Journal Description
Fermentation
Fermentation
is an international, scientific, peer-reviewed, open access journal on fermentation process and technology published monthly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), PubAg, FSTA, Inspec, CAPlus / SciFinder, and other databases.
- Journal Rank: JCR - Q2 (Biotechnology & Applied Microbiology) / CiteScore - Q2 (Plant Science)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 12.9 days after submission; acceptance to publication is undertaken in 2.3 days (median values for papers published in this journal in the first half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
3.7 (2022);
5-Year Impact Factor:
4.5 (2022)
Latest Articles
Current Applications and Future Trends of Dehydrated Lactic Acid Bacteria for Incorporation in Animal Feed Products
Fermentation 2023, 9(8), 742; https://doi.org/10.3390/fermentation9080742 - 08 Aug 2023
Abstract
Several lactic acid bacteria (LAB) species have been recognized as probiotics and are of considerable interest due to their potential ability to confer health benefits upon consumption. In the animal feed sector, probiotics offer an alternative to the use of antibiotic growth promoters.
[...] Read more.
Several lactic acid bacteria (LAB) species have been recognized as probiotics and are of considerable interest due to their potential ability to confer health benefits upon consumption. In the animal feed sector, probiotics offer an alternative to the use of antibiotic growth promoters. The preservation and incorporation of probiotics into dry products requires carefully meeting several criteria and overcoming technological challenges to maintain their functionality. Drying is a crucial step in the process, but the probiotic properties of the resulting powder and the final cell viability in the food product are significantly influenced by the type of protective compounds and drying techniques employed. In light of the growing demand for functional animal products, this review focuses on the damages incurred during microorganism dehydration processes for food incorporation, and explores strategies to minimize such damages. It provides an overview of the effects of probiotic products in the animal feed industry, including their incorporation in low-moisture food matrices and key considerations for success. Additionally, it highlights postbiotics as an attractive alternative for live probiotic cells with many technological advantages.
Full article
(This article belongs to the Section Fermentation for Food and Beverages)
►
Show Figures
Open AccessArticle
The Effect of Dietary Fermented Grape Pomace Supplementation on In Vitro Total Gas and Methane Production, Digestibility, and Rumen Fermentation
by
and
Fermentation 2023, 9(8), 741; https://doi.org/10.3390/fermentation9080741 - 07 Aug 2023
Abstract
The aim of this study comprises the effect of fermented grape pomace (FGP) in experimental total mixed rations (TMR) at different rates (0, 7.5%, 15%, and 22.5%) on the in vitro cumulative gas production (6th, 12th, 18th and 24th hours), methane production, ruminal
[...] Read more.
The aim of this study comprises the effect of fermented grape pomace (FGP) in experimental total mixed rations (TMR) at different rates (0, 7.5%, 15%, and 22.5%) on the in vitro cumulative gas production (6th, 12th, 18th and 24th hours), methane production, ruminal fermentation values, pH and ammonia-nitrogen and straight and branched short-chain fatty acids (SCFA and BCFA) concentration. The method of in vitro total gas production was carried out in glass syringes. Ruminal in vitro methane production linearly decreased by adding up to 22.5% FGP in experimental TMR (p < 0.05). The molarities of acetic, propionic, butyric, and valeric acids in the in vitro fermentation fluid linearly decreased with the addition of FGP to TMR (p < 0.05). FGP up to 22.5% in experimental TMRs decreased the molarity of iso-valeric acid and iso-butyric acid from BSCFAs (p < 0.05). As a result, it was concluded that the use of FGP, containing a low level of total condensed tannins (TCTs), up to 22.5% in the experimental TMR based on dry matter (DM) did not adversely affect the in vitro ruminal fermentation value and had an anti-methanogenic effect. In addition, some SCFA (acetic, propionic, butyric, and valeric acids) molarities and iso-acid BSCFA (iso-butyric and iso-valeric acid) did not change up to 15% rate of FGP in the ration. Still, these values decreased by using a 22% rate of FGP. The dose-dependent effect of FGP on ruminal iso-acids has been associated with the ability of TCTs to inhibit ruminal protein degradation partially.
Full article
(This article belongs to the Section Industrial Fermentation)
Open AccessArticle
Impact of Lactobacillus acidophilus—La5 on Composition and Metabolism of the Intestinal Microbiota of Type 2 Diabetics (T2D) and Healthy Individuals Using a Microbiome Model
by
, , , , and
Fermentation 2023, 9(8), 740; https://doi.org/10.3390/fermentation9080740 - 07 Aug 2023
Abstract
Type 2 diabetes is characterized by dysbiosis in the gut, which may lead to systemic inflammation. Therefore, the use of probiotics may help to achieve a balanced microbiota and improve glycemic control. The aim of this study was to verify the impact of
[...] Read more.
Type 2 diabetes is characterized by dysbiosis in the gut, which may lead to systemic inflammation. Therefore, the use of probiotics may help to achieve a balanced microbiota and improve glycemic control. The aim of this study was to verify the impact of Lactobacillus acidophilus—La5 on the gut microbiome of type 2 diabetes adults using the Human Gut Microbial Ecosystem Simulator (SHIME®) and compare this to the microbiome of healthy subjects. Four groups (Control Group: NormoGlycemic; Treatment Group: T2D) were evaluated in SHIME® for 6 weeks. After 7 and 14 days of colonic fermentation, the intestinal microbiota (16S rRNA gene sequencing) and metabolites (short-chain fatty acids) were analyzed. La5 altered the composition of the microbiota after 14 days of treatment for both groups, by increasing the abundance of Bacteroidetes and a decrease in Firmicutes in the NormoGlycemic. Treatment with La5 resulted in a shift in the microbial community of NormoGlycemic with increased abundance of Bacteroides and Mitsuokella and a decrease in Achromobacter and Catabacter, whereas T2D gut microbiome was enriched with Faecalibacterium and reduced in Bacteroides. Megasphaera spp. stimulated with La5 treatment in NormoGlycemic has already been reported to produce intestinal metabolites and recognized to contribute to increased anti-inflammatory and immune responses. Faecalibacterium, on the other hand, can modulate the intestinal epithelium and be a major butyrate product in the microbiota. Finally, this study showed a positive and promising result of La5 treatment in increasing intestinal homeostasis in the microbiota of T2D.
Full article
(This article belongs to the Special Issue Recent Trends in Probiotics and Gut Microbiome for Human Health)
►▼
Show Figures
Figure 1
Open AccessArticle
Effect of Condensed Tannins on Nitrogen Distribution and Metabolome after Aerobic Exposure of Sainfoin Silage
Fermentation 2023, 9(8), 739; https://doi.org/10.3390/fermentation9080739 - 07 Aug 2023
Abstract
(1) Background: Previous studies have indicated that proteolysis is inhibited by the condensed tannins (CTs) that are present during sainfoin ensiling. Whether inhibiting this effect of CTs on proteolysis is functional during aerobic exposure is still unclear. (2) Methods: the present study investigated
[...] Read more.
(1) Background: Previous studies have indicated that proteolysis is inhibited by the condensed tannins (CTs) that are present during sainfoin ensiling. Whether inhibiting this effect of CTs on proteolysis is functional during aerobic exposure is still unclear. (2) Methods: the present study investigated the effect of CTs on metabolite composition during the aerobic exposure of sainfoin silage via the use of polyethylene glycol (PEG), leading to the inactivation of CTs. (3) Results: The neutral detergent-insoluble protein (NDIP) and acid detergent-insoluble protein concentrations were both more concentrated in the control group than in the PEG-treated group. There were 587 and 651 different metabolites present in the control and PEG-treated groups after 3 and 7 days, respectively, of aerobic exposure of silage. Flavonoids (72 metabolites) were the most abundant among these different metabolites. The addition of PEG upregulated histidine, threonine, asparagine, tryptophan, and glutamine, but downregulated phenylalanine. The relative abundances of Lactococcus, Fructobacillus, Enterobacter, Cutibacterium, Citrobacter, and Rosenbergiella differed significantly between the control and PEG-treated groups (p < 0.05); all of these bacteria showed significant correlation with some of the 50 most abundant metabolites. (4) Conclusions: the results suggest that the antioxidant status of the silage increased and inhibited the activity of a variety of bacteria that coexist with CTs, and decreased the production of certain amino acids after the aerobic exposure of silage.
Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
►▼
Show Figures
Figure 1
Open AccessReview
The Human Body as an Ethanol-Producing Bioreactor—The Forensic Impacts
by
Fermentation 2023, 9(8), 738; https://doi.org/10.3390/fermentation9080738 - 07 Aug 2023
Abstract
Auto-brewery syndrome (ABS), also called gut fermentation syndrome, is an extremely infrequent but also underrecognized disorder where ethanol is produced endogenously, similar to a typical bioreactor. The reliability of forensic alcohol analysis results is frequently challenged as the ethanol concentration in the breath,
[...] Read more.
Auto-brewery syndrome (ABS), also called gut fermentation syndrome, is an extremely infrequent but also underrecognized disorder where ethanol is produced endogenously, similar to a typical bioreactor. The reliability of forensic alcohol analysis results is frequently challenged as the ethanol concentration in the breath, blood, and/or urine constitutes important evidence for prosecuting drivers under the influence of the alcohol. This further emphasizes the need to understand ABS, as in legal proceedings it is often presented as grounds for acquittal due to the concept that the findings could have corresponded to endogenously produced ethanol. However, this rare and underdiagnosed medical condition should not be considered as purely a lawyer’s favorite argument. Manifestations of ABS can have a severe impact on a patient’s life and pose social consequences as well. Unfortunately, barely anything has been unearthed, and aspects such as genetic susceptibility, gut-mucus-eating microorganisms, and fecal microbiome transplantation were reviewed for the first time in this context. The framework of this review was not limited to the gut microbiota exclusively; moreover, the overgrowth of microorganisms is linked to the use of antibiotics. Studies have indicated that carbohydrate fermentation occurs in locations other than in intra-intestinal flora. Accordingly, the literature was searched for cases of patients with ABS with yeast infections in their genitourinary or oral systems.
Full article
(This article belongs to the Section Fermentation for Food and Beverages)
►▼
Show Figures
Figure 1
Open AccessReview
Metabolic Engineering of Microorganisms to Produce L-Aspartate and Its Derivatives
Fermentation 2023, 9(8), 737; https://doi.org/10.3390/fermentation9080737 - 06 Aug 2023
Abstract
Metabolic engineering is a promising strategy to realize green synthesis of valued chemicals derived from petroleum. According to the literature, cell factories for producing L-aspartate and its derivatives (β-alanine, ectoine, 3-hydroxypropionate, D-pantothenic acid and L-homoserine) have been developed. In this review, we firstly
[...] Read more.
Metabolic engineering is a promising strategy to realize green synthesis of valued chemicals derived from petroleum. According to the literature, cell factories for producing L-aspartate and its derivatives (β-alanine, ectoine, 3-hydroxypropionate, D-pantothenic acid and L-homoserine) have been developed. In this review, we firstly introduced the functions, applications and markets of L-aspartate and its derivatives. Then, the current research progress on microbial production of them was elaborated in detail. Finally, we have discussed the limiting factors and given some suggestions for realizing applications of engineered bacteria in the industry, including metabolic engineering of the bacteria to increase the titer, yield and productivity of the target products, fermentation condition optimization and downstream purification. With the development of novel technologies and increased investments in synthetic biology, it is promising to realize sustainable production of L-aspartate and its derivatives at the industrial scale in the future.
Full article
(This article belongs to the Special Issue Microbial Fermentation of Organic Wastes for Production of Biofuels and Biochemicals 2.0)
►▼
Show Figures
Figure 1
Open AccessArticle
The Microbial Community in a Substrate of Solid-State Fermentation by Lentinula edodes: A Preliminary Study
by
, , , , , and
Fermentation 2023, 9(8), 736; https://doi.org/10.3390/fermentation9080736 - 06 Aug 2023
Abstract
Edible-fungal-based solid-state fermentation holds promise for sustainable food and biofuel production. Understanding the role of microbial communities in fungal substrates is crucial. Birch-based substrates were treated with autoclaving (121 °C, at 2 bar) or hot air pasteurization (75–100 °C), followed by incubation with
[...] Read more.
Edible-fungal-based solid-state fermentation holds promise for sustainable food and biofuel production. Understanding the role of microbial communities in fungal substrates is crucial. Birch-based substrates were treated with autoclaving (121 °C, at 2 bar) or hot air pasteurization (75–100 °C), followed by incubation with and without shiitake (Lentinula edodes) inoculum. Mycelial growth was monitored by CO2 release and microbial biomass by phosphate-lipid fatty acid (PLFA). DNA sequencing was used to analyze the microbial communities. Results showed successful colonization of shiitake on all substrates, regardless of pasteurization temperatures and coexisting microbes. Total microbial respiration (CO2) and PLFA biomass showed no significant differences between pasteurization regimes. However, significant microbial differences were found between shiitake-inoculated and non-inoculated treatments. DNA sequencing revealed the dominance of Phyllobacterium, Sphingomonas, and Pelomonas genera in all inoculated substrates, while non-inoculated substrates were abundant in Bacillus spp. and Paenibacillus spp. of the Firmicutes phylum. This study provides preliminary insights into the microbial community in birch-based shiitake substrates, facilitating further investigation of bacteria involved in shiitake mycelium growth promotion and biochemical conversion for biofuel production.
Full article
(This article belongs to the Special Issue Solid State Fermentation for Microbial Synthesis)
►▼
Show Figures
Figure 1
Open AccessArticle
Optimization of Biomass Cultivation from Tuber borchii and Effect of Additives on Triterpenoid Production
Fermentation 2023, 9(8), 735; https://doi.org/10.3390/fermentation9080735 - 06 Aug 2023
Abstract
Edible fungi are renowned for producing biologically active secondary metabolites that possess anti-tumor activity, protect the liver and have other benefits. The cultivation of truffle mycelia through submerged fermentation has gained interest in the production of metabolites for bio-medicinal purposes. In the present
[...] Read more.
Edible fungi are renowned for producing biologically active secondary metabolites that possess anti-tumor activity, protect the liver and have other benefits. The cultivation of truffle mycelia through submerged fermentation has gained interest in the production of metabolites for bio-medicinal purposes. In the present study, Tuber borchii was cultivated by submerged fermentation to produce both biomass and triterpenoids. Various additives, including palmitic acid, stearic acid, linoleic acid, chitosan, CaCl2 and limonene, were investigated to enhance triterpenoid production. It was observed that increasing the medium’s linoleic acid concentration to 1 g/L increased the production of triterpenoids to 129.29 ± 6.5 mg/L, which was 2.94 times higher than the control. A number of variables, including potassium and magnesium ion concentrations and carbon and nitrogen sources and concentrations, were considered to ascertain the ideal conditions for T. borchii growth in submerged fermentation. The best concentrations for glucose, yeast extract, peptone, malt extract, KH2PO4 and MgSO4·7H2O in submerged fermentation were 19.45, 4.58, 7.91, 5.3, 0.58 and 0.82 g/L, respectively, according to response surface methodology. Validation analysis revealed that the experimental values and the predicted values were in good agreement. Under ideal circumstances, the maximum dry cell weight (2.980.18 g/L), which was 1.39 times greater than the control, was attained. Finally, the addition of 1.5 g/L linoleic acid on day 14 to the optimal medium elevated the triterpenoid production to 212.63 ± 16.58 mg/L, which was a 4.84-fold increase compared to the control.
Full article
(This article belongs to the Special Issue Polysaccharides Fermentation)
►▼
Show Figures
Figure 1
Open AccessArticle
Solid State and Semi-Solid Fermentations of Olive and Sunflower Cakes with Yarrowia lipolytica: Impact of Biological and Physical Pretreatments
Fermentation 2023, 9(8), 734; https://doi.org/10.3390/fermentation9080734 - 06 Aug 2023
Abstract
Lignocellulosic biomass is a promising feedstock for added value compound production in biotechnological processes such as solid-state fermentation (SSF). Although these solid materials can be directly used as substrates in fermentations in a solid state, a pretreatment is often required, especially if the
[...] Read more.
Lignocellulosic biomass is a promising feedstock for added value compound production in biotechnological processes such as solid-state fermentation (SSF). Although these solid materials can be directly used as substrates in fermentations in a solid state, a pretreatment is often required, especially if the microorganism selected is unable to produce lignocellulosic enzymes. In the present work, several pretreatment strategies were applied to a 50% (w/w) mixture of olive and sunflower cakes before SSF for lipase production by the oleaginous yeast Yarrowia lipolytica W29. Co-culture strategies with Y. lipolytica and Aspergillus niger did not improve lipase production by the oleaginous yeast. Biological pretreatment with a fungal enzymatic extract led to a significant increase in sugar availability in the substrate mixture after a short incubation period, improving yeast growth. Microwave and ultrasound were the physical pretreatments selected and microwave irradiation proved to be the best method, resulting in 44% and 17% increases in yeast growth and lipase production, respectively, compared to the untreated mixture. An improvement in lipase activity was also observed after ultrasonic treatment in semi-solid fermentations, leading to a 2-fold increase in this enzyme activity compared to the control. The utilization of pretreatments before SSF with Y. lipolytica can increase sugars availability and result in structural changes in the solid substrate, which can improve the bioprocesses’ productivity.
Full article
(This article belongs to the Special Issue Yarrowia lipolytica: A Beneficial Yeast as a Biofactory for Biotechnological Applications: 2nd Edition)
►▼
Show Figures
Figure 1
Open AccessArticle
Dynamics of Physicochemical Properties, Flavor, and Microbial Communities of Salt-Free Bamboo Shoots during Natural Fermentation: Correlation between Microorganisms and Metabolites
Fermentation 2023, 9(8), 733; https://doi.org/10.3390/fermentation9080733 - 06 Aug 2023
Abstract
Sour bamboo shoot is a Chinese fermented vegetable with unique flavors and is favored by local consumers. In this study, at different fermentation times, the texture of bamboo shoots and the changing rules of pH, titratable acid (TA), reduced sugar, and nitrite in
[...] Read more.
Sour bamboo shoot is a Chinese fermented vegetable with unique flavors and is favored by local consumers. In this study, at different fermentation times, the texture of bamboo shoots and the changing rules of pH, titratable acid (TA), reduced sugar, and nitrite in bamboo shoot fermentation broth were explored. Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dominant aroma compounds. 16S rRNA high-throughput sequencing technology (HTS) was employed to investigate the core microbial communities. The results show that the chewiness, fracturability, hardness, and pH decreased, while TA increased during the 60-day fermentation. The contents of reducing sugar and nitrite peaked on the 14th day of fermentation and then decreased. A total of 80 volatile compounds were detected during sour bamboo shoot fermentation, with 2,4-Di-tert-butylphenol having the highest concentration. Among them, 12 volatile compounds (VIP ≥ 1) were identified as characteristic aroma substances of sour bamboo shoots. The dominant bacterial phyla in sour bamboo shoots were Firmicutes and Proteobacteria, while Bacillus and Acinetobacter were the dominant genus. Correlation analysis showed that Firmicutes exhibited a positive correlation with 3,6-Nonadien-1-ol, (E,Z)-, Oxalic acid, isobutyl hexyl ester, and (-)-O-Acetylmalic anhydride, whereas Bacillus exhibited a negative correlation with Silanediol, dimethyl-, and Oxime-, methoxy-phenyl-. A detailed picture of the microbial community of fermented bamboo shoots has been provided by this study, and it may provide insight into the Chinese traditional fermented vegetable microbial structure.
Full article
(This article belongs to the Topic Advances in Analysis of Flavors and Fragrances: Chemistry, Properties and Applications in Food Quality Improvement)
►▼
Show Figures
Figure 1
Open AccessArticle
Fungal Bioprocessing to Improve Quality of Pennycress Meal as a Potential Feeding Ingredient for Monogastric Animals
Fermentation 2023, 9(8), 732; https://doi.org/10.3390/fermentation9080732 - 05 Aug 2023
Abstract
Pennycress, as an annual cover crop in North America, has around 30–36% of oil and 20–25% of crude protein. Pennycress oil can be converted into biodiesel, while pennycress meal (PM) has limited use in animal nutrition, mainly due to the high content of
[...] Read more.
Pennycress, as an annual cover crop in North America, has around 30–36% of oil and 20–25% of crude protein. Pennycress oil can be converted into biodiesel, while pennycress meal (PM) has limited use in animal nutrition, mainly due to the high content of glucosinolates and indigestible fiber. The nutrition of PM can be improved by processing with edible fungi. This study used Pleurotus ostreatus (PO), Rhizopus oryzae (RO), Aspergillus oryzae (AO), and Mucor circinelloides (MC) to ferment PM (60% moisture content) at 28 °C for 6 to 12 days. Compared to non-fermented PM, essential amino acids such as threonine (Thr) in PO and AO and tryptophan (Trp) and lysine (Lys) in all fungal treatments were enriched. PM fermented by all fungi resulted in concentrated digestible fiber (cellulose) at 12–46%. RO, AO, and MC-fermented PM had degraded sinigrin by 81, 33, and 12% and phytate by 47%, 37%, and 33%, with a corresponding increase in free P by 44%, 1.17-fold, and 89%, respectively. In addition, zearalenone was reduced by 97%, 50%, 39.3%, and 32% in PO, RO, AO, and MC-fermented PM, respectively. This study demonstrated the feasibility of fungi to improve the feeding value of PM, potentially promoting the economic return of pennycress plantations.
Full article
(This article belongs to the Special Issue Bioconversion of Agricultural Wastes into High-Nutrition Animal Feed)
►▼
Show Figures
Figure 1
Open AccessArticle
Exploring the Possibility of Enriching Fermented Milks with Young Barley Leaves Powder Preparation
Fermentation 2023, 9(8), 731; https://doi.org/10.3390/fermentation9080731 - 04 Aug 2023
Abstract
Barley (Hordeum vulgare L.) is one of the first cereals that humans began to cultivate. This study aimed to investigate the possibility of enriching fermented dairy products, using fermented milk as an example, with young barley leaves powder (YBLP) preparation including different
[...] Read more.
Barley (Hordeum vulgare L.) is one of the first cereals that humans began to cultivate. This study aimed to investigate the possibility of enriching fermented dairy products, using fermented milk as an example, with young barley leaves powder (YBLP) preparation including different starter cultures of lactic acid bacteria (LAB). The addition of YBLP did not affect the maximum rate of acidification and the time at which the maximum acidification rate was achieved. However, it did impact the time required to reach the desired pH level (4.6) for specific starter cultures. Over a 28-day storage period, gradual acidification of the fermented milk was observed. The addition of YBLP has a limited effect on the pH of the fermented milk, with the pH value primarily dependent on the type of starter culture and storage time. The addition of YBLP may have a positive effect on the survival of bacterial cells during the storage of the fermented milk; however, a gradual decrease in the number of LAB cells was observed during refrigerated storage. Furthermore, the addition of YBLP had a significant effect on the hardness, adhesion, and water-holding capacity of some fermented milk immediately after fermentation, depending on the specific starter culture used.
Full article
(This article belongs to the Special Issue New Insights into the Application of Lactic Acid Bacteria Strain in the Fermentation 2.0)
►▼
Show Figures
Figure 1
Open AccessArticle
Effects of Microencapsulated Blend of Organic Acids and Pure Botanicals on the Ruminal Microbiota in an In Vitro Dual-Flow Continuous Culture System
Fermentation 2023, 9(8), 730; https://doi.org/10.3390/fermentation9080730 - 04 Aug 2023
Abstract
The objective of the study was to evaluate the effects of dietary supplementation of a microencapsulated blend of organic acids and pure botanicals (mOAPBs) on the solid- and liquid-associated microenvironment (SAM and LAM, respectively) of the ruminal microbiome using an in vitro dual-flow
[...] Read more.
The objective of the study was to evaluate the effects of dietary supplementation of a microencapsulated blend of organic acids and pure botanicals (mOAPBs) on the solid- and liquid-associated microenvironment (SAM and LAM, respectively) of the ruminal microbiome using an in vitro dual-flow continuous culture system. Ruminal content was incubated in eight fermenters and the basal diet was supplemented with increasing levels of mOAPBs (0; 0.12; 0.24; or 0.36% DM) which contained 55.6% hydrogenated and refined palm oil, 25% citric acid, 16.7% sorbic acid, 1.7% thymol, and 1% vanillin. All diets had a similar nutritional composition (16.1 CP, 30.9 NDF, and 32.0 starch, % DM basis). After 7 days of adaptation, a pooled sample across the days was collected in each period for identification of the microbiome of SAM and LAM. There was no effect of mOAPB on alpha-, beta-diversity, and microbial abundance. The SAM had a greater bacterial diversity and the principal component analysis demonstrated that it had a divergent bacterial profile from LAM. Additionally, SAM had an increased abundance of carbohydrate-degrading microorganisms. In summary, mOAPBs did not modulate the ruminal microbiome. The microenvironment microbiome of solid- and liquid-associated microenvironments were different, with SAM having a greater carbohydrate-degrading microorganism population.
Full article
(This article belongs to the Special Issue In Vitro Digestibility and Ruminal Fermentation Profile)
►▼
Show Figures
Figure 1
Open AccessReview
Advances in Synthetic Biology Techniques and Industrial Applications of Corynebacterium glutamicum
Fermentation 2023, 9(8), 729; https://doi.org/10.3390/fermentation9080729 - 04 Aug 2023
Abstract
Corynebacterium glutamicum is a Gram-positive bacterium (non-spore-forming) that has been wildly used for amino acid production. Due to its stable protein secretion, low extracellular hydrolase activity, and non-toxicity, the application field of C. glutamicum has been greatly expanded. Currently, gene editing technology based
[...] Read more.
Corynebacterium glutamicum is a Gram-positive bacterium (non-spore-forming) that has been wildly used for amino acid production. Due to its stable protein secretion, low extracellular hydrolase activity, and non-toxicity, the application field of C. glutamicum has been greatly expanded. Currently, gene editing technology based on synthetic biology has great potential for synthetic biology research and genetic modification in C. glutamicum because of its ability to efficiently regulate the physiological and metabolic networks of the strain. Therefore, we summarize the gene editing tools and strategies of C. glutamicum from the aspects of genetic modification and expression elements, and we also describe the effects of gene editing techniques on a variety of products such as amino acids and their derivatives, recombinant proteins, and functional sugars, which provide a certain theoretical basis for the research on the modification of C. glutamicum strains and industrial applications. Finally, we prospect the design and industrial application of C. glutamicum genetic modification from multiple perspectives based on gene editing techniques.
Full article
(This article belongs to the Special Issue New Insights into Amino Acid Biosynthesis)
►▼
Show Figures
Figure 1
Open AccessArticle
Inhibitory Effects of Ammonia on Archaeal 16S rRNA Transcripts in Thermophilic Anaerobic Digester Sludge
Fermentation 2023, 9(8), 728; https://doi.org/10.3390/fermentation9080728 - 04 Aug 2023
Abstract
High temperatures exacerbate the ammonia inhibition of anaerobic digestion coupled with methanogenesis. The inhibition of methane production by ammonia has been observed in other studies. However, the underlying mechanism is not well understood and requires further investigation. This study explored the effect of
[...] Read more.
High temperatures exacerbate the ammonia inhibition of anaerobic digestion coupled with methanogenesis. The inhibition of methane production by ammonia has been observed in other studies. However, the underlying mechanism is not well understood and requires further investigation. This study explored the effect of ammonia stress on archaeal 16S rRNA transcripts in thermophilic anaerobic digester sludge. Different ammonium concentrations were checked for their influence on the methanogenic rate and hydrogen accumulation. Quantitative PCR was used to compare the changes in total archaeal 16S rRNA expression. A Monte Carlo permutation test within redundancy analysis (RDA) was adopted for exploring the relationship between environmental variables and archaeal 16S rRNA and their transcripts. The results showed that with the increase in ammonium concentration, the methanogenic rate decreased and hydrogen accumulation occurred. The total archaeal 16S rRNA genes and transcripts copy numbers decreased significantly in treatments with higher ammonium concentrations (7 and 10 g NH4+-N/L), but did not change much at lower ammonia concentrations (3 g NH4+-N/L) compared with the 0 g NH4+-N/L treatment. The RDA analysis further revealed that most environmental variables, including ammonia and methane, except for formate, were significantly correlated with the community structure activity of archaeal 16S rRNA transcripts rather than the community structure of their genes. The composition of archaeal 16S rRNA transcripts showed that the hydrogenotrophic methanogen Methanothermobacter dominated the methanogenic community activity in all incubations. It exhibited sensitivity to ammonia stress and should be responsible for the methanogenic inhibition under thermophilic conditions. Our findings suggested that archaeal 16S rRNA transcripts, rather than 16S rRNA genes, are key indicators of ammonia stress and methanogenic activity.
Full article
(This article belongs to the Special Issue Progress of Anaerobic Digestion in Sewage Sludge Treatment)
►▼
Show Figures
Figure 1
Open AccessArticle
High Salt Concentration Affects the Microbial Diversity of Cassava during Fermentation, as Revealed by 16S rRNA Gene Sequencing
Fermentation 2023, 9(8), 727; https://doi.org/10.3390/fermentation9080727 - 03 Aug 2023
Abstract
Cassava plays an important role in the life and diet of several communities worldwide. It is used in various processed forms and has become the focus of research and innovation in recent years. Bioprocessing techniques, such as fermentation, have been utilized to create
[...] Read more.
Cassava plays an important role in the life and diet of several communities worldwide. It is used in various processed forms and has become the focus of research and innovation in recent years. Bioprocessing techniques, such as fermentation, have been utilized to create new avenues for its application in food and functional products. The fermentation of cassava can enhance its nutritional value, improve its shelf life, and increase its digestibility. However, the effect of salt-mediated fermentation on microbial diversity and potential benefits has not been widely reported. In this study, the effect of six levels of salt (NaCl), ranging from 0 to 25% after 50 days of spontaneous cassava fermentation at 25–30 °C, was investigated. A total of 30 bacterial isolates were selected for molecular characterization. A proprietary pool of universal 16S rRNA primers and species-specific primers were used to amplify a wide variety of species in clonal samples. The bacteria observed include Lactiplantibacillus, Limosilactobacillus, and Weissella. The population of Lactiplantibacillus in the cassava microflora increased with and without salt treatment, while Weissella, a new genus, was detected in 20 and 25% of salt-treated samples. Lactiplantibacillus and Weissella accounted for 32 and 68% and 60 and 40% of the bacterial populations detected at 20 and 25% salt treatment, respectively. A total of 17 strains and sequences were identified from the 30 isolates screened. Sequencing results classified the 30 isolates into four groups, of which 76.67% were Limosilactobacillus. Phylogenetic analysis showed that all 17 strains were divided into three clusters. These results show that high salt-mediated fermentation of cassava can trigger a shift in dominance in the bacterial community, changing the diversity of the microbial community.
Full article
(This article belongs to the Section Fermentation for Food and Beverages)
►▼
Show Figures
Figure 1
Open AccessArticle
Anaerobic Fermentation of Slaughterhouse Waste—Codigestion with Wheat Straw to Determine Methane Biochemical Potential and Kinetic Analysis
Fermentation 2023, 9(8), 726; https://doi.org/10.3390/fermentation9080726 - 02 Aug 2023
Abstract
Slaughterhouse solid waste is one of the sources of greenhouse gas (GHG) today. Crop residue decomposition or incineration has a great impact on global warming. Therefore, it is urgent to study the possibility of better environmentally friendly approaches to solid waste management and
[...] Read more.
Slaughterhouse solid waste is one of the sources of greenhouse gas (GHG) today. Crop residue decomposition or incineration has a great impact on global warming. Therefore, it is urgent to study the possibility of better environmentally friendly approaches to solid waste management and its safe disposal. The digestion of this type of solid waste in a decomposing process from organic content allows the recovery of valuable resources (such as biogas) and the use of the digestate in various fertilizer industries. In this study, two substrates were studied to determine their biomethane (BMP) potential in anaerobic digestion. The substrates were fermented and digested anaerobically and biogas production was measured. Methane yield of the slaughterhouse substrates had a lower methane yield between 232.2 and 250.8 mL/gVS and 53.6 to 57.9% biodegradability. Harvest substrates produce between 167.1 and 274.9 mL/gVS with a biodegradability of 39.1 to 64.3%. Co-digestion of both substrates at a ratio of IS 1:2 (RR:WS 3:1) generated a higher yield 289.1 ml/gVS and 66.9%. biodegradability of A kinetic analysis was carried out using Gompertz models, transfer and logistic function for methane production biodegradation.
Full article
(This article belongs to the Special Issue Application of Anaerobic Digestion in Waste Treatment and Valorization)
►▼
Show Figures
Figure 1
Open AccessArticle
Assessing the Potential of Milk-Based Encapsulation Matrix for Improved Bio-Accessibility of Probiotics
by
, , , , , , , , and
Fermentation 2023, 9(8), 725; https://doi.org/10.3390/fermentation9080725 - 01 Aug 2023
Abstract
Milk and sodium alginate beads (SA) as encapsulation materials can improve the viability of Lacticaseibacillus acidophilus LAC5. The present study focused on interactive structural optimization of milk and SA-based beads for improved survival of L. acidophilus LAC5 in cheddar cheese. L. acidophilus was
[...] Read more.
Milk and sodium alginate beads (SA) as encapsulation materials can improve the viability of Lacticaseibacillus acidophilus LAC5. The present study focused on interactive structural optimization of milk and SA-based beads for improved survival of L. acidophilus LAC5 in cheddar cheese. L. acidophilus was microencapsulated using varying concentrations of milk and SA, e.g., T0 (Milk/SA 0:0), T1 (Milk/SA 1/1:1), T2 (Milk/SA 1/2:1), T3 (Milk/SA 1/1:1.5), T4 (Milk/SA1/2:1.5), T5 (Milk/SA 1/1:2.0) and T6 (Milk/SA 1/2:2.0). Free and encapsulated L. acidophilus were compared for their survival in gastroenteric conditions. Structural and spectral analysis was performed using scanning electron microscope (SEM) and Fourier transform infrared spectrometry (FTIR). The free and encapsulated probiotics were incorporated into cheddar cheese. Organic acids were quantified using HPLC. The combination of SA and milk significantly (p < 0.05) improved the survival of L. acidophilus as compared to free cells. The increase in polymer concentration improved the structure of beads and the survival of probiotics. However, the release profile of beads decreased with the increase in polymer concentration. FTIR showed the presence of milk and SA in the beads. Better storage stability (108 CFU/mL) was observed for T6 in all the treatments as compared to free cells. The addition of encapsulated cells improved the sensory characteristics of cheese. This may help the local food industry to utilize native probiotic strains to be incorporated into probiotic foods with improved bio-accessibility.
Full article
(This article belongs to the Special Issue Probiotics and Prebiotics in Fermented Products)
►▼
Show Figures
Figure 1
Open AccessArticle
Structural Characterization with Laser Scanning Microscopy and an Analysis of Volatile Components Using GC-MS in Vanilla Pods Coated with Edible Microorganisms
Fermentation 2023, 9(8), 724; https://doi.org/10.3390/fermentation9080724 - 01 Aug 2023
Abstract
The aroma of vanilla pods is mainly derived from vanillin. Microbial biotransformation reactions of vanillin precursors yield “natural” vanillin-related aroma metabolites. In this study, we coated vanilla pods with three edible microorganisms and observed the changes in tissues with a laser scanning microscope
[...] Read more.
The aroma of vanilla pods is mainly derived from vanillin. Microbial biotransformation reactions of vanillin precursors yield “natural” vanillin-related aroma metabolites. In this study, we coated vanilla pods with three edible microorganisms and observed the changes in tissues with a laser scanning microscope during early curing. In addition, the conducted volatile components analysis using gas chromatography-mass spectrometry (GC-MS) with ethanol extracts to investigate the differences in the aroma components of coated and uncoated microbial vanilla pods and to identify the correlation between processing and the oily luster of pods. The results demonstrate that the oily luster on the surface of vanilla pods coated with Bacillus subtilis subsp. subtilis is one of the necessary conditions for a high-quality vanilla product. Eight categories of compounds were found in the ethanol extract of vanilla pods. A total of 69 volatile components were analyzed. Different microbial species significantly influenced the volatile components, with 31 compounds not found in the control group. Furthermore, 30 odor and aroma compounds were identified. This study reveals the role of edible microbial coatings in enhancing the natural aroma of vanilla pods and offers possibilities for the development of new and unique vanilla aroma profiles.
Full article
(This article belongs to the Special Issue Flavor and Aroma in the Fermented Food)
►▼
Show Figures
Graphical abstract
Open AccessArticle
Valorization of Mexican Rambutan Peel through the Recovery of Ellagic Acid via Solid-State Fermentation Using a Yeast
by
, , , , , and
Fermentation 2023, 9(8), 723; https://doi.org/10.3390/fermentation9080723 - 01 Aug 2023
Abstract
Rambutan (Nephelium lappaceum L.) is a tropical fruit that is originally from Southeast Asia and it was introduced to Mexico in the 1960s; the fruit’s peel is known to possess ellagitannins such as ellagic acid which give the peel great biological activity;
[...] Read more.
Rambutan (Nephelium lappaceum L.) is a tropical fruit that is originally from Southeast Asia and it was introduced to Mexico in the 1960s; the fruit’s peel is known to possess ellagitannins such as ellagic acid which give the peel great biological activity; solid-state fermentation has been used to obtain said compounds and rambutan peel can be used as a fermentation support/substrate; this work aims to obtain, identify and quantify ellagic acid obtained via SSF with a strain of yeast. The water-absorption index and the support’s maximum moisture were determined. To determine the ideal conditions for ellagic acid accumulation, a Box–Behnken 3k experimental design was applied using variables such as temperature, moisture and inoculum. The maximum accumulation time of ellagic acid via solid-state fermentation was determined to be 48 h with ideal conditions of 30 °C, 60% moisture and 1.5 × 107 cells/g using S. cerevisiae, and high-performance liquid chromatography was used to identify ellagic acid, geraniin and corilagin as the most abundant compounds. The maximum recovery of ellagic acid was 458 ± 44.6 mg/g. HPLC/ESI/MS analysis at 48 h fermentation showed biodegradation of geraniin and corilagin due to ellagic acid. Mexican rambutan peel has been demonstrated to be a suitable substrate for SSF.
Full article
(This article belongs to the Special Issue New Trends in Solid Fermentation)
►▼
Show Figures
Figure 1
Journal Menu
► ▼ Journal Menu-
- Fermentation Home
- Aims & Scope
- Editorial Board
- Topical Advisory Panel
- Instructions for Authors
- Special Issues
- Topics
- Sections & Collections
- Article Processing Charge
- Indexing & Archiving
- Editor’s Choice Articles
- Most Cited & Viewed
- Journal Statistics
- Journal History
- Journal Awards
- Conferences
- Editorial Office
Journal Browser
► ▼ Journal BrowserHighly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Agriculture, Applied Sciences, Fermentation, Foods, Molecules
New Concepts in Functional Food Product Development
Topic Editors: Aleksandra Szydłowska, Joanna Stadnik, Sylwia Ścieszka, Rubén DomínguezDeadline: 30 September 2023
Topic in
Agronomy, Fermentation, IJERPH, Soil Systems, Sustainability
Waste Management through Composting: Benefits, New Insights and Challenges
Topic Editors: Jorge Medina, Heike Knicker, Marcela Calabi-Floody, Humberto AponteDeadline: 30 November 2023
Topic in
Energies, Fermentation, Materials, Resources, Sustainability
Waste-to-Energy
Topic Editors: Jingxin Zhang, Le ZhangDeadline: 31 December 2023
Topic in
Beverages, Fermentation, Foods, Molecules, Separations
Advances in Analysis of Flavors and Fragrances: Chemistry, Properties and Applications in Food Quality Improvement
Topic Editors: Ana Leahu, Marìa Soledad Prats Moya, Cristina GhineaDeadline: 31 May 2024
Conferences
Special Issues
Special Issue in
Fermentation
Biofuels Production and Processing Technology 2.0
Guest Editor: Alessia TropeaDeadline: 20 August 2023
Special Issue in
Fermentation
Functional Foods and Probiotic Food Development: Trends, Concepts, and Products
Guest Editors: Sobhy Ahmad El-Sohaimy, Malik HussainDeadline: 31 August 2023
Special Issue in
Fermentation
Dark Fermentation for Biofuels and Chemical Building Blocks
Guest Editors: Rodolfo Palomo-Briones, Jorge Arreola-Vargas, Juan Ramírez-MoralesDeadline: 20 September 2023
Special Issue in
Fermentation
Anaerobic Fermentation and High-Value Bioproducts
Guest Editor: Yuriy LittiDeadline: 30 September 2023