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Fermentation, Volume 8, Issue 11 (November 2022) – 92 articles

Cover Story (view full-size image): Raw milk is a complex environment characterized by a rich microbiota whose composition can be influenced by several factors, including the ruminant feeding strategies. Milk characteristics and natural microbiota play a key role during ripening, influencing the development of the flavor and organoleptic properties of Pecorino cheeses, but also the accumulation of undesirable substances, such as biogenic amines. The results of the present research indicate that animal feeding with grape pomace affects the complex microbiota of cheese made with raw ewes’ milk. The changes in cheese microbiota influence the development of different volatile organic compounds with a possible impact on cheese aroma and taste. However, the presence of cadaverine and putrescine may prejudice cheese safety. View this paper
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15 pages, 1673 KiB  
Article
Nipa Sap Can Be Both Carbon and Nutrient Source for Acetic Acid Production by Moorella thermoacetica (f. Clostridium thermoaceticum) and Reduced Minimal Media Supplements
by Dung Van Nguyen and Harifara Rabemanolontsoa
Fermentation 2022, 8(11), 663; https://doi.org/10.3390/fermentation8110663 - 21 Nov 2022
Cited by 1 | Viewed by 2409
Abstract
Nipa sap is an excellent microbial nutrient and carbon source since it contains essential minerals and vitamins, in addition to sugars. In this study, nipa sap was successfully fermented to acetic acid by the industrially important Moorella thermoacetica without additional trace metals, without [...] Read more.
Nipa sap is an excellent microbial nutrient and carbon source since it contains essential minerals and vitamins, in addition to sugars. In this study, nipa sap was successfully fermented to acetic acid by the industrially important Moorella thermoacetica without additional trace metals, without inorganics, or without yeast extract. Although microbial growth kinetics differed from one nutrient condition to another, acetic acid concentrations obtained without trace metals, without inorganics, and without yeast extract supplements were in the same range as that with full nutrient, confirming that nipa sap is a good nutrient source for M. thermoacetica. Fermentations in vials and fermenters showed comparable acetic acid production trends but acetic acid concentrations were higher in fermenters. Upon economic analysis, it was found that the most profitable nutrient condition was without yeast extract. It reduced the cost of culture medium from $1.7 to only $0.3/L, given that yeast extract costs $281/kg, while nipa sap can be available from $0.08/kg. Minimal medium instead of the traditional complex nutrient simplifies the process. This work also opens opportunities for profitable anaerobic co-digestion and co-fermentation of nipa sap with other biomass resources where nipa sap will serve as an inexpensive nutrient source and substrate. Full article
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17 pages, 1787 KiB  
Review
Unveiling the Microbial Ecology behind Mezcal: A Spirit Drink with a Growing Global Demand
by Patricia Alejandra Becerra-Lucio, Elia Diego-García, Karina Guillén-Navarro and Yuri Jorge Peña-Ramírez
Fermentation 2022, 8(11), 662; https://doi.org/10.3390/fermentation8110662 - 21 Nov 2022
Cited by 2 | Viewed by 4046
Abstract
The advent of omics has expanded our knowledge of microbial ecology behind Mezcal, a fermented spirit made from the juices of cooked Agave plants (Agave spp., Asparagaceae). Mezcal has been produced in Mexico for over 200 years, however, has been in high [...] Read more.
The advent of omics has expanded our knowledge of microbial ecology behind Mezcal, a fermented spirit made from the juices of cooked Agave plants (Agave spp., Asparagaceae). Mezcal has been produced in Mexico for over 200 years, however, has been in high demand since its discovery by international markets in the last decade. Mezcal is appreciated for its diverse and complex sensory profile, which is tied to the geographic and environmental diversity of the different Mezcal-producing regions. This regional typicity is brought about by spontaneous fermentation consortia that act in loosely controlled artisanal fermentation processes. Previous works have mainly concentrated on microorganisms involved in the biosynthesis of alcohol and other volatile compounds, or from a different perspective, on culturable microorganisms (mainly yeasts) influencing the taste profile. Attention has been aimed at the richness of microbial populations in point events or under laboratory conditions, which leaves much of the biological richness out of account. Omics techniques have become powerful tools for characterizing the composition of autochthonous fermentation microbiota, regional or endemic features, and ecological processes that determine the dynamics of Mezcal fermentation. The analyses of genetic material, proteins, and metabolites allow disentangling the biological complexity of Mezcal production. This review presents the reader with an up-to-date overview of publications that discuss microbial communities in Mezcal fermentation, metabolic pathways regulated by microbial interactions, and the application of omics to characterize the spontaneous fermenting microbiota conformation and dynamics considering the subjacent ecological processes. Full article
(This article belongs to the Special Issue Research Advances in Fermented Beverages)
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15 pages, 3490 KiB  
Article
Efficient Corncob Biorefinery for Ethanol Initiated by a Novel Pretreatment of Densifying Lignocellulosic Biomass with Sulfuric Acid
by Shuangmei Liu, Yang Yu, Zhaoxian Xu, Sitong Chen, Guannan Shen, Xinchuan Yuan, Qiufeng Deng, Wenyuan Shen, Shizhong Yang, Chengcheng Zhang, Xiangxue Chen and Mingjie Jin
Fermentation 2022, 8(11), 661; https://doi.org/10.3390/fermentation8110661 - 21 Nov 2022
Cited by 13 | Viewed by 2491
Abstract
Corncob is a potential feedstock for biorefineries to produce cellulosic ethanol and other chemicals. Densifying lignocellulosic biomass with chemicals followed by autoclave (DLCA) has been confirmed an efficient and economical pretreatment method, and it was applied in the present work for conversion of [...] Read more.
Corncob is a potential feedstock for biorefineries to produce cellulosic ethanol and other chemicals. Densifying lignocellulosic biomass with chemicals followed by autoclave (DLCA) has been confirmed an efficient and economical pretreatment method, and it was applied in the present work for conversion of corncob to bioethanol. The dosage of sulfuric acid, solid loading of biomass, and autoclave time for pretreatment were investigated. Enzymatic hydrolysis at 25–35% solids loadings resulted in 91–97% sugar conversions. Fermentation of the resulted hydrolysates went well with the highest ethanol titer reaching 75.71 g/L at 35% solid loading. Simultaneous saccharification and co-fermentation was applied to further improve xylose consumption at high solids loadings and the ethanol titer was enhanced to 82.0 g/L at 35% solid loading with an ethanol yield of 21.67 kg/100 kg corncob. This study demonstrated DLCA provided a highly digestible and highly fermentable corncob for biorefinery. Full article
(This article belongs to the Special Issue Biorefinery of Lignocellulosic Biomass)
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16 pages, 3065 KiB  
Article
Effects of Different Additives on Fermentation Quality, Microbial Communities, and Rumen Degradation of Alfalfa Silage
by Wenqing Ling, Lei Zhang, Qixian Feng, Abraham Allan Degen, Jue Li, Yue Qi, Yan Li, Yi Zhou, Yijia Liu, Fulin Yang and Jing Zhou
Fermentation 2022, 8(11), 660; https://doi.org/10.3390/fermentation8110660 - 21 Nov 2022
Cited by 4 | Viewed by 2500
Abstract
This study examined the effects of different additives on the fermentation quality, nutrient composition, microbial communities, and rumen degradation of ensiled alfalfa. Six treatments were employed in which additives were applied to alfalfa on a fresh weight basis: CK (no additive), FA (0.6% [...] Read more.
This study examined the effects of different additives on the fermentation quality, nutrient composition, microbial communities, and rumen degradation of ensiled alfalfa. Six treatments were employed in which additives were applied to alfalfa on a fresh weight basis: CK (no additive), FA (0.6% formic acid), CaO (3% calcium oxide and 3% urea), LB (1 × 106 cfu/g Lentilactobacillus buchneri), GLB (2% glucose and 1 × 106 cfu/g L. buchneri), and FLB (2% fucoidan and 1 × 106 cfu/g L. buchneri). After 60 days of ensiling, all treatments altered the bacterial communities, improved the fermentation quality, reduced dry matter (DM) and crude protein (CP) losses, and enhanced the rumen degradation of nutrients. The addition of LB increased the relative abundance of Lactobacillus spp. (p < 0.05), whereas GLB reduced (p < 0.05) the NH3-N:TN ratio and elevated (p < 0.05) the concentrations of Lactobacillus and lactic acid content. The FA treatment reduced (p < 0.05) the pH, as well as the DM and CP degradations, while the CaO treatment increased the degradations of DM, acid detergent fiber, and neutral detergent fiber. We concluded that FA, LB, GLB, and FLB had beneficial effects on alfalfa fermentation, and that CaO increased alfalfa silage rumen degradation. Full article
(This article belongs to the Special Issue Study of the Microbial Populations on Silage and Hay Quality)
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14 pages, 4651 KiB  
Article
Sustainable Production and Characteristics of Dried Fermented Vegetables
by Emilia Janiszewska-Turak, Katarzyna Rybak, Katarzyna Pobiega, Anna Nikodem and Anna Gramza-Michałowska
Fermentation 2022, 8(11), 659; https://doi.org/10.3390/fermentation8110659 - 21 Nov 2022
Cited by 3 | Viewed by 3119
Abstract
The current fashion for healthy food and the increasing number of people with lactose intolerance make fermented vegetables increasingly important. On top of this, surpluses unused in the vegetable harvest can become a potential source of “green waste”. The use of fermentation and [...] Read more.
The current fashion for healthy food and the increasing number of people with lactose intolerance make fermented vegetables increasingly important. On top of this, surpluses unused in the vegetable harvest can become a potential source of “green waste”. The use of fermentation and freeze-drying can result in a valuable, sustainable product that can solve the problems of spoiled vegetables and the need for refrigerated storage. Therefore, this study aimed to obtain sustainable dried fermented vegetables and to compare their selected physical and structural properties. Beetroot, carrot, and red pepper were selected for this purpose. These vegetables were subjected to a spontaneous lactic fermentation process. After the process, the vegetables were freeze-dried, and their structure and selected properties (color, dry weight, and the number of lactic acid bacteria) were determined. Fermented vegetables were found to differ from their raw sources in structure and color, the main discrepancies being shown by the b* factor (yellow-blue). Root vegetables had smaller pores of structure in the freeze-dried samples than red peppers. The freeze-drying process did not affect the number of bacteria. It can be concluded that both the fermentation and the freeze-drying processes affected the structure of the selected vegetables. All tested vegetables can be fermented and freeze-dried without major changes in color and microbiological properties and can be used as a potential source of lactic acid bacteria and health-promoting pigments, e.g., in the form of chips. In addition, their shelf life is extended. Full article
(This article belongs to the Special Issue Food Wastes: Feedstock for Value-Added Products: 4th Edition)
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17 pages, 5353 KiB  
Article
Removal of Nutrients by Using Green Microalgae from Lab-Scale Treated Palm Oil Mill Effluent
by Kah Aik Tan, Japareng Lalung, Dani Wijaya, Norli Ismail, Wan Maznah Wan Omar, Saikh Mohammad Wabaidur, Masoom Raza Siddiqui, Mahboob Alam and Mohd Rafatullah
Fermentation 2022, 8(11), 658; https://doi.org/10.3390/fermentation8110658 - 20 Nov 2022
Cited by 6 | Viewed by 2415
Abstract
The use of microalgae for the removal of contaminants such as total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD), and other pollutants from palm oil mill effluent (POME) has recently received much attention. This study aimed to investigate the impact of [...] Read more.
The use of microalgae for the removal of contaminants such as total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD), and other pollutants from palm oil mill effluent (POME) has recently received much attention. This study aimed to investigate the impact of POME as a nutrient on microalgal growth and the rate at which nutrients were removed. Three green microalgae species were isolated from Penang, Malaysia’s palm oil mill. The polyphasic approach, which combines morphological and molecular observations, was used for species identification. The three green microalgae were identified as Chlorella sorokiniana, Scenedesmus quadricauda, and Chlorococcum oleofaciens. All three green microalgae were cultivated in 25%, 50%, and 75% (v/v) of lab-scale palm oil mill effluent (LABT-POME) to investigate the growth of these three green microalgae in 100 mL of BBM. Under a light microscope and a scanning electron microscope (SEM), the morphological changes of those three green microalgae (before and after cultivation in 25%, 50%, and 75% dilution of (LABT-POME)) were observed. When cultivated in LABT-POME, C. oleofaciens showed the highest growth rate compared to the other two species of green microalgae. C. oleofaciens was able to remove more than 90% of total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen from LABT-POME, as well as minimise soluble chemical oxygen demand (SCOD) by about 65%. The growth of C. oleofaciens was well fitted to the Verhulst growth kinetic model with an R2 value of 0.99 and a growth rate of 0.3195 day−1 (d−1). The results of this study show the ability of newly isolated green microalgae to remove nutrients (TP, TN, NH3–N, and SCOD) from POME, which could be used as an effective and environmentally friendly method to remove pollutants. Full article
(This article belongs to the Special Issue Research Progress of Microorganisms in Wastewater Treatment)
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11 pages, 1633 KiB  
Article
Potential Prebiotic Effect of Cava Lees: Changes in Gut Microbiota
by Alba Martín-Garcia, Javier Gonzalez-Linares, Montserrat Riu-Aumatell and Elvira López-Tamames
Fermentation 2022, 8(11), 657; https://doi.org/10.3390/fermentation8110657 - 20 Nov 2022
Cited by 1 | Viewed by 1681
Abstract
Lees are a winery by-product with a fiber-rich composition that could have a potential prebiotic effect on gut microbiota. Prebiotics cannot be digested by humans but can be used by bacteria found in the large intestine. To evaluate the potential prebiotic effect of [...] Read more.
Lees are a winery by-product with a fiber-rich composition that could have a potential prebiotic effect on gut microbiota. Prebiotics cannot be digested by humans but can be used by bacteria found in the large intestine. To evaluate the potential prebiotic effect of lees, they were administered to Wistar rats for 14 days. Feces were collected daily, and DNA was extracted and analyzed by shot gun sequencing. The supplementation with lees did not affect weight, food intake, or water consumption of the studied rats. It was found that lees promoted the increase of relative abundance of probiotic bacteria belonging to the Lactobacillaceae family, as well as other potentially probiotic species such as Blautia hansenii, Roseburia intestinalis, and Ruminococcus obeum. Moreover, lees supplementation also reduced the abundance of certain pathogenic bacteria. In conclusion, lees can improve the presence of beneficial bacteria in the gastrointestinal tract and can be re-valorized as a new ingredient in food formulation. Full article
(This article belongs to the Special Issue Nutrition and Health of Fermented Foods)
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13 pages, 2050 KiB  
Article
Changes of Physicochemical Properties in Black Garlic during Fermentation
by Xinyu Yuan, Zhuochen Wang, Lanhua Liu, Dongdong Mu, Junfeng Wu, Xingjiang Li and Xuefeng Wu
Fermentation 2022, 8(11), 653; https://doi.org/10.3390/fermentation8110653 - 20 Nov 2022
Cited by 2 | Viewed by 2760
Abstract
To investigate the changes of the main ingredients in black garlic (BG) during fermentation, the contents of moisture, total acids and reducing sugars were determined. Allicin, 5-Hydroxymethylfurfural (5-HMF), and total phenols were also determined as bioactive substances. DPPH scavenging capacity was determined to [...] Read more.
To investigate the changes of the main ingredients in black garlic (BG) during fermentation, the contents of moisture, total acids and reducing sugars were determined. Allicin, 5-Hydroxymethylfurfural (5-HMF), and total phenols were also determined as bioactive substances. DPPH scavenging capacity was determined to indicate the antioxidant activity of BG. The changes in hardness and color were detected as well. The results showed that the moisture content decreased from 66.13% to 25.8% during the fermentation. The content of total acids, total phenols, and reducing sugars increased from 0.03 g/g to 0.29 g/g, from 0.045 μg/g to 0.117 μg/g, and from 0.016 g/g to 0.406 g/g, respectively. The content of 5-HMF increased from 0 to 4.12 μg/mL continuously, while the content of allicin increased from 0.09 mmol/100 g to 0.30 mmol/100 g and then decayed to 0.00 mmol/100 g. The L*, a*, and b* values of BG were 23.65 ± 0.44, 0.64 ± 0.06, and 0.85 ± 0.05, respectively. There was a higher intensity of dark color in BG than that in fresh garlic. The hardness values decreased first and then increased in later fermentation from 465.47 g to 27,292.38 g. Principal component analysis (PCA) showed that the samples were divided into three clusters, including cluster1 (fresh garlic, S0), cluster2 (S1), and cluster3 (S3−S9). This research effectively clarified the various stage of the BG fermentation process, and it is expected to supply references for reducing production time in industrial BG fermentation. Full article
(This article belongs to the Special Issue Applied Microorganisms and Industrial/Food Enzymes)
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16 pages, 1684 KiB  
Review
Nonconventional Yeasts Engineered Using the CRISPR-Cas System as Emerging Microbial Cell Factories
by Jongbeom Park, In Jung Kim and Soo Rin Kim
Fermentation 2022, 8(11), 656; https://doi.org/10.3390/fermentation8110656 - 19 Nov 2022
Cited by 5 | Viewed by 2974
Abstract
Because the petroleum-based chemical synthesis of industrial products causes serious environmental and societal issues, biotechnological production using microorganisms is an alternative approach to achieve a more sustainable economy. In particular, the yeast Saccharomyces cerevisiae is widely used as a microbial cell factory to [...] Read more.
Because the petroleum-based chemical synthesis of industrial products causes serious environmental and societal issues, biotechnological production using microorganisms is an alternative approach to achieve a more sustainable economy. In particular, the yeast Saccharomyces cerevisiae is widely used as a microbial cell factory to produce biofuels and valuable biomaterials. However, product profiles are often restricted due to the Crabtree-positive nature of S. cerevisiae, and ethanol production from lignocellulose is possibly enhanced by developing alternative stress-resistant microbial platforms. With desirable metabolic pathways and regulation in addition to strong resistance to diverse stress factors, nonconventional yeasts (NCY) may be considered an alternative microbial platform for industrial uses. Irrespective of their high industrial value, the lack of genetic information and useful gene editing tools makes it challenging to develop metabolic engineering-guided scaled-up applications using yeasts. The recently developed clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) system is a powerful gene editing tool for NCYs. This review describes the current status of and recent advances in promising NCYs in terms of industrial and biotechnological applications, highlighting CRISPR-Cas9 system-based metabolic engineering strategies. This will serve as a basis for the development of novel yeast applications. Full article
(This article belongs to the Special Issue Yeast Biotechnology 6.0)
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15 pages, 2266 KiB  
Article
Efficient Purification of 2′-Fucosyllactose by Membrane Filtration and Activated Carbon Adsorption
by Yuanyifei Wang, Jiaqiang Hu, Mengyu Sun, Bo Peng and Shuo Wang
Fermentation 2022, 8(11), 655; https://doi.org/10.3390/fermentation8110655 - 19 Nov 2022
Cited by 2 | Viewed by 2150
Abstract
With the rapid development of synthetic biology, the production of 2′-fucosyllactose by biological fermentation gradually has the basis for industrialization. However, the lack of efficient downstream technology of biological fermentation, especially purification technology, has become the main factor limiting its commercialization. In this [...] Read more.
With the rapid development of synthetic biology, the production of 2′-fucosyllactose by biological fermentation gradually has the basis for industrialization. However, the lack of efficient downstream technology of biological fermentation, especially purification technology, has become the main factor limiting its commercialization. In this study, based on the general E. coli biosynthesis of 2′-fucosyllactose fermentation broth, most of the impurities were removed and concentrated using membrane filtration technology after simple flocculation. The target 2′-fucosyllactose was eluted in a targeted manner using activated carbon adsorption and ethanol gradient elution technology. The 2′-fucosyllactose product with 90% or even higher purity could be prepared efficiently. This study explored a new direction for the industrial production of 2′-fucosyllactose. Full article
(This article belongs to the Special Issue Separation and Purification of Biosynthetic Products)
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16 pages, 2201 KiB  
Article
Improving Aroma Complexity with Hanseniaspora spp.: Terpenes, Acetate Esters, and Safranal
by Juan Manuel del Fresno, Carlos Escott, Francisco Carrau, José Enrique Herbert-Pucheta, Cristian Vaquero, Carmen González and Antonio Morata
Fermentation 2022, 8(11), 654; https://doi.org/10.3390/fermentation8110654 - 19 Nov 2022
Cited by 8 | Viewed by 2775
Abstract
Hanseniaspora vineae and Hanseniaspora opuntiae are apiculate yeasts normally found on the skins of ripe grapes and at the beginning of alcoholic fermentation. Several studies have reported that these species can provide interesting sensory characteristics to wine by contributing high levels of acetate [...] Read more.
Hanseniaspora vineae and Hanseniaspora opuntiae are apiculate yeasts normally found on the skins of ripe grapes and at the beginning of alcoholic fermentation. Several studies have reported that these species can provide interesting sensory characteristics to wine by contributing high levels of acetate esters and can increase the mouthfeel and body of wines. The present work aims to evaluate the use of these two species sequentially with Saccharomyces cerevisiae to improve the sensory profile of Albillo Mayor white wines. The fermentations were carried out in triplicate in 150 L stainless steel barrels. At the end of the alcoholic fermentation polysaccharides, colour, and an extensive study of the aromatic profiles were measured. Results showed up to 1.55 times higher content of 2-phenylethanol in H. opuntiae wines and up to three times higher concentration of fermentative esters in H. vineae wines than in the controls. Interestingly, it should be noted that the compound safranal was identified only in the H. vineae wines. These results indicated that the species studied are an interesting bio-tool to improve the aromatic profile of Albillo Mayor white wines. A novel non-targeted NMR-based metabolomics approach is proposed as a tool for optimising wine productions with standard and sequential fermentation schemes using apiculate yeast strains due to its discriminant capacity to differentiate fine features between wine samples from the identical geographical origin and grape variety but diverse fermentations or vintages. Full article
(This article belongs to the Special Issue Enological Repercussions of Non-saccharomyces Species 4.0)
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14 pages, 2537 KiB  
Article
Overexpression of LAS21 in Cellulase-Displaying Saccharomyces cerevisiae for High-Yield Ethanol Production from Pretreated Sugarcane Bagasse
by Jantima Arnthong, Piyada Bussadee, Apisan Phienluphon, Pacharawan Deenarn, Kan Tulsook, Sa-ngapong Plupjeen, Chatuphon Siamphan, Chakrit Tachaapaikoon, Verawat Champreda and Surisa Suwannarangsee
Fermentation 2022, 8(11), 652; https://doi.org/10.3390/fermentation8110652 - 18 Nov 2022
Cited by 5 | Viewed by 1959
Abstract
The valorization of lignocellulosic feedstocks into biofuels and biochemicals has received much attention due to its environmental friendliness and sustainability. However, engineering an ideal microorganism that can both produce sufficient cellulases and ferment ethanol is highly challenging. In this study, we have tested [...] Read more.
The valorization of lignocellulosic feedstocks into biofuels and biochemicals has received much attention due to its environmental friendliness and sustainability. However, engineering an ideal microorganism that can both produce sufficient cellulases and ferment ethanol is highly challenging. In this study, we have tested seven different genes that are involved in glycosylphosphatidylinositol (GPI) biosynthesis and remodeling for the improvement of cellulase activity tethered on the S. cerevisiae cell surface. It was found that the overexpression of LAS21 can improve β-glucosidase activity by 48.8% compared to the original strain. Then, the three cellulase genes (cellobiohydrolase, endoglucanase, and β-glucosidase) and the LAS21 gene were co-introduced into a diploid thermotolerant S. cerevisiae strain by a multiple-round transformation approach, resulting in the cellulolytic ECBLCCE5 strain. Further optimization of the bioprocess parameters was found to enhance the ethanol yield of the ECBLCCE5 strain. Scaling up the valorization of pretreated sugarcane bagasses in a 1 L bioreactor resulted in a maximum ethanol concentration of 28.0 g/L (86.5% of theoretical yield). Our study provides a promising way to improve the economic viability of second-generation ethanol production. Moreover, the engineering of genes involved in GPI biosynthesis and remodeling can be applied to other yeast cell surface display applications. Full article
(This article belongs to the Special Issue Biodegradation and Fermentation in Biorefinery)
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13 pages, 1991 KiB  
Article
Simultaneous Production and Immobilization of Lipase Using Pomegranate-Seed Residue: A New Biocatalyst for Hydrolysis Reactions and Structured Lipids Synthesis
by Marianne M. Diniz, Adejanildo da S. Pereira, Gabriel Albagli and Priscilla F. F. Amaral
Fermentation 2022, 8(11), 651; https://doi.org/10.3390/fermentation8110651 - 18 Nov 2022
Cited by 1 | Viewed by 1608
Abstract
Pomegranate-seed residue (PSR) was used in a new strategy for the simultaneous production of Yarrowia lipolytica lipase by submerged fermentation and its immobilization by adsorption. This biocatalyst—the fermented solid residue containing the adsorbed lipase (fermPSR)—was evaluated in hydrolysis reactions and in structured lipid [...] Read more.
Pomegranate-seed residue (PSR) was used in a new strategy for the simultaneous production of Yarrowia lipolytica lipase by submerged fermentation and its immobilization by adsorption. This biocatalyst—the fermented solid residue containing the adsorbed lipase (fermPSR)—was evaluated in hydrolysis reactions and in structured lipid synthesis. In shake flasks, yeast extract and urea were the best nitrogen sources for lipase production with PSR and their simultaneous use increased the lipase production even further. This result was confirmed in a 3.5-liter bioreactor, with lipase activity in an extracellular medium of 40 U/mL. A maximum reaction rate (Vmax) of 49.5 µmol/min/g, a Michaelis–Menten constant (Km) of 207 µmol/L, and a turnover number (Kcat) of 130 s−1 were determined for the new biocatalyst, fermPSR, for the hydrolysis of p-nitrophenyl laurate (p-NPL) into p-nitrophenol. The conversion of p-NPL into p-nitrophenol in subsequent reactions confirmed fermPSR’s potential for industrial hydrolytic reactions. The production of structured lipids from vegetable oil and free fatty acids by fermPSR evidences the versatility of this new biocatalyst. Full article
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18 pages, 1521 KiB  
Article
Resource Recovery of the Wastewater-Derived Nutrients into Algal Biomass Followed by Its Cascading Processing to Multiple Products in a Circular Bioeconomy Paradigm
by Muhammad Nabeel Haider, Chen-Guang Liu, Tanveer A. Tabish, Deepanraj Balakrishnan, Pau-Loke Show, Shaza Yehya Abdulhamed Qattan, Munazza Gull and Muhammad Aamer Mehmood
Fermentation 2022, 8(11), 650; https://doi.org/10.3390/fermentation8110650 - 17 Nov 2022
Cited by 7 | Viewed by 1952
Abstract
The cultivation of Plectonema terebrans BERC10 in wastewater and integrating the wastewater-derived biomass followed by its processing for multiple products in a biorefinery could help in achieving environmental sustainability and cost effectiveness. This study evaluated the resource recovery potential of the cyanobacterium Plectonema [...] Read more.
The cultivation of Plectonema terebrans BERC10 in wastewater and integrating the wastewater-derived biomass followed by its processing for multiple products in a biorefinery could help in achieving environmental sustainability and cost effectiveness. This study evaluated the resource recovery potential of the cyanobacterium Plectonema terebrans BERC10 from urban wastewater followed by the cascading processing of the biomass into multiple bioproducts. The annual biomass productivity ranged from 0.035–0.064 gL−1d−1 and contained 40–46% lipids and 20–38% protein. The cascading processing of the biomass resulted in multiple products, including 53 mgg−1 of high-value pigments and high-quality biodiesel in accordance with American and European standards. The pigment-free and de-fatted residual biomass was used as a sole feedstock (30–70 gL−1) to produce enzymes and mycoproteins via fungal fermentation employing Aspergillus niger and Aspergillus oryzae. Interestingly, A. oryzae produced 28 UmL−1 of α-amylase and the final residues were mycoproteins after 96 h. Furthermore, the strain removed 80–90% of total phosphorous, 90–99% of total nitrogen, and significantly lowered the COD, BOD, and TDS of urban wastewater. The data demonstrated that P. terebrans has substantial potential for resource recovery and could become a candidate for a wastewater-derived algal biorefinery. Full article
(This article belongs to the Special Issue Algae—the Medium of Bioenergy Conversion)
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21 pages, 3299 KiB  
Review
Emerging Technologies for Enhancing Microalgae Biofuel Production: Recent Progress, Barriers, and Limitations
by A. G. Olabi, Abdul Hai Alami, Shamma Alasad, Haya Aljaghoub, Enas Taha Sayed, Nabila Shehata, Hegazy Rezk and Mohammad Ali Abdelkareem
Fermentation 2022, 8(11), 649; https://doi.org/10.3390/fermentation8110649 - 17 Nov 2022
Cited by 7 | Viewed by 5103
Abstract
The world has heavily relied on fossil fuels for decades to supply energy demands. However, the usage of fossil fuels has been strongly correlated with impactful problems, which lead to global warming. Moreover, the excessive use of fossil fuels has led to their [...] Read more.
The world has heavily relied on fossil fuels for decades to supply energy demands. However, the usage of fossil fuels has been strongly correlated with impactful problems, which lead to global warming. Moreover, the excessive use of fossil fuels has led to their rapid depletion. Hence, exploring other renewable and sustainable alternatives to fossil fuels is imperative. One of the most sustainable fossil fuel alternatives is biofuel. Microalgae-based biofuels are receiving the attention of researchers due to their numerous advantages compared with those obtained from other types of feedstocks. Hence, it is essential to explore the recent technologies for biofuel produced from microalgae species and define the possible challenges that might be faced during this process. Therefore, this work presents the recent advancements in biofuel production from microalgae, focusing on emerging technologies such as those using nanomaterials and genetic engineering. This review focuses on the impact of nanoparticles on the harvesting efficiency of various microalgae species and the influence of nanoparticles on biofuel production. The genetic screening performed by genome-scale mutant libraries and their high-throughput screening may assist in developing effective strategies for enhancing microalgal strains and oil production through the modification of enzymes. Furthermore, the barriers that limit the production of biofuels from microalgae are introduced. Even though microalgae-based biofuels are perceived to engage with low negative impacts on the environment, this review paper touches on several environmental issues associated with the cultivation and harvesting of microalgae species. Moreover, the economic and technical feasibility limits the production of microalgae-based biofuels. Full article
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13 pages, 1585 KiB  
Article
Ethanol Production through Optimized Alkaline Pretreated Elaeis guineensis Frond Waste from Krabi Province, Thailand
by Poomhatai Kooprasertying, Wirat Vanichsriratana, Sarote Sirisansaneeyakul, Nicom Laemsak, Afrasiab Khan Tareen, Zahoor Ullah, Pramuk Parakulsuksatid and Imrana Niaz Sultan
Fermentation 2022, 8(11), 648; https://doi.org/10.3390/fermentation8110648 - 17 Nov 2022
Cited by 3 | Viewed by 2299
Abstract
Oil palm frond as an abundant and inexpensive lignocellulosic waste was used to optimize alkaline pretreatment for ethanol production. The studied lignocellulosic waste is one of the largest biomasses (47%) in oil palm waste. Oil palm frond fibers were processed by steam explosion, [...] Read more.
Oil palm frond as an abundant and inexpensive lignocellulosic waste was used to optimize alkaline pretreatment for ethanol production. The studied lignocellulosic waste is one of the largest biomasses (47%) in oil palm waste. Oil palm frond fibers were processed by steam explosion, hot water extraction, and alkaline extraction pretreatment, followed by simultaneous saccharification and fermentation (SSF), for ethanol production as an alternative energy resource. To optimize alkaline extraction for oil palm frond, a Taguchi method with a three-factor design constituted a concentration of NaOH (15%, 20%, and 25%), time (30, 60, and 90 min), and temperature (70, 80, and 90 °C). An optimum alkaline extraction condition of 15% NaOH at 90 °C for 60 min gave the highest percentage of α-cellulose (80.74%) and the lowest percentages of lignin (15.99%), ash (1.05%), and pentosan (2.09%). In addition, the optimized pretreatment condition significantly improved α-cellulose to 52.65% and removed lignin up to 51.78%. Simultaneous saccharification and fermentation (SSF) was carried out with 10% (dry weight) alkaline pretreated OPF fibers, Celluclast 1.5 L (15 FU/gram substrate), Novozyme 188 (15 IU/gram substrate), and Saccharomyces cerevisiae SC90 at 40 and 45 °C. The highest ethanol concentration, theoretical ethanol yield, and ethanol productivity observed at 40 °C were 33.15 g/L, 72.54%, and 0.55 g/L/h, respectively. The results suggest that an optimized alkaline pretreatment process using palm frond as a lignocellulosic waste is a sustainable approach to produce efficient ethanol production. Full article
(This article belongs to the Special Issue Lignocellulosic Biorefineries and Downstream Processing)
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11 pages, 1297 KiB  
Article
Effects of Lactic Acid Bacteria Fermentation on Physicochemical Properties, Functional Compounds and Antioxidant Activity of Edible Grass
by Xianxiu Li, Tao He, Jianwei Mao and Ruyi Sha
Fermentation 2022, 8(11), 647; https://doi.org/10.3390/fermentation8110647 - 16 Nov 2022
Cited by 8 | Viewed by 2424
Abstract
Fermented foods are known worldwide for their functional health properties. In order to promote the relative product development of edible grass, Lactobacillus plantarum (Lp) and Lactobacillus rhamnosus (Lr) were used to ferment edible grass in this study. Effects of fermentation using Lp and [...] Read more.
Fermented foods are known worldwide for their functional health properties. In order to promote the relative product development of edible grass, Lactobacillus plantarum (Lp) and Lactobacillus rhamnosus (Lr) were used to ferment edible grass in this study. Effects of fermentation using Lp and Lr in monoculture and binary mixture on physicochemical properties, the contents of functional compounds and the antioxidant activity of edible grass at different fermentation times were investigated by colorimetric method and high-performance liquid chromatography (HPLC). Results show that the pH value and total sugar content of the three fermented edible grasses at the 4th day were lower than those of unfermented water extract (defined as the control sample) and kept almost unchanged at the 7th day. The total polyphenol content and total flavonoid content of the three fermented edible grasses were lower than those of the control sample by the oxidation of phenolic compounds caused by polyphenol oxidases. The highest soluble protein content and superoxide dismutase (SOD) activity were found in the binary mixture of Lp and Lr fermentation at the 7th day, which were respectively 11 and 1.78 times higher than those of control sample. The oxalic acid content of all fermented edible grasses shows a significant decrease with increasing fermentation time, especially for the binary mixture at the 7th day, reaching only 24% of the control sample. However, the contents of lactic acid and succinic acid of the three fermented edible grasses were higher than those of the control sample because of the metabolism of the microorganism. Functional compounds including soluble protein, SOD, lactic acid and succinic acid played the main positive roles in antioxidation, while oxalic acid had a negative correlation with antioxidation. Therefore, the antioxidant activity of edible grass was dramatically enhanced by Lactobacillus strain fermentation. Full article
(This article belongs to the Special Issue Nutrition and Health of Fermented Foods)
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9 pages, 247 KiB  
Review
Comparison Review of the Production, Microbiology, and Sensory Profile of Lambic and American Coolship Ales
by John Carriglio, Drew Budner and Katherine A. Thompson-Witrick
Fermentation 2022, 8(11), 646; https://doi.org/10.3390/fermentation8110646 - 16 Nov 2022
Cited by 2 | Viewed by 2240
Abstract
Sour beers have been traditionally brewed with spontaneous fermentation. This has been occurring in Belgium for hundreds of years, and more recently in the United States as the American craft beer industry has boomed. Belgian sour styles include lambics, which are mirrored in [...] Read more.
Sour beers have been traditionally brewed with spontaneous fermentation. This has been occurring in Belgium for hundreds of years, and more recently in the United States as the American craft beer industry has boomed. Belgian sour styles include lambics, which are mirrored in a burgeoning style called the American coolship ale (ACA). American beers have much more creative leeway than their Belgian counterparts, as American craft brewing tends to incorporate more contemporary techniques and ingredients than their traditional European forebears. This review paper will summarize the history, production methods, fermentation, microbiological profiles, and sensory profiles of Belgian lambics and American coolship ales. Full article
(This article belongs to the Special Issue Brewing & Distilling 3.0)
38 pages, 4985 KiB  
Review
Fermented Foods of Korea and Their Functionalities
by Su-Jin Jung, Soo-Wan Chae and Dong-Hwa Shin
Fermentation 2022, 8(11), 645; https://doi.org/10.3390/fermentation8110645 - 15 Nov 2022
Cited by 16 | Viewed by 13288
Abstract
Fermented foods are loved and enjoyed worldwide and are part of a tradition in several regions of the world. Koreans have traditionally had a healthy diet since people in this region have followed a fermented-foods diet for at least 5000 years. Fermented-product footprints [...] Read more.
Fermented foods are loved and enjoyed worldwide and are part of a tradition in several regions of the world. Koreans have traditionally had a healthy diet since people in this region have followed a fermented-foods diet for at least 5000 years. Fermented-product footprints are evolving beyond boundaries and taking the lead in the world of food. Fermented foods, such as jang (fermented soybean products), kimchi (fermented vegetables), jeotgal (fermented fish), and vinegar (liquor with grain and fruit fermentation), are prominent fermented foods in the Korean culture. These four major fermented foods have been passed down through the generations and define Korean cuisine. However, scientific advancements in the fermentation process have increased productivity rates and facilitated global exports. Recently, Korean kimchi and jang have garnered significant attention due to their nutritional and health-beneficial properties. The health benefits of various Korean fermented foods have been consistently supported by both preclinical and clinical research. Korean fermented foods effectively reduce the risk of cardiovascular and chronic metabolic diseases, such as immune regulation, memory improvement, obesity, diabetes, and high blood pressure. Additionally, kimchi is known to prevent and improve multiple metabolic diseases, including irritable bowel syndrome (IBS), and improve beneficial intestinal bacteria. These functional health benefits may reflect the synergistic effect between raw materials and various physiologically active substances produced during fermentation. Thus, fermented foods all over the world not only enrich our dining table with taste, aroma, and nutrition, but also the microorganisms involved in fermentation and metabolites of various fermentations have a profound effect on human health. This article describes the production and physiological functions of Korean fermented foods, which are anticipated to play a significant role in the wellness of the world’s population in the coming decades. Full article
(This article belongs to the Special Issue Food Fermentation for Better Nutrition, Health and Sustainability)
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17 pages, 2810 KiB  
Article
Simultaneous Production of Biohydrogen (bioH2) and Poly-Hydroxy-Alkanoates (PHAs) by a Photoheterotrophic Consortium Bioaugmented with Syntrophomonas wolfei
by Axayacatl González, Edgar Salgado, Zaira Vanegas, Cristina Niño-Navarro, Omar Cortés, Isaac Chairez and Elvia I. García-Peña
Fermentation 2022, 8(11), 644; https://doi.org/10.3390/fermentation8110644 - 15 Nov 2022
Cited by 7 | Viewed by 2380
Abstract
Mixed cultures represent better alternatives to ferment organic waste and dark fermentation products in anerobic conditions because the microbial associations contribute to electron transfer mechanisms and combine metabolic possibilities. The understanding of the microbial interactions in natural and synthetic consortia and the strategies [...] Read more.
Mixed cultures represent better alternatives to ferment organic waste and dark fermentation products in anerobic conditions because the microbial associations contribute to electron transfer mechanisms and combine metabolic possibilities. The understanding of the microbial interactions in natural and synthetic consortia and the strategies to improve the performance of the processes by bioaugmentation provide insight into the physiology and ecology of the mixed cultures used for biotechnological purposes. Here, synthetic microbial communities were built from three hydrogen (bioH2) and poly-hydroxy-alkanoates (PHA) producers, Clostridium pasteurianum, Rhodopseudomonas palustris and Syntrophomonas wolfei, and a photoheterotrophic mixed consortium C4, and their performance was evaluated during photofermentation. Higher hydrogen volumetric production rates (H2VPR) were determined with the consortia (28–40 mL/Lh) as compared with individual strains (20–27 mL/Lh). The designed consortia reached the highest bioH2 and PHA productions of 44.3 mmol and 50.46% and produced both metabolites simultaneously using dark fermentation effluents composed of a mixture of lactic, butyric, acetic, and propionic acids. When the mixed culture C4 was bioaugmented with S. wolfei, the bioH2 and PHA production reached 32 mmol and 50%, respectively. Overall, the consumption of organic acids was above 50%, which accounted up to 55% of total chemical oxygen demand (COD) removed. Increased bioH2 was observed in the condition when S. wolfei was added as the bioaugmentation agent, reaching up to 562 mL of H2 produced per gram of COD. The enhanced production of bioH2 and PHA can be explained by the metabolic interaction between the three selected strains, which likely include thermodynamic equilibrium, the assimilation of organic acids via beta-oxidation, and the production of bioH2 using a proton driving force derived from reduced menaquinone or via electron bifurcation. Full article
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11 pages, 954 KiB  
Article
Schizosaccharomyces pombe in the Brewing Process: Mixed-Culture Fermentation for More Complete Attenuation of High-Gravity Wort
by Barnaby Pownall, Struan J. Reid, Annie E. Hill and David Jenkins
Fermentation 2022, 8(11), 643; https://doi.org/10.3390/fermentation8110643 - 15 Nov 2022
Cited by 3 | Viewed by 2685
Abstract
High-gravity brewing is a method that maximises brewhouse capacity and reduces energy consumption per unit of beer produced. The fermentation of wort with high sugar content is known to impact the fermentation characteristics and production of aroma-active volatiles, and as such, cultures that [...] Read more.
High-gravity brewing is a method that maximises brewhouse capacity and reduces energy consumption per unit of beer produced. The fermentation of wort with high sugar content is known to impact the fermentation characteristics and production of aroma-active volatiles, and as such, cultures that are adapted to this method are industrially valuable. Mixed-culture fermentation offers brewers the opportunity to combine desirable features from multiple strains of yeast and to take advantage of the interactions between those strains. In this study, a highly attenuative strain of Schizosaccharomyces pombe is paired with a fast-fermenting brewing strain of Saccharomyces cerevisiae in the fermentation of wort at both standard and high gravity at centilitre scale. Mixed cultures were found to produce several esters and higher alcohols in higher concentration than in either of the parent monocultures at both standard and high gravity. The mixed culture also represented a compromise between fermentation length (modelled by the logistic equation), which was extended by the inclusion of S. pombe, and ethanol yield, which was increased. The application of mixed-culture strategies to high-gravity brewing practices may allow brewers greater flexibility in achieving desired flavour profiles whilst increasing brewhouse efficiency. Full article
(This article belongs to the Special Issue Brewing & Distilling 3.0)
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16 pages, 2011 KiB  
Article
Fermentation of Clementine Juice with Lactobacillus salivarius spp. salivarius CECT 4063: Effect of Trehalose Addition and High-Pressure Homogenization on Antioxidant Properties, Mucin Adhesion, and Shelf Life
by Cristina Gabriela Burca-Busaga, Noelia Betoret, Lucía Seguí and Cristina Barrera
Fermentation 2022, 8(11), 642; https://doi.org/10.3390/fermentation8110642 - 15 Nov 2022
Cited by 2 | Viewed by 1989
Abstract
Fermentation of fruit juices with lactic acid bacteria enhances their antioxidant properties to a different extent depending on the microbial strain and the growing media composition, which can be modified by adding certain ingredients or applying a homogenization step. This study analyzed the [...] Read more.
Fermentation of fruit juices with lactic acid bacteria enhances their antioxidant properties to a different extent depending on the microbial strain and the growing media composition, which can be modified by adding certain ingredients or applying a homogenization step. This study analyzed the effect of trehalose addition (10%, w/w) and homogenization at 100 MPa before or after Lactobacillus salivarius spp. salivarius CECT 4063 inoculation on the antioxidant profile and the microbiological properties of commercial clementine juice during 96 h fermentation. Antioxidant properties and viable cell count of 24 h-fermented juices during refrigerated storage (30 days at 4 °C) were also evaluated. Fermentation over 24 h reduced the microbial population and antioxidant content of clementine juice. Homogenizing the juice before inoculation enhanced the microbial growth but favored antioxidant degradation. Adding trehalose (10%, w/w) to the juice formulation and/or homogenizing at the fermented juice at 100 MPa for 24 h had a negative impact on viable counts and did not improve the microbial adhesion to intestinal mucosa. However, both techniques prevented antioxidant oxidation and cell decay during the storage of fermented juice under refrigeration, which should not last more than 15 days. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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11 pages, 2126 KiB  
Article
Anaerobic Digestion of Chicken Manure Assisted by Carbon Nanotubes: Promotion of Volatile Fatty Acids Consumption and Methane Production
by Elvira E. Ziganshina, Svetlana S. Bulynina and Ayrat M. Ziganshin
Fermentation 2022, 8(11), 641; https://doi.org/10.3390/fermentation8110641 - 14 Nov 2022
Cited by 9 | Viewed by 1790
Abstract
In this study, the effect of different concentrations of carbon nanotubes (Taunit-M; 0.5–6.5 g L−1) on the efficiency of anaerobic digestion of chicken manure is investigated. The highest positive effect on the specific production of methane is obtained when 5.0 g [...] Read more.
In this study, the effect of different concentrations of carbon nanotubes (Taunit-M; 0.5–6.5 g L−1) on the efficiency of anaerobic digestion of chicken manure is investigated. The highest positive effect on the specific production of methane is obtained when 5.0 g L−1 of carbon nanotubes are added to the anaerobic reactors. In addition, carbon nanotubes at these concentrations stimulate the biodegradation of volatile fatty acids, mainly acetate, butyrate, and finally propionate. The maximum production rate of methane increases by 15–16% in the presence of carbon nanotubes (5.0–6.5 g L−1). Also, addition of carbon nanotubes at certain concentrations increases total methane production. Finally, the addition of carbon nanotubes to the anaerobic reactors is found to the favor consumption of volatile fatty acids and improve the methane production kinetics and productivity during the anaerobic digestion of chicken manure. Full article
(This article belongs to the Special Issue Anaerobic Fermentation and High-Value Bioproducts)
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13 pages, 1708 KiB  
Article
Improved Sugar Recovery of Alkaline Pre-Treated Pineapple Leaf Fibres via Enzymatic Hydrolysis and Its Enzymatic Kinetics
by Noor Idayu Nashiruddin, Noor Hidayah Abd Rahman, Roshanida A. Rahman, Rosli Md. Illias, Nazlee Faisal Ghazali, Bassam Abomoelak and Hesham Ali El Enshasy
Fermentation 2022, 8(11), 640; https://doi.org/10.3390/fermentation8110640 - 14 Nov 2022
Cited by 1 | Viewed by 1896
Abstract
The biofibre complex structure in pineapple leaf fibres (PALFs) can be disrupted using the alkaline pre-treatment method with sodium hydroxide (NaOH). Nonetheless, the pre-treated structures have an impact on the bioconversion of PALFs into sugar. Thus, the impact necessitates precise reaction conditions, which [...] Read more.
The biofibre complex structure in pineapple leaf fibres (PALFs) can be disrupted using the alkaline pre-treatment method with sodium hydroxide (NaOH). Nonetheless, the pre-treated structures have an impact on the bioconversion of PALFs into sugar. Thus, the impact necessitates precise reaction conditions, which are required for the enzymatic hydrolysis of PALFs. In this study, the Box–Behnken design (BBD) was utilised to achieve maximum sugar yield from PALFs. The optimised enzymatic hydrolysis conditions were 229 µg/mL of cellulase, a reaction temperature of 45 °C, and a hydrolysis time of 69 h. Resultantly, an 84% increase in sugar yield was observed, from 17.26 mg/mL to 108.74 mg/mL after the optimisation process. Moreover, a significant influence (p = 0.0009) of the enzymatic hydrolysis on hydrolysis time and temperature was observed. Additionally, the kinetic study analysis of NaOH pre-treatment and the enzymatic hydrolysis process were investigated. The kinetics of enzyme concentrations on total reducing sugar (TRS) production using an insoluble substrate were investigated based on modified Michaelis–Menten and Chrastil models. The result of the models is in good agreement with the experimental data, as the PALF hydrolysis process was reasonably well predicted. This study provides valuable information for predicting the sugar yield of the PALF bioconversion. Full article
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9 pages, 368 KiB  
Article
Effect of Pre-Fermentative Bentonite Addition on Pinot Noir Wine Colour, Tannin, and Aroma Profile
by Pradeep M. Wimalasiri, Tanya Rutan and Bin Tian
Fermentation 2022, 8(11), 639; https://doi.org/10.3390/fermentation8110639 - 14 Nov 2022
Cited by 2 | Viewed by 1648
Abstract
Pinot noir is a grape variety with thin grape skin, which means the extraction of colour and polyphenols is more challenging than other red grape varieties. The aim of this study was to investigate the impact of protein removal by adding bentonite prior [...] Read more.
Pinot noir is a grape variety with thin grape skin, which means the extraction of colour and polyphenols is more challenging than other red grape varieties. The aim of this study was to investigate the impact of protein removal by adding bentonite prior to fermentation on Pinot noir wine composition. Four treatments were conducted, including the control without bentonite addition and Pinot noir wines produced with the addition of three different types of bentonites before cold soaking. The juice and wine samples were analysed for pathogenesis-related proteins, tannin, wine colour parameters, and aroma composition. The results showed that bentonite addition at 0.5 g/L had little impact on tannin and aroma compounds but more impact on wine colour, especially significantly higher level of SO2 resistant pigments observed in Na bentonite addition treatment. This study indicates the potential use of bentonite to modulate the Pinot noir juice composition that may facilitate the extraction of colour components from grape into juice, which plays an important role in colour stabilization in finished wine. Full article
(This article belongs to the Special Issue Wine Aromas)
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11 pages, 1940 KiB  
Article
Anaerobic Co-Digestion of Bioplastics and Food Waste under Mesophilic and Thermophilic Conditions: Synergistic Effect and Biodegradation
by Jeong-Hee Kang, Sung-Won Kang, Weon-Jae Kim, Dong-Hoon Kim and Seong-Won Im
Fermentation 2022, 8(11), 638; https://doi.org/10.3390/fermentation8110638 - 14 Nov 2022
Cited by 10 | Viewed by 2935
Abstract
To mitigate the various problems caused by using conventional plastics, bioplastic (BP) has emerged as a substitute for plastics. BP wastes after use are commonly treated using composting, causing many environmental problems. Anaerobic digestion (AD) has become prominent as an alternative method of [...] Read more.
To mitigate the various problems caused by using conventional plastics, bioplastic (BP) has emerged as a substitute for plastics. BP wastes after use are commonly treated using composting, causing many environmental problems. Anaerobic digestion (AD) has become prominent as an alternative method of producing renewable energy. The aim of this study was to estimate the methane production yield (MPY) of BPs (polylactic acid (PLA) and polyhydroxyalkanoate (PHA)) with mechanical pretreatment (particle size < 0.5 cm) and investigate the effect of co-digestion of BPs and food waste (FW). Batch experiments were conducted under mesophilic and thermophilic conditions at various mixing ratios (FW/PLA or PHA = 95:5 and 90:10 on a weight basis). During 20 d of digestion at temperatures of 37 and 55 °C, MPYs of PHA were 153.8–172.0 mL CH4/g chemical oxygen demand (COD), but that of PLA was significantly low (<25.6 mL CH4/g COD). Higher MPYs were attained at 55 °C than at 37 °C. The synergistic effects of FW addition on BP AD were observed at both temperatures, especially at 55 °C. By comparing theoretical (based on mono-digestion results) and actual (based on co-digestion results) MPYs, the synergistic effect of FW addition on MPY of co-digestion reached 8.5–26.6% and 12.7–25.5% for PLA- and PHA-fed tests, respectively. The biodegradation rates (on a volatile solids (VS) basis) of PLA and PHA were 6.0–13.7% and 49.1–52.3% and increased by 1.8–4.3 and 1.2–1.5 times in the PLA- and PHA-fed co-digestion tests, respectively. Co-digestion of FW might be a feasible treatment option for BPs combined with simple mechanical pretreatment. Full article
(This article belongs to the Topic Waste-to-Energy)
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14 pages, 4851 KiB  
Article
Antibacterial and Antibiofilm Potential of Microbial Polysaccharide Overlaid Zinc Oxide Nanoparticles and Selenium Nanowire
by Muthukumar Abinaya, Periyasamy Gnanaprakasam, Marimuthu Govindarajan, Mohammad Ahmad Wadaan, Shahid Mahboob, Arwa Mohammad Wadaan, Irfan Manzoor and Baskaralingam Vaseeharan
Fermentation 2022, 8(11), 637; https://doi.org/10.3390/fermentation8110637 - 13 Nov 2022
Cited by 3 | Viewed by 1873
Abstract
Here, we report on the synthesis of zinc oxide nanoparticles (ZnO NPs) and selenium nanowires (Se NWs) using microbial exopolysaccharides (EPS) as a mediator and then examine their antibacterial and ecotoxicity effects in vitro and in vivo, respectively. At 100 µg/mL, EPS, EPS-ZnO [...] Read more.
Here, we report on the synthesis of zinc oxide nanoparticles (ZnO NPs) and selenium nanowires (Se NWs) using microbial exopolysaccharides (EPS) as a mediator and then examine their antibacterial and ecotoxicity effects in vitro and in vivo, respectively. At 100 µg/mL, EPS, EPS-ZnO NPs, and EPS-Se NWs all exhibited potent in vitro antibacterial properties, drastically inhibiting the development of aquatic Gram(-) pathogens. In addition, antibiofilm studies using a microscope revealed that EPS, EPS-ZnO NPs, and EPS-Se NWs at 75 µg/mL prevented biofilm development. Furthermore, the in vivo toxicity was carried out via Danio rerio embryos and Ceriodaphnia cornuta. Danio rerio embryos were determined at different time intervals (6 hpf, 12 hpf, 24 hpf and 48 hpf). The maximum survival rate (100%) was obtained in a control group. Correspondingly, EPS, EPS-ZnO NPs and EPS-Se NWs treated embryos showed a considerable survival rate with 93.3%, 86.7% and 77.2%, respectively, at 100 µg/mL for 48 hpf. The total mortality of C. cornuta was seen at 100 µg/mL, with 56.7% in EPS, 60.0% in EPS-ZnO NPs, and 70.0% in EPS-Se NWs. For C. cornuta, the LC50 values for EPS, EPS-ZnO NPs, and EPS-Se NWs were 90.32, 81.99, and 62.99 µg/mL, respectively. Under a microscope, morphological alterations in C. cornuta were analyzed. After 24 h, an amount of dark substance was seen in the guts of C. cornuta exposed to 100 µg/mL, but in the control group, all of the living C. cornuta were swimming as usual. Our results show that EPS and EPS-ZnO NPs were less harmful than EPS-Se NWs, and that they were successfully employed to shield freshwater crustaceans from the toxins in aquatic environments. Full article
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11 pages, 2752 KiB  
Article
Removal Ability of Bacillus licheniformis on Waxy Cuticle on Wheat Straw Surface
by Yanpeng Luo, Xingxiang Ji, Yi Liang and Zhongjian Tian
Fermentation 2022, 8(11), 636; https://doi.org/10.3390/fermentation8110636 - 12 Nov 2022
Viewed by 1632
Abstract
The outermost surface of wheat straw (WS) is covered with hydrophobic lipophilic extracts and silica, which affects follow-up processes such as impregnation pretreatment of pulping and papermaking. In this study, a strain named Bacillus licheniformis (B. licheniformis) was screened from the [...] Read more.
The outermost surface of wheat straw (WS) is covered with hydrophobic lipophilic extracts and silica, which affects follow-up processes such as impregnation pretreatment of pulping and papermaking. In this study, a strain named Bacillus licheniformis (B. licheniformis) was screened from the black liquor of papermaking, which was used to explore the effect of its treatment on the waxy cuticle of WS. Scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) showed that the B. licheniformis had a certain destructive effect on the outer surface of WS and the content of Si on the outer surface decreased by 80%. The results of FTIR and X-ray photoelectron spectroscopy (XPS) displayed that the wax composition on the outer surface of WS decreased and the fiber structure inside appeared. The mechanical properties of paper demonstrated that the treated WS is still feasible in this field and the content of Si in the black liquor is reduced by 33%. Therefore, the WS treated by B. licheniformis can destroy the waxy cuticle on its outer surface and improve the wettability of WS. It provides a new idea to alleviate the “Si interference” problem of alkali recovery in WS traditional pulping and papermaking. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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17 pages, 1341 KiB  
Review
The Role and Significance of Bacillus and Lactobacillus Species in Thai Fermented Foods
by Bhagavathi Sundaram Sivamaruthi, Karthikeyan Alagarsamy, Natarajan Suganthy, Subramanian Thangaleela, Periyanaina Kesika and Chaiyavat Chaiyasut
Fermentation 2022, 8(11), 635; https://doi.org/10.3390/fermentation8110635 - 12 Nov 2022
Cited by 6 | Viewed by 4667
Abstract
Fermented foods (FFs) are prepared through controlled or spontaneous microbial growth, promoting the conversion of complex food components by microbial enzymatic action. FFs are common in the cuisine of Southeast Asian countries. Furthermore, FFs have recently become popular worldwide, due to their proposed [...] Read more.
Fermented foods (FFs) are prepared through controlled or spontaneous microbial growth, promoting the conversion of complex food components by microbial enzymatic action. FFs are common in the cuisine of Southeast Asian countries. Furthermore, FFs have recently become popular worldwide, due to their proposed and proven beneficial health effects. The microbes present in FFs affect the quality, taste, and flavor of the food. Thailand is famous for its versatile range of foods, especially FFs. Fermented beans, fish, meat, sausages, vegetables, and fruits are commonly consumed in Thailand. Thai fermented foods (TFFs) are a key source of bioactive micro-organisms and molecules, and several studies have detailed the isolation, identification, and characterization of potent microbial strains from TFFs; however, a detailed literature review of Bacillus and Lactobacillus species in TFFs is not available. Therefore, in this review, we summarize the available information on representative TFFs, as well as Bacillus and Lactobacillus species in TFFs and their bioactive properties. Full article
(This article belongs to the Special Issue Bacillus Species and Enzymes)
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14 pages, 288 KiB  
Article
The Effects of Two-Stage Fermented Feather Meal-Soybean Meal Product on Growth Performance, Blood Biochemistry, and Immunity of Nursery Pigs
by Hsien-Juang Huang, Bor-Chun Weng, Yueh-Sheng Lee, Cheng-Yung Lin, Yan-Der Hsuuw and Kuo-Lung Chen
Fermentation 2022, 8(11), 634; https://doi.org/10.3390/fermentation8110634 - 12 Nov 2022
Cited by 3 | Viewed by 1879
Abstract
The keratinase-producing microbes can readily change the feather waste into more bioavailable peptides and amino acids. This study aimed to improve two-stage fermented feather meal-soybean meal product (TSFP) quality with five selected Bacillus strains and Saccharomyces cerevisiae Y10, as well as investigate the [...] Read more.
The keratinase-producing microbes can readily change the feather waste into more bioavailable peptides and amino acids. This study aimed to improve two-stage fermented feather meal-soybean meal product (TSFP) quality with five selected Bacillus strains and Saccharomyces cerevisiae Y10, as well as investigate the effects of TSFP on growth performance, blood biochemistry, and immunity of nursery pigs. In trial 1, 100 hybrid piglets (Duroc x KHAPS) were randomly assigned to dietary supplementation of 5% fish meal or 5% TSFP prepared with 0, 32, 40, or 48 h in the first-stage fermentation. The results showed that the body weight (BW), average daily gain (ADG), and feed conversion ratio (FCR) of fermented groups were significantly better than the unfermented group (p < 0.05) at weeks 0 to 3 and 0 to 5. The ADG of 32-hr and 48-hr TSFP groups were better than the unfermented group (p < 0.05) at weeks 3 to 5. In trial 2, 80 hybrid piglets (Duroc × KHAPS) were randomly assigned into 5% fish meal or different supplementation levels of TSFP (32-hr first-stage fermented time) at 0, 2.5, or 5%. The 5% TSFP group had better BW, ADG, FCR, and PEF than the 0% group (p < 0.05) at weeks 0 to 5. Furthermore, the ex vivo mitogen-induced lymphoblastogenesis, the interferon-γ production, the oxidative burst activity, and the IgG production of the 5% TSFP group were higher than the fish meal group (p < 0.05). In conclusion, the first-stage fermentation time can be shortened from 48 h to 32 h using selected Bacillus strains in TSFP production when supplemented at 5% of the diet for nursery pigs shows the best growth performance and immunity. Full article
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