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Fermentation, Volume 10, Issue 6 (June 2024) – 55 articles

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17 pages, 3071 KiB  
Article
Physicochemical Characterization of In Situ Annealed Starch and Its Application in a Fermented Dairy Beverage
by Luma Sarai de Oliveira, Andres David Cordon Cardona, Pedro Henrique Freitas Cardines, Márcio de Barros, Adriana Aparecida Bosso Tomal and Thais de Souza Rocha
Fermentation 2024, 10(6), 321; https://doi.org/10.3390/fermentation10060321 (registering DOI) - 18 Jun 2024
Viewed by 126
Abstract
In this study, the aim was to modify the starches of three different sweet potato varieties—Rosada Uruguaiana (RU), Rosada Canadense (RC), and Ligeirinha (L)—through in situ annealing to increase the content of slowly digestible starch (SDS), which has health benefits. The modified carbohydrate [...] Read more.
In this study, the aim was to modify the starches of three different sweet potato varieties—Rosada Uruguaiana (RU), Rosada Canadense (RC), and Ligeirinha (L)—through in situ annealing to increase the content of slowly digestible starch (SDS), which has health benefits. The modified carbohydrate was then added to a dairy beverage fermented by Lactobacillus casei 1e (L. casei). After annealing, the starches had different physicochemical properties, and the L variety, which had the highest SDS content, was chosen for the formulation of the fermented dairy beverage. Two concentrations of modified starch (7% and 10.5%) were used in the formulations, and a sensory analysis indicated no differences in acceptance and purchase intention. The beverage containing 10.5% modified starch exhibited good physicochemical and microbiological stability. This study demonstrates the possibility of creating a functional fermented dairy beverage with high SDS content, which could potentially benefit consumers’ health. Full article
(This article belongs to the Special Issue Applications of Lactic Acid Bacteria in Fermented Foods and Beverages)
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14 pages, 2924 KiB  
Article
Improvement in Ethylene Glycol Bioconversion to Glycolic Acid by Gluconobacter oxydans Using Central Composite Experimental Design and Bioreactor Fed-Batch Strategies
by Isabella Maria Tenório Soares Santos, Evanildo F. de Souza, Jr., Ricardo Gonzalo Ramirez Brenes, Maria Angela Bernardes Grieco, Ninoska Isabel Bojorge Ramirez and Nei Pereira, Jr.
Fermentation 2024, 10(6), 320; https://doi.org/10.3390/fermentation10060320 - 18 Jun 2024
Viewed by 230
Abstract
This study focuses on optimizing the medium composition for cellular biomass production and bioconversion of ethylene glycol (EG) to glycolic acid (GA) using Gluconobacter oxydans CCT 0552. The improvement in cellular growth in the presence of yeast extract and peptone led to a [...] Read more.
This study focuses on optimizing the medium composition for cellular biomass production and bioconversion of ethylene glycol (EG) to glycolic acid (GA) using Gluconobacter oxydans CCT 0552. The improvement in cellular growth in the presence of yeast extract and peptone led to a 35.7% and 32.7% increase, respectively, compared to the medium with each of these carbon sources separately. Negligible growth was produced when (NH4)2SO4 and urea were used. Optimal bioconversion results were very similar for both the stirred tank and bubble column bioreactors, with GA concentrations reaching 49.4 g/L and 47.7 g/L, volumetric productivities of 0.35 g/L∙h and 0.33 g/L∙h, and product yield factors of 1.08 g/g and 0.94 g/g, respectively. An extended fed-batch strategy using a STR-type bioreactor achieved a concentration of glycolic acid of 94.2 g/L, corresponding to a volumetric productivity of 0.41 g/L∙h and a yield factor of 1.19 g/g. The resulting efficiency of this biological transformation process achieved a remarkable value of 97.3%, simultaneously with a significant decrease in the substrate amount by 90.5%. This study demonstrates the efficiency of G. oxydans in producing GA, offering a cost-effective and environmentally sustainable production method. Full article
(This article belongs to the Special Issue Recent Advances in Bioconversion of Biomass to Value-Added Products)
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15 pages, 1803 KiB  
Article
Metabolic Engineering of Bacillus subtilis for the Production of Poly-γ-glutamic Acid from Glycerol Feedstock
by Lorenzo Pasotti, Ilaria Massaiu, Paolo Magni and Cinzia Calvio
Fermentation 2024, 10(6), 319; https://doi.org/10.3390/fermentation10060319 - 17 Jun 2024
Viewed by 233
Abstract
Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by Bacilli fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. [...] Read more.
Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by Bacilli fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. The abundant glycerol-rich waste generated in the biodiesel industry can be used as a carbon source for γ-PGA production. Here, we studied fermentation performance in different engineered Bacillus subtilis strains in glycerol-based media, considering a swrA+ degU32Hy mutant as the initial producer strain and glucose-based media for comparison. Modifications included engineering the biosynthetic pgs operon regulation (replacing its native promoter with Physpank), precursor accumulation (sucCD or odhAB deletion), and enhanced glutamate racemization (racE overexpression), predicted as crucial reactions by genome-scale model simulations. All interventions increased productivity in glucose-based media, with Physpank-pgssucCD showing the highest γ-PGA titer (52 g/L). Weaker effects were observed in glycerol-based media: ∆sucCD and Physpank-pgs led to slight improvements under low- and high-glutamate conditions, respectively, reaching ~22 g/L γ-PGA (26% increase). No performance decrease was detected by replacing pure glycerol with crude glycerol waste from a biodiesel plant, and by a 30-fold scale-up. These results may be relevant for improving industrial γ-PGA production efficiency and process sustainability using waste feedstock. The performance differences observed between glucose and glycerol media also motivate additional computational and experimental studies to design metabolically optimized strains. Full article
19 pages, 3818 KiB  
Article
Enhancing Freezing Stress Tolerance through Regulation of the Ubiquitin–Proteasome System in Saccharomyces cerevisiae
by Ryoya Tanahashi, Akira Nishimura, Kyoyuki Kan, Natsumi Ishizaki, Shiho Fujishima, Hisanori Endo and Hiroshi Takagi
Fermentation 2024, 10(6), 318; https://doi.org/10.3390/fermentation10060318 - 17 Jun 2024
Viewed by 212
Abstract
The baking industry is experiencing significant growth, primarily due to the widespread adoption of frozen dough baking. However, this process can negatively impact the fermentation ability of yeast, as freezing can induce stress in yeast cells. This study reports the molecular interplay between [...] Read more.
The baking industry is experiencing significant growth, primarily due to the widespread adoption of frozen dough baking. However, this process can negatively impact the fermentation ability of yeast, as freezing can induce stress in yeast cells. This study reports the molecular interplay between the ubiquitin–proteasome system and freezing stress tolerance in the yeast Saccharomyces cerevisiae. Using the proteasome inhibitor MG132, we first screened mutants with enhanced freezing stress tolerance. Three mutants showed elevated activity of the intracellular proteasome, particularly trypsin-like activity (more than threefold) and reduced sensitivity to MG132 inhibition of chymotrypsin-like activity (less than 0.125-fold). Genomic analysis of these mutants revealed mutations in the ROX1 gene, a heme-dependent repressor of hypoxic genes. Importantly, the ROX1 deletion strain displayed slightly improved freezing stress tolerance (about 1.5-fold). Comprehensive transcription analysis identified the ANB1 gene as a potential downstream target of Rox1. Overexpression of ANB1 enhanced freezing stress tolerance (about 1.5-fold) with increased the proteasome’s activity, indicating that Rox1 contributes to changes in the proteasome’s activity and freezing stress tolerance through the function of Anb1. The present data provide new insights into the mechanisms of freezing stress tolerance and help us improve the baking of frozen dough to produce higher-quality bread. Full article
(This article belongs to the Special Issue Advances in Beverages, Food, Yeast and Brewing Research, 3rd Edition)
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18 pages, 8740 KiB  
Article
The Effect of Different Medium Compositions and LAB Strains on Fermentation Volatile Organic Compounds (VOCs) Analysed by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS)
by Sarathadevi Rajendran, Iuliia Khomenko, Patrick Silcock, Emanuela Betta, Michele Pedrotti, Franco Biasioli and Phil Bremer
Fermentation 2024, 10(6), 317; https://doi.org/10.3390/fermentation10060317 - 15 Jun 2024
Viewed by 567
Abstract
Lactic acid bacteria (LAB) fermentation is a viable approach for producing plant-based flavour compounds; however, little is understood about the impact of different LAB strains and medium compositions on the production of volatile organic compounds (VOCs). This study investigated the impact of the [...] Read more.
Lactic acid bacteria (LAB) fermentation is a viable approach for producing plant-based flavour compounds; however, little is understood about the impact of different LAB strains and medium compositions on the production of volatile organic compounds (VOCs). This study investigated the impact of the addition of individual amino acids (AAs) (L-leucine, L-isoleucine, L-phenylalanine, L-glutamic acid, L-aspartic acid, L-threonine, or L-methionine) to a defined medium (DM) on the generation of VOCs (after 0, 7, and 14 days) by one of three LAB strains (Levilactobacillus brevis WLP672 (LB672), Lactiplantibacillus plantarum LP100 (LP100), and Pediococcus pentosaceus PP100 (PP100)), using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS). The concentration of m/z 45.031 (t.i. acetaldehyde) was significantly (p < 0.05) higher after 7 days of fermentation by LP100 in the DM supplemented with threonine compared to all other media fermented by all three strains. The concentrations of m/z 49.012 (t.i. methanethiol) and m/z 95.000 (t.i. dimethyl disulfide) were significantly (p < 0.05) higher after 7 days of fermentation by either LP100, PP100, or LB672 in the DM supplemented with methionine compared to all other media. Information on the role of individual AAs on VOCs generation by different LAB strains will help to guide flavour development from the fermentation of plant-based substrates. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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31 pages, 9619 KiB  
Review
Bacterial Nanocellulose Produced by Cost-Effective and Sustainable Methods and Its Applications: A Review
by Siriporn Taokaew
Fermentation 2024, 10(6), 316; https://doi.org/10.3390/fermentation10060316 - 14 Jun 2024
Viewed by 731
Abstract
This review discusses the recent advancements in cost-effective fermentation methods for producing bacterial nanocellulose (BC) from food and agro-industrial waste. Achieving economical cell culture media is crucial for large-scale BC production, requiring nutrient-rich media at low cost to maximize cellulose yield. Various pretreatment [...] Read more.
This review discusses the recent advancements in cost-effective fermentation methods for producing bacterial nanocellulose (BC) from food and agro-industrial waste. Achieving economical cell culture media is crucial for large-scale BC production, requiring nutrient-rich media at low cost to maximize cellulose yield. Various pretreatment methods, including chemical, physical, and biological approaches, are stated to break down waste into accessible molecules for cellulose-producing bacteria. Additionally, strategies such as dynamic bioreactors and genetic engineering methods are investigated to enhance BC production. This review also focuses on the environmental impact assessment and updated application challenges of BC such as medical applications, energy storage/electronics, filtration membranes, and food packaging. By providing insights from the recent literature findings, this review highlights the innovative potential and challenges in economically and efficiently producing BC from waste streams. Full article
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27 pages, 1771 KiB  
Review
Precision Fermentation as an Alternative to Animal Protein, a Review
by Marilia M. Knychala, Larissa A. Boing, Jaciane L. Ienczak, Débora Trichez and Boris U. Stambuk
Fermentation 2024, 10(6), 315; https://doi.org/10.3390/fermentation10060315 - 14 Jun 2024
Viewed by 602
Abstract
The global food production system faces several challenges, including significant environmental impacts due to traditional agricultural practices. The rising demands of consumers for food products that are safe, healthy, and have animal welfare standards have led to an increased interest in alternative proteins [...] Read more.
The global food production system faces several challenges, including significant environmental impacts due to traditional agricultural practices. The rising demands of consumers for food products that are safe, healthy, and have animal welfare standards have led to an increased interest in alternative proteins and the development of the cellular agriculture field. Within this innovative field, precision fermentation has emerged as a promising technological solution to produce proteins with reduced ecological footprints. This review provides a summary of the environmental impacts related to the current global food production, and explores how precision fermentation can contribute to address these issues. Additionally, we report on the main animal-derived proteins produced by precision fermentation, with a particular focus on those used in the food and nutraceutical industries. The general principles of precision fermentation will be explained, including strain and bioprocess optimization. Examples of efficient recombinant protein production by bacteria and yeasts, such as milk proteins, egg-white proteins, structural and flavoring proteins, will also be addressed, along with case examples of companies producing these recombinant proteins at a commercial scale. Through these examples, we explore how precision fermentation supports sustainable food production and holds the potential for significant innovations in the sector. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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12 pages, 633 KiB  
Article
Effect of Molasses Addition on the Fermentation Quality and Microbial Community during Mixed Microstorage of Seed Pumpkin Peel Residue and Sunflower Stalks
by Ning Zhang, Yajie Zhou, Adnan Ali, Tengyu Wang, Xinfeng Wang and Xinwen Sun
Fermentation 2024, 10(6), 314; https://doi.org/10.3390/fermentation10060314 - 13 Jun 2024
Viewed by 253
Abstract
This study investigated the effect of molasses addition on the fermentation quality, chemical composition, and bacterial community of seed pumpkin peel residue (SPPR) mixed with sunflower straw (SS) in microstorage feed. Molasses additions on a dry matter basis (DM) were divided into three [...] Read more.
This study investigated the effect of molasses addition on the fermentation quality, chemical composition, and bacterial community of seed pumpkin peel residue (SPPR) mixed with sunflower straw (SS) in microstorage feed. Molasses additions on a dry matter basis (DM) were divided into three groups: 0% control (CON), 1% (MA), and 2% (MB), and the raw materials underwent mixed microstorage for a period of 60 days. MA exhibited the highest content of dry matter (DM), the lowest content of neutral detergent fiber (NDF), acid detergent fiber (ADF), and ammoniacal nitrogen (NH3-N), as well as the lowest microbial diversity abundance and the highest relative abundance of lactobacilli (p < 0.05). MB demonstrated the highest crude protein (CP) content and acetic acid (AA) and propionic acid (PA) concentrations, with the lowest pH. In conclusion, the addition of molasses could enhance the quality of mixed microsilage feeds composed of seeded pumpkin peel pomace (SPPR) and sunflower straw (SS), with the optimal addition of molasses being 1% on a DM basis. Full article
(This article belongs to the Section Industrial Fermentation)
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15 pages, 1885 KiB  
Article
Exopolysaccharide Production in Submerged Fermentation of Pleurotus ostreatus under Red and Green Light
by Georgios Bakratsas, Christoforos Tsoumanis, Haralambos Stamatis and Petros Katapodis
Fermentation 2024, 10(6), 313; https://doi.org/10.3390/fermentation10060313 - 13 Jun 2024
Viewed by 344
Abstract
Light controls the developmental, physiological, morphological, and metabolic responses of many fungi. Most fungi respond primarily to blue, red, and green light through their respective photoreceptors. In this study, a screening of different light wavelengths’ effects on submerged Pleurotus ostreatus cultivation in baffled [...] Read more.
Light controls the developmental, physiological, morphological, and metabolic responses of many fungi. Most fungi respond primarily to blue, red, and green light through their respective photoreceptors. In this study, a screening of different light wavelengths’ effects on submerged Pleurotus ostreatus cultivation in baffled flasks was conducted. P. ostreatus growth was not inhibited in all tested conditions, while an equal or higher protein content was observed in comparison with dark conditions. Red and green light favored exopolysaccharide (EPS) production while red and blue light favored intracellular polysaccharide (IPS) production. To focus on EPS production, the effect of red and green light wavelengths on the production of the polysaccharide via submerged cultivation of P. ostreatus LGAM 1123 was tested. Submerged cultivation using red light in baffled flasks resulted in EPS production of 4.1 ± 0.4 g/L and IPS content of 23.1 ± 1.4% of dry weight (dw), while green light resulted in EPS production of 4.1 ± 0.2 g/L and 44.8 ± 5.2% dw IPS content. Similar production levels were achieved in a 3.5 L bioreactor using red light. The EPS produced using red light revealed a polysaccharide with a higher antioxidant activity compared to the polysaccharides produced by green light. In addition, the analysis of the crude polysaccharides has shown differences in biochemical composition. The structural differences and β glucan’s existence in the crude polysaccharides were confirmed by FT-IR analysis. Overall, these polysaccharides could be used in the food industry as they can enhance the functional health-promoting, physicochemical, and sensory properties of food products. Full article
(This article belongs to the Special Issue Innovative Biotechnological Production of Microbial Polysaccharides)
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14 pages, 2498 KiB  
Review
The Role and Application of Redox Potential in Wine Technology
by Marin Berovic
Fermentation 2024, 10(6), 312; https://doi.org/10.3390/fermentation10060312 - 12 Jun 2024
Viewed by 378
Abstract
In wine technology, the on-line measurement of redox potential is a fast, accurate, and reliable measurement that provides insight into the metabolism of Saccharomyces cerevisiae, its microbial activity, and the oxidation and reduction state of wine, as well as insight into its [...] Read more.
In wine technology, the on-line measurement of redox potential is a fast, accurate, and reliable measurement that provides insight into the metabolism of Saccharomyces cerevisiae, its microbial activity, and the oxidation and reduction state of wine, as well as insight into its quality and stability. The significance of the redox potential measurement and control in wine technology as well as the maintenance and regulation of fermentation redox potential using temperature and carbon dioxide fluxes are discussed. Redox potential levels from Eh 100 to 180 mV are typical for non-oxidized wine that is bottling-ready, while levels of Eh 270 to 460 mV represent oxidized wines with typical failures. The relevance of redox potential measurement during the 2-year maturation of Blau Fränkisch wine in 225 L oak barrels at six levels at a temperature 15 °C is presented. The measurement of the redox potential, expressing heterogeneity in redox layers during wine maturation in oak barrels, is represented in various oxido-reductive fermentation zones. On the contrary, the end of the maturation process is indicated by the homogeneity of redox zones, where the matured wine shows no differences in redox measurement on all levels. Using redox potential as a key scale-up criteria ensures comparable and reproducible amounts of the final product even in geometrically non-similar fermenter systems. Full article
(This article belongs to the Special Issue Modeling, Control and Optimization of Wine Fermentation)
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17 pages, 9433 KiB  
Article
Cloning, Expression, Enzymatic Characterization and Mechanistic Studies of M13 Mutant Acetohydroxyacid Synthase That Rescues Valine Feedback Inhibition
by Yaqing Tan, Xingxing Gao, Zhiqiang An, Nan Wang, Yaqian Ma and Hailing Zhang
Fermentation 2024, 10(6), 311; https://doi.org/10.3390/fermentation10060311 - 12 Jun 2024
Viewed by 284
Abstract
Acetohydroxyacid synthase (AHAS) is a key enzyme in the first step of the branched-chain amino acid synthesis pathway, and the production of acetohydroxybutyrate from one molecule of 2-ketobutyric acid and one molecule of pyruvate. AHAS is inhibited by feedback from L-valine, L- [...] Read more.
Acetohydroxyacid synthase (AHAS) is a key enzyme in the first step of the branched-chain amino acid synthesis pathway, and the production of acetohydroxybutyrate from one molecule of 2-ketobutyric acid and one molecule of pyruvate. AHAS is inhibited by feedback from L-valine, L-leucine, and L-isoleucine, and the expression of ilvBN, the gene encoding AHAS, is regulated by all three branched-chain amino acids. A change in amino acids 20–22 on the regulatory subunit (M13 mutation) removes the feedback inhibition by valine. We cloned the gene encoding AHAS (ilvBN) into a vector and then transfected it into Escherichia coli BL21 for expression with targeted changes in amino acids 20–22 on the regulatory subunit, and then determined the activity of the mutated AHAS and its inhibitory effects on valine, isoleucine, and leucine. The enzyme containing the M13 mutation was feedback resistant to all three amino acids. Previous studies have suggested that the binding sites for the three branched-chain amino acids may be at the same variable center. We investigated the enzymatic properties of wild-type and mutant AHAS, modeled their crystal structures, and resolved the mechanism of feedback inhibition induced by mutant M13, which will be useful for continuing the modification of AHAS and the design of broad-spectrum herbicides. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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18 pages, 1927 KiB  
Review
Recent Advances in Resource Utilization of Huangshui from Baijiu Production
by Xiaoying Zhang, Huiwen Zhang, Zhengyi Zhang, Ruixi Wang and Jishi Zhang
Fermentation 2024, 10(6), 310; https://doi.org/10.3390/fermentation10060310 - 12 Jun 2024
Viewed by 359
Abstract
Huangshui is a typical organic wastewater in Chinese Baijiu production, with high pollution and valuable ingredients. Conventional wastewater treatment leads to resource-wasting and environmental pollution. It is urgent that the demand for effective Huangshui treatment with the development of the Baijiu-making industry. This [...] Read more.
Huangshui is a typical organic wastewater in Chinese Baijiu production, with high pollution and valuable ingredients. Conventional wastewater treatment leads to resource-wasting and environmental pollution. It is urgent that the demand for effective Huangshui treatment with the development of the Baijiu-making industry. This review systematically summarizes recent studies, revealing the main characteristics and application of Huangshui, focusing on the application of the rich microbial resources and flavor substances, which provides a practical approach to cascade and full use of Huangshui in medicine, cosmetic, functional food, fertilizer, and wastewater treatment fields. Further research suggested that Huangshui can also be used as an external carbon source for the denitrification system or as an organic liquid water-soluble fertilizer for more fruits and grains. The applications favor improving production efficiency and lowering pollutant emissions and introduce novel concepts for the sustainable development of related industries. Thus, Chinese Baijiu plants can achieve the near-zero emissions of wastewater and cleaner production. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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26 pages, 3610 KiB  
Article
Exploring Phenotype, Genotype, and the Production of Promising GABA Postbiotics by Lactiplantibacillus plantarum: A Comprehensive Investigation
by Heba Abdel-motaal, Amro Abdelazez, Peikun Wang, Ghada Abady, Shaima Abozaed, Bin Ye, Linan Xu, Yuzhong Zhao, Jianrui Niu, Garsa Alshehry, Eman Algarni, Huda Aljumayi and Xinglin Zhang
Fermentation 2024, 10(6), 309; https://doi.org/10.3390/fermentation10060309 - 11 Jun 2024
Viewed by 569
Abstract
This study aims to investigate the probiotic properties of various isolated strains of Lactiplantibacillus plantarum. Specifically, the focus is on examining the expression of the glutamic acid decarboxylase (GAD) gene and its role in the production of gamma-aminobutyric acid (GABA), a promising [...] Read more.
This study aims to investigate the probiotic properties of various isolated strains of Lactiplantibacillus plantarum. Specifically, the focus is on examining the expression of the glutamic acid decarboxylase (GAD) gene and its role in the production of gamma-aminobutyric acid (GABA), a promising postbiotic metabolite. The investigation includes comprehensive analyses of morphology, genetics, resilience against bile, NaCl, and simulated pancreatin juice (SPJ), carbohydrate fermentation patterns, antibacterial activity, susceptibility to antibiotics, and the presence of β-D-galactosidase and GAD enzymes. Six L. plantarum strains exhibited remarkable resilience against bile, NaCl, and SPJ, as well as susceptibility to antibiotics and antagonistic behavior against pathogens. These strains also showed the presence of β-D-galactosidase. Additionally, five L. plantarum strains were found to harbor the gad gene. Further biochemical analysis of four specific L. plantarum strains revealed promising profiles consisting of antibiotics, vitamins, hormones, and a diverse array of metabolites with potential immunotherapeutic properties. This study highlights the substantial potential of Lactiplantibacillus plantarum in generating beneficial postbiotic metabolites. The identified strains offer exciting avenues for further exploration, with potential applications in functional foods and pharmaceuticals. This research opens up possibilities for harnessing the probiotic and postbiotic potential of L. plantarum to develop novel products with health-promoting properties. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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12 pages, 1342 KiB  
Article
Amylolytic Capability and Performance of Probiotic Strains in a Controlled Sorghum Fermentation System
by Seth Molamu Rapoo and Mathoto-Lydia Thaoge-Zwane
Fermentation 2024, 10(6), 308; https://doi.org/10.3390/fermentation10060308 - 11 Jun 2024
Viewed by 343
Abstract
This study aimed to explore the fermentative performance of nine lactic acid bacterial strains with probiotic potential during sorghum fermentation. The strain’s attributes including proliferation counts, pH levels, production of organic acid antibacterial activity, and their ability to break down starch were evaluated [...] Read more.
This study aimed to explore the fermentative performance of nine lactic acid bacterial strains with probiotic potential during sorghum fermentation. The strain’s attributes including proliferation counts, pH levels, production of organic acid antibacterial activity, and their ability to break down starch were evaluated during the fermentation period in the presence and absence of glucose as a carbon source. In addition, the inhibitory activity of these potential probiotic strains against pathogenic bacteria (Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus) was examined through a co-culturing technique. The results demonstrated that all 4 Lactobacillus strains exhibited robust growth in both glucose and glucose-free fermentation experiments. Glucose supplementation significantly enhanced lactic acid yield which ranged from 0.19 to 0.44% compared to fermentation without glucose which ranged from 0.04 to 0.29%. The selected Lactobacillus strains effectively lowered the media pH below 4.0 after 24 h, producing substantial lactic acid. Notably, in the absence of glucose, only Lb. helveticus D7 and Lb. amylolyticus D12 achieved pH levels below 4 after 8 h, producing the highest lactic acid amounts of 0.27 and 0.29% after 24 h, respectively. Amylase activity was detected on two strains, D7 and D12. Furthermore, most of the tested Lactobacillus strains demonstrated complete inhibition (6 log to 0 Log CFU/mL) of pathogen growth after 24 h of co-culturing, suggesting their potential for enhancing the safety quality of sorghum-based fermented products. Full article
(This article belongs to the Special Issue Application of Lactic Acid Bacteria in Fermented Food)
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12 pages, 581 KiB  
Article
Yeast Culture Is Beneficial for Improving the Rumen Fermentation and Promoting the Growth Performance of Goats in Summer
by Shuang Zhang, Yuancong Geng, Yan Ling, Dan Wang and Guixue Hu
Fermentation 2024, 10(6), 307; https://doi.org/10.3390/fermentation10060307 - 8 Jun 2024
Viewed by 310
Abstract
This study aimed to investigate the effects of yeast cultures on the antioxidant capacity, rumen fermentation, and growth performance of goats in the summer. An in vitro experiment was conducted using yeast culture supplemented at 0% (control), 0.6% (test 1), 0.9% (test 2), [...] Read more.
This study aimed to investigate the effects of yeast cultures on the antioxidant capacity, rumen fermentation, and growth performance of goats in the summer. An in vitro experiment was conducted using yeast culture supplemented at 0% (control), 0.6% (test 1), 0.9% (test 2), and 1.2% (test 3) of the dry matter (DM) weight of the basal diet. With a 24 h fermentation, the pH value; the total short-chain fatty acid, acetic acid, propionic acid, and butyric acid concentrations; and the degradability of the DM, the neutral detergent fiber, and the acid detergent fiber were significantly increased (p < 0.05) in tests 2 and 3 compared with the control group. In the feeding experiment, thirty-six crossbreed goats aged 3.0 ± 0.5 months with a body weight of 11.08 ± 1.41 kg were divided, and the yeast culture was supplemented at 0% (control), 0.90% (test 1), and 1.20% (test 2) of the basal diet. Similar effects on rumen fermentation parameters were obtained in test 1 and 2 groups compared to the in vitro experiment. Moreover, the dry matter intake, average daily gain, serum total antioxidant capacity, and the activities of total superoxide dismutase and glutathione peroxidase were significantly higher and the malondialdehyde concentration was significantly lower (p < 0.05) in tests 1 and 2 compared with the control. The results indicated that yeast culture (0.90%) could improve the antioxidant capacity, rumen fermentation, and growth performance of goats in summer. The optimal supplementation concentration is 0.90% DM. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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19 pages, 1409 KiB  
Article
Advancing Thermophilic Anaerobic Digestion of Corn Whole Stillage: Lignocellulose Decomposition and Microbial Community Characterization
by Alnour Bokhary, Fuad Ale Enriquez, Richard Garrison and Birgitte Kiaer Ahring
Fermentation 2024, 10(6), 306; https://doi.org/10.3390/fermentation10060306 - 8 Jun 2024
Viewed by 444
Abstract
Converting corn grains into bioethanol is an expanding practice for sustainable fuel production, but this is accompanied by the production of large quantities of by-products such as whole stillage. In the present study, the influence of advanced wet oxidation and steam explosion (AWOEx) [...] Read more.
Converting corn grains into bioethanol is an expanding practice for sustainable fuel production, but this is accompanied by the production of large quantities of by-products such as whole stillage. In the present study, the influence of advanced wet oxidation and steam explosion (AWOEx) pretreatment on biogas production and lignocellulose decomposition of corn whole stillage (CWS) was evaluated using semi-continuous thermophilic reactors. The digestion of the CWS was shown to be feasible with an organic loading rate (OLR) of 1.12 ± 0.03 kg VS/m3 day and a hydraulic retention time (HRT) of 30 days, achieving a methane yield of 0.75 ± 0.05 L CH4/g VSfed for untreated stillage and 0.86 ± 0.04 L CH4/g VSfed for pretreated stillage, corresponding with an increase in methane yield of about 15%. However, the reactors showed unstable performance with the highest investigated OLRs and shortest HRTs. Under optimal conditions, the conversion efficiencies of COD, cellulose, hemicellulose, and lignin were 88, 95, 97, and 59% for pretreated CWS, and 86, 94, 95, and 51% for untreated CWS, respectively. Microbial community analysis showed that Proteiniphilum, MBA03, and Acetomicrobium were the dominant genera in the digestate and were likely responsible for the conversion of proteins and volatile fatty acids in CWS. Full article
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32 pages, 746 KiB  
Review
A Review of the Production of Hyaluronic Acid in the Context of Its Integration into GBAER-Type Biorefineries
by Guadalupe Pérez-Morales, Héctor Mario Poggi-Varaldo, Teresa Ponce-Noyola, Abigail Pérez-Valdespino, Everardo Curiel-Quesada, Juvencio Galíndez-Mayer, Nora Ruiz-Ordaz and Perla Xochitl Sotelo-Navarro
Fermentation 2024, 10(6), 305; https://doi.org/10.3390/fermentation10060305 - 7 Jun 2024
Viewed by 302
Abstract
Biorefineries (BRFs) that process the organic fraction of municipal solid waste and generate bioproducts and bioenergies have attracted attention because they can simultaneously address energy and environmental problems/needs. The objective of this article was to critically review the microbial production of hyaluronic acid [...] Read more.
Biorefineries (BRFs) that process the organic fraction of municipal solid waste and generate bioproducts and bioenergies have attracted attention because they can simultaneously address energy and environmental problems/needs. The objective of this article was to critically review the microbial production of hyaluronic acid (MPHA) and its production profile for its integration into a GBAER-type BRF (a type of BRF based on organic wastes) and to identify the environmental and economic sustainability aspects of the modified BRF that would confirm it as a sustainable option. It was found that the MPHA by selected strains of pathogenic Streptococci was moderate to high, although the trend to work with genetically transformed (GT) (innocuous) bacteria is gaining momentum. For instance, A GT strain of Corynebacterium glutamicum reached a maximum HA production of 71.4 g L−1. MPHA reports that use organic wastes as sources of carbon (C) and nitrogen (N) are scarce. When alternative sources of C and N were used simultaneously, HA production by S. zooepidemicus was lower than that with conventional sources. We identified several knowledge gaps that must be addressed regarding aspects of process scale-up, HA industrial production, economic feasibility and sustainability, and environmental sustainability of the MPHA. Full article
(This article belongs to the Special Issue Microbial Biorefineries: 2nd Edition)
15 pages, 1534 KiB  
Article
Naturally Colored Ice Creams Enriched with C-Phycocyanin and Spirulina Residual Biomass: Development of a Fermented, Antioxidant, Tasty and Stable Food Product
by Monize Bürck, Camilly Fratelli, Marcelo Assis and Anna Rafaela Cavalcante Braga
Fermentation 2024, 10(6), 304; https://doi.org/10.3390/fermentation10060304 - 7 Jun 2024
Cited by 1 | Viewed by 482
Abstract
Naturally colored fermented foods currently represent the trend toward a global demand for healthier products. This work produced naturally blue and green ice creams using C-phycocyanin (C-PC) and spirulina residual biomass (RB). The ice creams were assessed based on microbiological analysis, color stability [...] Read more.
Naturally colored fermented foods currently represent the trend toward a global demand for healthier products. This work produced naturally blue and green ice creams using C-phycocyanin (C-PC) and spirulina residual biomass (RB). The ice creams were assessed based on microbiological analysis, color stability over 6 months, antioxidant activity before and after in vitro digestion, and sensory evaluation. Considering the microorganisms that must be analyzed in accordance with Brazilian legislation, no growth was detected during the storage period. L*, a*, and b* were maintained according to the expected colors. The blue color was intoned over the shelf life (SC-PC *b −9.46 to −19.44 and MC-PC *b from −9.87 to −18.04). The antioxidant activity of the fermented ice creams SC-PC and SRB increased from 15.4 to 41.3 and from 15.3 to 38.0 µM TE/g, respectively, after bioaccessibility analysis. The C-PC ice cream’s appearance received the highest rating, with 70.26% of volunteers expressing a strong preference, highlighting its attractiveness. However, there were no significant differences compared to control samples in the global acceptance. The RB ice cream presented lower results for flavor but moderate acceptance. Thus, these fermented ice creams presented color stability over 6 months, and their antioxidant activity increased after in vitro digestion, highlighting their biological potential. Full article
(This article belongs to the Special Issue Production and Purification of Microbial Dyes and Pigments)
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16 pages, 1262 KiB  
Article
Assessing the Impact of Commercial Lachancea thermotolerans Immobilized in Biocapsules on Wine Quality: Odor Active Compounds and Organoleptic Properties
by Raquel Muñoz-Castells, Juan Moreno, Teresa García-Martínez, Juan Carlos Mauricio and Jaime Moreno-García
Fermentation 2024, 10(6), 303; https://doi.org/10.3390/fermentation10060303 - 6 Jun 2024
Viewed by 401
Abstract
As a result of climate change, the phenology of grapes has been altered, mainly by increasing the sugar content and decreasing the acidity of ripe grapes. This shift, when the must is fermented, affects the quality of the wine. In this regard, the [...] Read more.
As a result of climate change, the phenology of grapes has been altered, mainly by increasing the sugar content and decreasing the acidity of ripe grapes. This shift, when the must is fermented, affects the quality of the wine. In this regard, the use of selected Saccharomyces and non-Saccharomyces yeasts to mitigate these undesirable effects in wine fermentations entails new strategies to improve their control and also to obtain wines better adapted to current consumer preferences. This work focuses on the use of a commercially available strain of Lachancea thermotolerans immobilized in biological support to form “microbial biocapsules”, comparing its effect with a free format and spontaneous fermentation on alcoholic fermentation and volatile compound composition. These biocapsules, consisting of yeast cells attached to fungal pellets, are being tested to improve wine sensory attributes and also to facilitate yeast inoculation in fermentative and clarification winemaking processes, as well as to reduce time and production costs. The composition of young wines obtained with L. thermotolerans, inoculated as free or biocapsule formats, were compared with those obtained by the traditional method of spontaneous fermentation using native yeast by quantifying 12 oenological variables and the contents in 12 major volatiles, 3 polyols, and 46 minor volatile compounds. The analytical data matrix underwent statistical analysis to compare and establish significant differences at p ≤ 0.05 level between the different wines obtained. Among the major volatiles and polyols, only ethyl acetate, 1,1-diethoxyethane, methanol, 2-methyl-1-butanol, acetoin, ethyl lactate, and glycerol showed significant differences in L. thermotolerans wines. Also, from the minor volatile metabolites, eight showed a significant dependence on the format used for L. thermotolerans, and the other nine volatiles were dependent on both yeast and inoculation format. Only 27 volatiles were selected as aroma-active compounds with odor activity values higher than 0.2 units. Statistical analysis showed a clear separation of the obtained wines into groups when subjected to Principal Component Analysis, and the fingerprinting of wines made with biocapsules shows intermediate values between the two remaining inoculation formats, particularly in the fruity/ripe fruit, green, and floral series. The organoleptic evaluation of wines results in significantly higher values in taste, overall quality, and total score for wines obtained with biocapsules. Full article
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20 pages, 2590 KiB  
Article
The Correlation between Amino Acids and Biogenic Amines in Wines without Added Sulfur Dioxide
by Sorin Macoviciuc, Marius Niculaua, Constantin-Bogdan Nechita, Bogdan-Ionel Cioroiu and Valeriu V. Cotea
Fermentation 2024, 10(6), 302; https://doi.org/10.3390/fermentation10060302 - 6 Jun 2024
Viewed by 305
Abstract
In classical methods of wine production, amino acids play a critical role, as they are fundamental to all types of fermentation. Beyond their consumption in fermentative processes, amino acids undergo several transformations, such as decarboxylation, which produces biogenic amines. These biogenic amines can [...] Read more.
In classical methods of wine production, amino acids play a critical role, as they are fundamental to all types of fermentation. Beyond their consumption in fermentative processes, amino acids undergo several transformations, such as decarboxylation, which produces biogenic amines. These biogenic amines can increase under certain conditions, such as the presence of spoilage bacteria or during malolactic fermentation. Alternative methods of vinification were applied, using sulfur dioxide as a preservative (+SO2) and methods without added sulfites. Alternative methods of vinification were applied using sulfur dioxide as a preservative (+SO2) and methods without added sulfite (−SO2). Monitoring was conducted for Cabernet Sauvignon red (CS), Cabernet Sauvignon rosé (CSR), Fetească regală still (FR), and Fetească regală frizzante (FRF). Alternative procedures employed the use of Pichia kluyveri for its ability to block the oxidation reactions of grapes, malolactic fermentation for all wines without sulfur dioxide (−SO2) to ensure superior stability, and the use of several tannin mixtures to avoid oxidation reactions. Correlations were considered between the amino acids and biogenic amines that have a direct relation through decarboxylation or deamination. The pH of the wines, total acidity, and volatile acidity as principal factors of microbiological wine evolution remained constant. The highest mean concentrations of the detected biogenic amines were putrescine at 23.71 ± 4.82 mg/L (CSRSO2), tyramine at 14.62 ± 1.50 mg/L (FR-SO2), cadaverine at 4.36 ± 1.19 mg/L (CS-SO2), histamine at 2.66 ± 2.19 mg/L (FR + SO2), and spermidine at 9.78 ± 7.19 mg/L (FR + SO2). The wine conditions ensured the inhibition of decarboxylases, but some correlations were found with the corresponding amino acids such as glutamine (r = −0.885, p < 0.05) (CSR-SO2), tyrosine (r = −0,858, p < 0.05) (FR-SO2), lysine (r = −0.906, p < 0.05) (FR-SO2), and histamine (r = −0.987, p < 0.05) (CSR-SO2). Multivariate analysis was performed, and no statistical differences were found between samples with (+SO2) and without added sulfur dioxide (−SO2). The vinification conditions ensured the wines’ stability and preservation and the conditions of producing biogenic amines at the lowest levels in order to not interfere with the olfactive and gustative characteristics. Full article
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7 pages, 274 KiB  
Editorial
Sustainable Development of Food Waste Biorefineries
by José Luis García-Morales and Francisco Jesús Fernández-Morales
Fermentation 2024, 10(6), 301; https://doi.org/10.3390/fermentation10060301 - 5 Jun 2024
Viewed by 303
Abstract
The sustainable development of food waste biorefineries is crucial for a number of reasons, and these reasons have environmental, economic, and social dimensions... Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
32 pages, 980 KiB  
Article
Prefeasibility Analysis of Different Anaerobic Digestion Upgrading Pathways Using Organic Kitchen Food Waste as Raw Material
by Tatiana Agudelo-Patiño, Mariana Ortiz-Sánchez and Carlos Ariel Cardona Alzate
Fermentation 2024, 10(6), 300; https://doi.org/10.3390/fermentation10060300 - 5 Jun 2024
Viewed by 318
Abstract
Anaerobic digestion (AD) is a widely applied technology for renewable energy generation using biogas as energy vector. The existing microbial consortium in this technology allows for the use of several types of biomass as substrates. A promising alternative for the production of high-value [...] Read more.
Anaerobic digestion (AD) is a widely applied technology for renewable energy generation using biogas as energy vector. The existing microbial consortium in this technology allows for the use of several types of biomass as substrates. A promising alternative for the production of high-value products (e.g., mixed volatile fatty acids–VFAs, hydrogen) is the use of modified AD. There are several techniques to achieve this objective by modifying the operating conditions of the process. The literature has described the best AD routes for generating renewable energy or high-value products based on specific substrate types and operating conditions. Few studies have reported the integral fraction valorization of the AD process applying the biorefinery concept. This article provides an analysis of the different routes that favor the production of energy carriers and high-value products involving key issues related to operating conditions and substrates. Moreover, AD is addressed through the biorefinery concept. Finally, a case study is presented where renewable energy and mixed VFAs are generated by applying the biorefinery concept in a number of proposed scenarios using organic kitchen food waste (OKFW) as feedstock. The case study involves an experimental and simulation stage. Then, the economic feasibility of the proposed scenarios is evaluated. In conclusion, AD is a promising and economically feasible technology to produce valuable products from several types of waste materials. Full article
(This article belongs to the Special Issue Biogas and Biochemical Production from Anaerobic Digestion)
30 pages, 743 KiB  
Article
Development of Mass-Conserving Atomistic Mathematical Model for Batch Anaerobic Digestion: Framework and Limitations
by Bhushan P. Gandhi, Alfonso José Lag-Brotons, Lawrence I. Ezemonye, Kirk T. Semple and Alastair D. Martin
Fermentation 2024, 10(6), 299; https://doi.org/10.3390/fermentation10060299 - 5 Jun 2024
Viewed by 336
Abstract
A variety of mathematical models have been developed to simulate the biochemical and physico-chemical aspects of the anaerobic digestion (AD) process to treat organic wastes and generate biogas. However, all these models, including the most widely accepted and implemented Anaerobic Digestion Model No.1, [...] Read more.
A variety of mathematical models have been developed to simulate the biochemical and physico-chemical aspects of the anaerobic digestion (AD) process to treat organic wastes and generate biogas. However, all these models, including the most widely accepted and implemented Anaerobic Digestion Model No.1, remain incapable of adequately representing the material balance of AD and are therefore inherently incapable of material conservation. The absence of robust mass conservation constrains reliable estimates of any kinetic parameters being estimated by regression of empirical data. To address this issue, the present work involved the development of a “framework” for a mass-conserving atomistic mathematical model which is capable of mass conservation, with a relative error in the range of machine precision value and an atom balance with a relative error of ±0.02% whilst obeying the Henry’s law and electroneutrality principle. Implementing the model in an Excel spreadsheet, the study calibrated the model using the empirical data derived from batch studies. Although the model shows high fidelity as assessed via inspection, considering several constraints including the drawbacks of the model and implementation platform, the study also provides a non-exhaustive list of limitations and further scope for development. Full article
(This article belongs to the Special Issue Modeling Methods for Fermentation Processes)
17 pages, 1186 KiB  
Review
The Impact of Physicochemical Conditions on Lactic Acid Bacteria Survival in Food Products
by Barbara Sionek, Aleksandra Szydłowska, Monika Trząskowska and Danuta Kołożyn-Krajewska
Fermentation 2024, 10(6), 298; https://doi.org/10.3390/fermentation10060298 - 4 Jun 2024
Viewed by 366
Abstract
Lactic acid bacteria (LAB), due to their many advantageous features, have been utilized in food manufacturing for centuries. Spontaneous fermentation, in which LAB play a fundamental role, is one of the oldest methods of food preservation. LAB survival and viability in various food [...] Read more.
Lactic acid bacteria (LAB), due to their many advantageous features, have been utilized in food manufacturing for centuries. Spontaneous fermentation, in which LAB play a fundamental role, is one of the oldest methods of food preservation. LAB survival and viability in various food products are of great importance. During technological processes, external physicochemical stressors appear often in combinations. To ensure the survival of LAB, adjustment of optimal physicochemical conditions should be considered. LAB strains should be carefully selected for particular food matrices and the technological processes involved. The LAB’s robustness to different environmental stressors includes different defense mechanisms against stress, including the phenomenon of adaptation, and cross-protection. Recently established positive health effects and influence on human wellbeing have caused LAB to be some of the most desirable microorganisms in the food industry. A good understanding of LAB defense and adaptation mechanisms can lead to both optimization of food production and storage conditions, as well as to obtaining LAB strains with increased tolerance to stressors. Hopefully, as a result, the final food product with naturally present or added LAB can achieve outstanding quality and safety with health benefits that meet consumer expectations. Full article
(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 2nd Edition)
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21 pages, 1323 KiB  
Review
Molecular Markers and Regulatory Networks in Solventogenic Clostridium Species: Metabolic Engineering Conundrum
by Tinuola Olorunsogbon, Christopher Chukwudi Okonkwo and Thaddeus Chukwuemeka Ezeji
Fermentation 2024, 10(6), 297; https://doi.org/10.3390/fermentation10060297 - 4 Jun 2024
Viewed by 320
Abstract
Solventogenic Clostridium species are important for establishing the sustainable industrial bioproduction of fuels and important chemicals such as acetone and butanol. The inherent versatility of these species in substrate utilization and the range of solvents produced during acetone butanol–ethanol (ABE) fermentation make solventogenic [...] Read more.
Solventogenic Clostridium species are important for establishing the sustainable industrial bioproduction of fuels and important chemicals such as acetone and butanol. The inherent versatility of these species in substrate utilization and the range of solvents produced during acetone butanol–ethanol (ABE) fermentation make solventogenic Clostridium an attractive choice for biotechnological applications such as the production of fuels and chemicals. The functional qualities of these microbes have thus been identified to be related to complex regulatory networks that play essential roles in modulating the metabolism of this group of bacteria. Yet, solventogenic Clostridium species still struggle to consistently achieve butanol concentrations exceeding 20 g/L in batch fermentation, primarily due to the toxic effects of butanol on the culture. Genomes of solventogenic Clostridium species have a relatively greater prevalence of genes that are intricately controlled by various regulatory molecules than most other species. Consequently, the use of genetic or metabolic engineering strategies that do not consider the underlying regulatory mechanisms will not be effective. Several regulatory factors involved in substrate uptake/utilization, sporulation, solvent production, and stress responses (Carbon Catabolite Protein A, Spo0A, AbrB, Rex, CsrA) have been identified and characterized. In this review, the focus is on newly identified regulatory factors in solventogenic Clostridium species, the interaction of these factors with previously identified molecules, and potential implications for substrate utilization, solvent production, and resistance/tolerance to lignocellulose-derived microbial inhibitory compounds. Taken together, this review is anticipated to highlight the challenges impeding the re-industrialization of ABE fermentation, and inspire researchers to generate innovative strategies for overcoming these obstacles. Full article
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16 pages, 3008 KiB  
Article
Enhancing Biohydrogen Production: The Role of Iron-Based Nanoparticles in Continuous Lactate-Driven Dark Fermentation of Powdered Cheese Whey
by Deborah Leroy-Freitas, Raúl Muñoz, Leonardo J. Martínez-Mendoza, Cristina Martínez-Fraile and Octavio García-Depraect
Fermentation 2024, 10(6), 296; https://doi.org/10.3390/fermentation10060296 - 3 Jun 2024
Viewed by 326
Abstract
Here, a comprehensive investigation was conducted under various operational strategies aimed at enhancing biohydrogen production via dark fermentation, with a specific focus on the lactate metabolic pathway, using powdered cheese whey as a substrate. Initially, a batch configuration was tested to determine both [...] Read more.
Here, a comprehensive investigation was conducted under various operational strategies aimed at enhancing biohydrogen production via dark fermentation, with a specific focus on the lactate metabolic pathway, using powdered cheese whey as a substrate. Initially, a batch configuration was tested to determine both the maximum hydrogen yield (100.2 ± 4.2 NmL H2/g CODfed) and the substrate (total carbohydrates) consumption efficiency (94.4 ± 0.8%). Subsequently, a transition to continuous operation was made by testing five different operational phases: control (I), incorporation of an inert support medium for biomass fixation (II), addition of carbon-coated, zero-valent iron nanoparticles (CC-nZVI NPs) at 100 mg/L (III), and supplementation of Fe2O3 nanoparticles at concentrations of 100 mg/L (IV) and 300 mg/L (V). The results emphasized the critical role of the support medium in stabilizing the continuous system. On the other hand, a remarkable increase of 10% in hydrogen productivity was observed with the addition of Fe2O3 NPs (300 mg/L). The analysis of the organic acids’ composition unveiled a positive correlation between high butyrate concentrations and improved volumetric hydrogen production rates (25 L H2/L-d). Moreover, the presence of iron-based NPs effectively regulated the lactate concentration, maintaining it at low levels. Further exploration of the bacterial community dynamics revealed a mutually beneficial interaction between lactic acid bacteria (LAB) and hydrogen-producing bacteria (HPB) throughout the experimental process, with Prevotella, Clostridium, and Lactobacillus emerging as the predominant genera. In conclusion, this study highlighted the promising potential of nanoparticle addition as a tool for boosting biohydrogen productivity via lactate-driven dark fermentation. Full article
(This article belongs to the Special Issue Fermentative Biohydrogen Production)
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23 pages, 1184 KiB  
Article
Improved Antioxidant Properties and Vitamin C and B12 Content from Enrichment of Kombucha with Jujube (Ziziphus jujuba Mill.) Powder
by Chiara La Torre, Pierluigi Plastina, Erika Cione, Argyro Bekatorou, Theano Petsi and Alessia Fazio
Fermentation 2024, 10(6), 295; https://doi.org/10.3390/fermentation10060295 - 2 Jun 2024
Viewed by 316
Abstract
(1) Objectives: Traditional kombucha (K) is a fermented beverage obtained from black or green tea infusion. Besides traditional substrates, the possibility of using alternative ingredients resulted in changes in metabolic profile and biological activity. The aim of this work was to study an [...] Read more.
(1) Objectives: Traditional kombucha (K) is a fermented beverage obtained from black or green tea infusion. Besides traditional substrates, the possibility of using alternative ingredients resulted in changes in metabolic profile and biological activity. The aim of this work was to study an alternative kombucha (KJ) prepared by the addition of jujube powder to black tea. (2) Materials and Methods: Changes in pH, protein, sugars, phenolic (TPC), flavonoid (TFC), and vitamin C and B12 content were evaluated at different time points over a period of 45 days. The identification of polyphenols by HPLC DAD and the antioxidant capacity by DPPH, ABTS, and FRAP tests of all samples was also carried out. (3) Results: The results showed higher protein, total phenolic content, and antioxidant capacity in KJ samples than in K ones. Vitamin C content increased during fermentation and reached its maximum concentration on day 45 (7.1 ± 0.3 mg/100 mL) for KJ. Caffeine in the supplemented samples was the main biocompound among those identified. Vitamin B12 formed on day 4 in K and after 24 h in KJ samples, remaining constant at the initial value of 2.30 ± 0.01 mg/100 mL up to day 45. (4) Conclusions: The results highlight that the fortification of kombucha with jujubes improved its biological activity and the content of bioactive compounds. Full article
(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 2nd Edition)
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14 pages, 12940 KiB  
Article
Exploring the Potential Lipid-Lowering and Weight-Reducing Mechanisms of FH06 Fermented Beverages Based on Non-Targeted Metabolomics and Network Pharmacology
by Haoming Wang, Ting Wang, Jinghan Wang, Ronghan Liu, Yingying Cui, Xiurong Wu, Rui Dai, Yanglin Wu, Xiangzhen Nie, Xiantao Yan and Ruixia Gu
Fermentation 2024, 10(6), 294; https://doi.org/10.3390/fermentation10060294 - 2 Jun 2024
Viewed by 239
Abstract
Investigating the intricate pathways through which FH06 fermentation broth exerts lipid-lowering and weight-loss effects is pivotal for advancing our comprehension of metabolic regulation and therapeutic interventions. Ultrahigh-performance liquid chromatography quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-QE-MS) detection and the ChEMBL database were [...] Read more.
Investigating the intricate pathways through which FH06 fermentation broth exerts lipid-lowering and weight-loss effects is pivotal for advancing our comprehension of metabolic regulation and therapeutic interventions. Ultrahigh-performance liquid chromatography quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-QE-MS) detection and the ChEMBL database were used to determine the effective compounds in the FH06 fermentation broth and predict their targets. The TTD database and DisGeNET database were used to query obesity-related targets. The STRING database was used to construct protein interaction information. The Gene Ontology (GO) database and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to perform biological function annotation (GO) and KEGG pathway enrichment analyses of the targets. Results: A total of 85 effective compounds were screened from the fermentation broth of FH06; these compounds may act on TP53, PPARG, TNF, and other targets through 10 signaling pathways, such as the chemical carcinogenesis-receptor activation and lipid and atherosclerosis pathways, and exert pharmacological effects, such as hypoglycemic effects and weight loss. They also have anti-inflammatory, antioxidant, antitumor, and immunoregulatory effects. These findings reveal the active ingredients of FH06 fermentation broth and its multi-target and multi-channel characteristics in lipid lowering and weight loss. This study has positive implications for the clinical treatment of obesity using FH06, providing a theoretical and scientific basis for further developing of FH06-assisted lipid-lowering products. Full article
(This article belongs to the Special Issue Nutrition and Health of Fermented Foods, 3rd Edition)
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13 pages, 1738 KiB  
Article
Microbial Characterisation of a Two-Stage Anaerobic Digestion Process for Conversion of Agri-Based Feedstock in Biogas and Long-Chain Fatty Acids in a Circular Economy Framework
by Elisabetta Fanfoni, Erika Sinisgalli, Alessandra Fontana, Mariangela Soldano, Mirco Garuti and Lorenzo Morelli
Fermentation 2024, 10(6), 293; https://doi.org/10.3390/fermentation10060293 - 31 May 2024
Viewed by 239
Abstract
In addition to energy recovery, the anaerobic digestion of agro-industrial byproducts can also produce different high-value-added compounds. Two-stage and single-stage reactors were compared for microbial communities’ selection and long-chain fatty acid (LCFA) accumulation to investigate which microbial genera are most linked to the [...] Read more.
In addition to energy recovery, the anaerobic digestion of agro-industrial byproducts can also produce different high-value-added compounds. Two-stage and single-stage reactors were compared for microbial communities’ selection and long-chain fatty acid (LCFA) accumulation to investigate which microbial genera are most linked to the production of these compounds. The microbial communities present in the two reactors’ configuration in the steady state were characterised by 16S rRNA amplicon sequencing, while LCFAs were extracted and quantified from digestate samples by gas chromatography. The results showed the differentiation of the microbially dominant families in the two setups: Defluviitaleaceae and Clostridiaceae in the acidogenic and methanogenic reactor of the two-stage reaction respectively, while Dysgonomonadaceae in the single-stage set-up. LCFA accumulation was significantly detected only in the acidogenic reactor, with palmitic (2764 mg/kg), linoleic (1795 mg/kg) and stearic (1751 mg/kg) acids as the most abundant. The dominance of Defluviitaleaceae UCG 011, along with the low abundance of the LCFA oxidiser Syntrophomonas spp. in the acidogenic reactor, could be linked to the accumulation of such compounds. Therefore, the different microbial communities shaped by the two reactors’ configuration affected the accumulation of LCFAs, indicating that the two-stage anaerobic digestion of agro-industrial byproducts was more effective than single-stage digestion. Full article
(This article belongs to the Section Industrial Fermentation)
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17 pages, 3631 KiB  
Article
Identifying a Role of Polysaccharides from Agaricus Blazei Murill in Combating Skin Photoaging: The Effect of Antioxidants on Fibroblast Behavior
by Feiqian Di, Wenjing Cheng, Luyao Li, Chunhong Pu, Ruiliang Sun, Jiachan Zhang, Changtao Wang and Meng Li
Fermentation 2024, 10(6), 292; https://doi.org/10.3390/fermentation10060292 - 30 May 2024
Viewed by 174
Abstract
Irradiation with ultraviolet A (UVA) plays an important role in the pathogenesis of skin photoaging since it increases oxidative stress and inflammation in the epidermis. There is an urgent need to screen, investigate, and apply the potential anti-photoaging active ingredients. Agaricus blazei Murill [...] Read more.
Irradiation with ultraviolet A (UVA) plays an important role in the pathogenesis of skin photoaging since it increases oxidative stress and inflammation in the epidermis. There is an urgent need to screen, investigate, and apply the potential anti-photoaging active ingredients. Agaricus blazei Murill (ABM) polysaccharides have a wide range of promising pharmacological applications. Previous studies have confirmed their antioxidant effect, but whether it has an anti-photoaging effect is unclear. In this study, two ABM polysaccharides (AB-J and AB-K) were obtained to discuss the potential photodamage-protective capacity. The free radical scavenging abilities in vitro, the safety assessment, and their protective effects and mechanisms on UVA-induced human fibroblasts (HSFs) were evaluated. The intracellular antioxidant enzyme levels and extracellular matrix proteins, such as COL-I and ELN, were significantly accelerated, and metalloproteinases (MMP-1, and MMP-9) were decreased by AB-J and AB-K. The Keap-1-Nrf2/ARE signaling pathway was activated, thus inducing the upregulated expression of downstream genes (Ho-1 and Nqo-1). The suppression of P38 and Jnk1 by AB-J and AB-K was speculated to be the inducer of the activation of the Keap-1-Nrf2/ARE signaling pathway. Owing to the excellent exhibition of AB-J, its safety assessment and the structural characterization are discussed further. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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