In this investigation, bioethanol production from raw sugar beet cossettes (semi-solid substrate) by yeast Saccharomyces cerevisiae in a horizontal rotating tubular bioreactor (HRTB) was studied. Obtained results show that HRTB rotation mode (constant or interval) and rotation speed have considerable impact on the efficiency of bioethanol production in the HRTB. The main goal of this research was to develop a non-structural mathematical model of bioethanol production from raw sugar beet cossettes in the HRTB. The established mathematical model of bioethanol production in the HRTB describes substrate utilization and product formation (glycerol, ethanol and acetate) and presumes negative impact of high substrate concentration on the working microorganism (substrate inhibition) by using Andrews inhibition kinetics. All simulations of bioethanol production in the HRTB were performed by using Berkeley Madonna software, version 8.3.14 (Berkeley Madonna, Berkeley, CA, USA). The established non-structural bioprocess model describes relatively well the bioethanol production from raw sugar beet cossettes in the HRTB. Full article

(This article belongs to the Special Issue Ethanol and Value-Added Co-products 3.0)

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13 pages, 2749 KiB

Open AccessArticle

Purification and Characterization of Strong Simultaneous Enzyme Production of Protease and α-Amylase from an Extremophile-Bacillus sp. FW2 and Its Possibility in Food Waste Degradation

by Van Hong Thi Pham, Jaisoo Kim, Jeahong Shim, Soonwoong Chang and Woojin Chung

Fermentation 2022, 8(1), 12; https://doi.org/10.3390/fermentation8010012 - 30 Dec 2021

Cited by 13 | Viewed by 3744

Abstract

Microbial enzymes such as protease and amylase are valuable enzymes with various applications, widely investigated for their applications in degradation of organic waste, biofuel industries, agricultural, pharmaceuticals, chemistry, and biotechnology. In particular, extremophiles play an important role in biorefinery due to their novel [...] Read more.

Microbial enzymes such as protease and amylase are valuable enzymes with various applications, widely investigated for their applications in degradation of organic waste, biofuel industries, agricultural, pharmaceuticals, chemistry, and biotechnology. In particular, extremophiles play an important role in biorefinery due to their novel metabolic products such as high value catalytic enzymes that are active even under harsh environmental conditions. Due to their potentials and very broad activities, this study isolated, investigated, and characterized the protease- and amylase-producing bacterial strain FW2 that was isolated from food waste. Strain FW2 belongs to the genus Bacillus and was found to be closest to Bacillus amyloliquefaciens DSM 7^T with a similarity of 99.86%. This strain was able to degrade organic compounds at temperatures from −6 °C to 75 °C (but weak at 80 °C) under a wide pH range (4.5–12) and high-salinity conditions up to 35% NaCl. Maximum enzyme production was obtained at 1200 ± 23.4 U/mL for protease and 2400 ± 45.8 U/mL for amylase for 4 days at pH 7–7.5, 40–45 °C, and 0–10% NaCl. SDS-PAGE analysis showed that the molecular weights of purified protease were 28 kDa and 44 kDa, corresponding to alkaline protease (AprM) and neutral protease (NprM), respectively, and molecular weight of α-amylase was 55 kDa. Degradation food waste was determined after 15 days, observing a 69% of volume decrease. A potential commercial extremozyme-producing bacteria such as strain FW2 may be a promising contributor to waste degradation under extreme environmental conditions. Full article

(This article belongs to the Special Issue Valorization of Waste from Agro-Food, Food and Marine Industry)

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11 pages, 1606 KiB

Open AccessArticle

Fermentation Condition and Quality Evaluation of Pineapple Fruit Wine

by Antika Boondaeng, Sumaporn Kasemsumran, Kraireuk Ngowsuwan, Pilanee Vaithanomsat, Waraporn Apiwatanapiwat, Chanaporn Trakunjae, Phornphimon Janchai, Sunee Jungtheerapanich and Nanthavut Niyomvong

Fermentation 2022, 8(1), 11; https://doi.org/10.3390/fermentation8010011 - 29 Dec 2021

Cited by 6 | Viewed by 11819

Abstract

This research investigated the impact of the concentration of pineapple juice on the characteristics of pineapple wine during fermentation with Saccharomyces cerevisiae var. burgundy. Three ratios of fresh pineapple juice to water were mixed to obtain three treatments, which were T1—2:1, T2—1:1, [...] Read more.

This research investigated the impact of the concentration of pineapple juice on the characteristics of pineapple wine during fermentation with Saccharomyces cerevisiae var. burgundy. Three ratios of fresh pineapple juice to water were mixed to obtain three treatments, which were T1—2:1, T2—1:1, and T3—1:2. The °Brix and pH of all pineapple juice and water ratios were adjusted to 25 and 4, respectively. The results showed that changes in alcohol, pH, Total Soluble Solids (TSS), Total Titratable Acidity (TAA, as citric acid), and Volatile Acidity (VA, as acetic acid) during the 10-day fermentation among three treatments were significantly different. The highest alcohol content was obtained from the 2:1 with values of 10.71% (v/v). The mixed ratio at 1:1 and 1:2 obtained the alcohol value of 9.61 and 8.35% (v/v), respectively. After ten days of fermentation, TSS, pH values, TAA, and VA were in the range of 9.7–13 °Brix, 3.56–3.82, 0.384–0.448, and 0.0013–0.0016, respectively. However, the appearance, aroma, and taste of all ratios were not significantly different. Sweetness and overall liking, wine with pineapple juice/water ratio at 2:1 had the highest score (p ≤ 0.05). The total antioxidant activities determined by DPPH and total phenolic content were 0.91 mmol/L TE and 365.80 mg/L GAE, respectively, as confirmed by FTIR spectral analyses. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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13 pages, 2537 KiB

Open AccessArticle

Bacterial and Fungal Microbiota of Guinea Grass Silage Shows Various Levels of Acetic Acid Fermentation

by Jianjian Hou and Naoki Nishino

Fermentation 2022, 8(1), 10; https://doi.org/10.3390/fermentation8010010 - 29 Dec 2021

Cited by 5 | Viewed by 2045

Abstract

This study aimed to gain insights into the bacterial and fungal microbiota associated with the acetic acid fermentation of tropical grass silage. Direct-cut (DC, 170 g dry matter [DM]/kg) and wilted (WT, 323 g DM/kg) guinea grass were stored in a laboratory silo [...] Read more.

This study aimed to gain insights into the bacterial and fungal microbiota associated with the acetic acid fermentation of tropical grass silage. Direct-cut (DC, 170 g dry matter [DM]/kg) and wilted (WT, 323 g DM/kg) guinea grass were stored in a laboratory silo at moderate (25 °C) and high (40 °C) temperatures. Bacterial and fungal microbiota were assessed at 3 days, 1 month, and 2 months after ensiling. Lactic acid was the primary fermentation product during the initial ensiling period, and a high Lactococcus abundance (19.7–39.7%) was found in DC silage. After two months, the lactic acid content was reduced to a negligible level, and large amounts of acetic acid, butyric acid, and ethanol were found in the DC silage stored at 25 °C. The lactic acid reduction and acetic acid increase were suppressed in the DC silage stored at 40 °C. Increased abundances of Lactobacillus, Clostridium, and Wallemia, as well as decreased abundances of Saitozyma, Papiliotrema, and Sporobolomyces were observed in DC silages from day three to the end of the 2 month period. Wilting suppressed acid production, and lactic and acetic acids were found at similar levels in WT silages, regardless of the temperature and storage period. The abundance of Lactobacillus (1.72–8.64%) was lower in WT than in DC silages. The unclassified Enterobacteriaceae were the most prevalent bacteria in DC (38.1–64.9%) and WT (50.9–76.3%) silages, and their abundance was negatively related to the acetic acid content. Network analysis indicated that Lactobacillus was involved in enhanced acetic acid fermentation in guinea grass silage. Full article

(This article belongs to the Special Issue Silage Fermentation)

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18 pages, 6803 KiB

Open AccessArticle

Exploitation of Yeasts with Probiotic Traits for Kefir Production: Effectiveness of the Microbial Consortium

by Alice Agarbati, Maurizio Ciani, Laura Canonico, Edoardo Galli and Francesca Comitini

Fermentation 2022, 8(1), 9; https://doi.org/10.3390/fermentation8010009 - 28 Dec 2021

Cited by 12 | Viewed by 2655

Abstract

Kefir is a fermented milk made by beneficial lactic acid bacteria and yeasts inoculated as grains or free cultures. In this work, five yeast strains with probiotic aptitudes belonging to Candida zeylanoides, Yarrowia lipolytica, Kluyveromyces lactis, and Debaryomyces hansenii species [...] Read more.

Kefir is a fermented milk made by beneficial lactic acid bacteria and yeasts inoculated as grains or free cultures. In this work, five yeast strains with probiotic aptitudes belonging to Candida zeylanoides, Yarrowia lipolytica, Kluyveromyces lactis, and Debaryomyces hansenii species were assessed in a defined consortium, in co-culture with a commercial strain of Lactobacillus casei, in order to evaluate the yeasts’ fermentation performance during kefir production, using different milks. The concentration of each yeast was modulated to obtain a stable consortium that was not negatively affected by the bacteria. Furthermore, all yeasts remained viable for five weeks at 4 °C, reaching about 8.00 Log CFU in 150 mL of kefir, a volume corresponding to a pot of a commercial product. The yeasts consortium showed a suitable fermentation performance in all milks, conferring peculiar and distinctive analytical and aromatic properties to the kefirs, confirmed by a pleasant taste. Overall, the panel test revealed that the cow’s and sheep’s kefir were more appreciated than the others; this evaluation was supported by a distinctive fermentation by-products’ content that positively influences the final aroma, conferring to the kefir exalted taste and complexity. These results allow us to propose the yeasts consortium as a versatile and promising multistarter candidate able to affect industrial kefir with both recognizable organoleptic properties and probiotic aptitudes. Full article

(This article belongs to the Special Issue Fermented and Functional Food)

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11 pages, 280 KiB

Open AccessArticle

Mitragyna speciosa Korth Leaves Supplementation on Feed Utilization, Rumen Fermentation Efficiency, Microbial Population, and Methane Production In Vitro

by Kampanat Phesatcha, Burarat Phesatcha, Metha Wanapat and Anusorn Cherdthong

Fermentation 2022, 8(1), 8; https://doi.org/10.3390/fermentation8010008 - 27 Dec 2021

Cited by 9 | Viewed by 2943

Abstract

The objective of the research was to evaluate the different levels of Mitragyna speciosa Korth leaves powder (MSLP) added to rations with 60:40 or 40:60 roughage to a concentrate (R:C ratio) on in vitro nutrient digestibility, rumen fermentation characteristics, microbial population, and methane [...] Read more.

The objective of the research was to evaluate the different levels of Mitragyna speciosa Korth leaves powder (MSLP) added to rations with 60:40 or 40:60 roughage to a concentrate (R:C ratio) on in vitro nutrient digestibility, rumen fermentation characteristics, microbial population, and methane (CH₄) production. The treatments were arranged according to a 2 × 8 factorial arrangement in a completely randomized design. The two factors contain the R:C ratio (60:40 and 40:60) and the levels of MSLP addition (0, 1, 2, 3, 4, 5, 6, and 7% of the total substrate). There was no interaction between the R:C ratio and MSLP supplementation on gas production kinetics, ammonia nitrogen (NH₃-N), and microbial populations. The gas production rate constant for the insoluble fraction (c) was increased by the R:C ratio at (40:60), whilst there was no difference obtained among treatments for cumulative gas production, whilst the gas production rate constant for the insoluble fraction (c) was increased by the R:C ratio at 40:60. The concentration of NH₃-N was influenced by the R:C ratio and MSLP addition both at 4 and 8 h after incubation. In vitro dry matter degradability (IVDMD) and organic matter degradability (IVOMD) were significantly improved by the R:C ratio and supplementation of MSLP at 12 h. Increasing the R:C ratio and MSLP concentrations increased total volatile fatty acid (VFA) and propionic acid (C₃) concentrations while decreasing acetic acid (C₂) and butyric acid (C₄) concentrations; thus, the C₂:C₃ ratio was reduced. MSLP addition reduced protozoa and methanogen populations (p < 0.05). The calculated CH₄ production was decreased (p < 0.05) by the R:C ratios at 40:60 and supplementation of MSLP. Finally, the addition of MSLP as a phytonutrient may improve nutrient degradability and rumen fermentation properties while decreasing protozoa, methanogen population, and CH₄ production. Full article

(This article belongs to the Special Issue Biotransformation of Plant Materials by Molds and Higher Fungi)

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Fermentation, Volume 8, Issue 1 (January 2022) – 37 articles

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