Search Results (154)

Kombucha, a traditional fermented beverage, has become an important topic in global health beverage research due to its potential health benefits. The aim of this review is to integrate the existing literature and analyze the interactions among microbial communities during the fermentation process of kombucha, especially how Saccharomyces, Acetobacter, and Lactobacillus generate bioactive components with health benefits through the cascade reaction in sugar metabolism–ethanol oxidation–organic acid accumulation. We also focus on the effects of fermentation conditions (e.g., time, temperature, and strain) on the microbial community structure and metabolic pathways, as well as their effects on the bioactive components and quality of kombucha microbiota (the microbial community in kombucha). By combing and analyzing the existing studies, this review provides an important theoretical basis for the optimization of the fermentation process, enhancement of health benefits, and development of functional beverages of kombucha microbiota, as well as new ideas for future research directions. Full article

Lycopene (Lyc) possesses strong antioxidant activity through its ability to scavenge singlet oxygen and modulate immune responses in livestock and poultry. As few studies have examined the effects of Lyc on hepatic antioxidant capacity in broilers, we evaluated the effects of dietary Lyc supplementation on growth performance, antioxidant capacity, intestinal morphology, and microflora composition in yellow-feather broilers. We randomly assigned 480 one-day-old yellow-feather broilers to four dietary treatments: a basal diet with no additive (Con), and a basal diet supplemented with 150 mg/kg (Lyc150), 250 mg/kg (Lyc250), or 500 mg/kg (Lyc500) of lycopene. Compared to Con, Lyc supplementations significantly increased average daily gain by more than 14% from days 29 to 56. Additionally, Lyc250 significantly increased by over 6.4% in average daily feed intake from days 1 to 28, as well as by over 50% in hepatic levels of total antioxidant capacity and 65% in catalase on day 56. Lyc250 significantly increased villus height and decreased the villus-to-crypt ratio. Moreover, both Lyc250 and Lyc500 significantly downregulated hepatic Bax mRNA expression. Further, Lyc150 and Lyc250 significantly increased the relative abundance of Fermentum_g_Lactobacilus, Enterococcus_cecorum_g_Enterococcus, and Ruminococcus sp_g_Ruminococcus, but decreased Acetobacter_lovaniensis_g_Acetobacter and Lactobacillus_amylolyicus_g_Lactobacilus. Overall, our study found that Lyc supplementation significantly improved growth performance, enhanced hepatic antioxidant capacity, and modulated cecal microflora through increasing beneficial species in yellow-feather broilers. Full article

Olive mill wastewater is a by-product of olive oil extraction, characterized by a high concentration of organic matter, which presents a significant environmental challenge if not properly managed. This study was aimed at valorizing olive mill wastewater through selective fermentations to produce acetic beverages with low or no alcohol content. Olive mill wastewaters at three different dilutions (100%, 75% and 50%) were inoculated with Saccharomyces cerevisiae UMCC 855 for alcoholic fermentation. The resulting alcoholic product, with 75% olive mill wastewater, was then used as a substrate for acetic acid fermentation by Acetobacter pasteurianus UMCC 1754, employing both static and submerged acetification systems. The results showed that, at the end of the static acetification process, no residual ethanol was detected and that high concentrations of acetic and gluconic acid (46.85 and 44.87 g/L, respectively) were observed. In the submerged fermentation system, the final ethanol concentration was 24.74 g/L; the produced organic acids content reached 31.63 g/L of acetic acid and 39.90 g/L of gluconic acid. Furthermore, chemical analyses revealed that fermentation enhanced the antioxidant activity of olive mill wastewater. These results suggest promising insights for the valorization of olive mill wastewater. Full article

This study investigated changes in microbial communities and functional components during the fermentation of traditional Korean grain vinegars collected from various regions as well as the correlations among these components. Microbial community analysis revealed that Lactobacillus acetotolerans was the dominant microorganism, while Acetobacter pasteurianus numbers gradually increased during fermentation, playing a key role in acetic acid production. L. acetotolerans, known to thrive in acidic environments, contributed to increasing the acidity of the vinegar and enhanced its preservative properties. The rise in the levels of organic acids, particularly acetic acid, was influenced by the activity of these microorganisms. Additionally, the production of free amino acids, such as alanine, was influenced by interactions between the fermentation medium and microbial communities, significantly contributing to the vinegar’s sweetness. Volatile flavor compounds exhibited considerable diversity due to changes in microbial communities driven by raw-material differences. In particular, five-grain vinegar (YO) tended to generate more complex and intense flavor compounds, with uniformly elevated levels of aldehydes, acids, and ketones. These findings suggest that raw-material selection and fermentation conditions significantly influence the flavor and functional properties of grain vinegars, providing valuable foundational data for improving vinegar production processes to enhance flavor and functionality. Full article

The meat quality of sheep and goats differs even within the same age, gender, and farming systems. Intramuscular fat (IMF) content is an important factor affecting the quality of livestock meat because it affects muscle color, tenderness, juiciness, water-holding capacity, and flavor. This study evaluates the differences in IMF deposition characteristics between Longdong cashmere goats and Tan sheep, and also explores the correlations between these variations and the gut microbiota. The results revealed that the IMF contents in shoulder and rump meat, as well as the blood lipid levels, of Longdong cashmere goats were higher than those of Tan sheep (p < 0.05). The content of fatty acid synthase (FAS) in the duodenum of the goats was lower, but the content of hormone-sensitive lipase (HSL) in both the pancreas and duodenum was greater (p < 0.05). The Chao1 and β diversity showed differences between the two breeds, observed not only in the abomasum but also in the colon. The specific microbiota identified from the goats were involved in the lipid metabolism pathway. The concentrations of acetic acid and propionic acid in the colonic and abomasal chyme were decreased in the goats when compared to the sheep (p < 0.05). The contents of FAS in the colonic chyme of the goats were significantly lower, while HSL in the abomasal chyme was significantly higher than that of the sheep. The correlation analysis of IMF deposition with gut microbiota showed that Acetobacter and UBA1711 in the abomasum, as well as Faecousia, WQUU01, UBA5905, and GCA-900066495 in the colon, were positively correlated with the IMF content in shoulder meat and the level of LDL (except for UBA1711), but negatively associated with the content of propionic acid (|r| > 0.45, p < 0.05). This preliminary study has demonstrated that some specific bacteria in the abomasum and colon were associated with IMF deposition, while also providing an indicative reference range for further investigation into the effects of microbes on IMF deposition. Full article

Reducing the use of chemical inputs (fertilizers, pesticides) in agriculture while maintaining crop productivity is the main challenge facing sub-Saharan African family farming systems. The use of effective microorganisms (EM) is among the various innovative approaches for minimizing chemical inputs and the environmental impact of agricultural production and protecting soil health while enhancing crop yields and improving food security. This study sought to characterize the microbial biodiversity of local beneficial microorganisms (BMs) products from locally fermented forest litter and investigate their ability to enhance tomato plant growth and development. Beneficial microorganisms (BMs) were obtained by anaerobic fermentation of forest litter collected in four agroecological regions of Senegal mixed with sugarcane molasses and various types of carbon sources (groundnut shells, millet stovers, and rice bran in different proportions). The microbial community composition was analyzed using next-generation rDNA sequencing, and their effects on tomato growth traits were tested in greenhouse experiments. Results show that regardless of the litter geographical collection site, the dominant bacterial taxa in the BMs belonged to the phyla Firmicutes (27.75–97.06%) and Proteobacteria (2.93–72.24%). Within these groups, the most prevalent classes were Bacilli (14.41–89.82%), α-proteobacteria (2.83–72.09%), and Clostridia (0.024–13.34%). Key genera included Lactobacillus (13–65.83%), Acetobacter (8.91–72.09%), Sporolactobacillus (1.40–43.35%), and Clostridium (0.08–13.34%). Fungal taxa were dominated by the classes Leotiomycetes and Sordariomycetes, with a prevalence of the acidophilic genus Acidea. Although microbial diversity is relatively uniform across samples, the relative abundance of microbial taxa is influenced by the litter’s origin. This is illustrated by the PCoA analysis, which clusters microbial communities based on their litter source. Greenhouse experiments revealed that five BMs (DK-M, DK-G, DK-GM, NB-R, and NB-M) significantly (p < 0.05) enhanced tomato growth traits, including plant height (+10.75% for DK-G and +9.44% for NB-R), root length (+56.84–62.20%), root volume (+84.32–97.35%), root surface area (+53.16–56.72%), and both fresh and dry shoot biomass when compared to untreated controls. This study revealed that forest-fermented litter products (BMs), produced using litter collected from various regions in Senegal, contain beneficial microorganisms known as plant growth-promoting microorganisms (PGPMs), which enhanced tomato growth. These findings highlight the potential of locally produced BMs as an agroecological alternative to inorganic inputs, particularly within Senegal’s family farming systems. Full article

Mangifera indica L. by-products obtained by three extraction methods from three cultivars (Keitt, Sensation and Gomera-3) were tested for their antibacterial properties against 20 bacterial species. These species were selected based on their relevance to winemaking processes (Acetobacter, Gluconobacter and Gluconacetobacter), fermented meat products (Staphylococcus) and human diseases (Pseudomonas, Escherichia, Shigella and Klebsiella). All mango by-product extracts showed antimicrobial activity in agar diffusion and broth microdilution experiments. However, differences in antimicrobial activity against acetic acid bacteria were detected between the peel extracts obtained from the two extraction processes. Furthermore, a wide range of minimum inhibitory concentration (MIC) data were found; Staphylococcus spp. (10 species) showed MICs between 1.0–240 mgGAE/mL and Acetobacter spp. (4 species) showed MICs between 1.7 and 200 mgGAE/mL. The most sensitive bacteria belonged to the staphylococcal species (MIC: 1 mgGAE/mL) and the most resistant was Gluconacetobacter saccharivorans (MIC > 400 mgGAE/mL). In general, there was no significant correlation between the phenolic compounds identified and the MIC values. The minimum bactericidal concentration (MBC) revealed that the mango extracts had a bacteriostatic effect. A simple and reliable method for the determination of MIC and MBC in microdilution assays with acetic acid bacteria was described. These results highlight the antibacterial properties of mango by-products against species associated with food spoilage microorganisms and human diseases. Full article

Probiotic microorganisms from sugary kefir were incorporated into Brazilian non-alcoholic beers to enhance their functional and nutritional properties through aerobic static fermentation over 24 h. Non-alcoholic beers inoculated with sugary kefir showed appropriate acidity (pH reduction from ~3.74 to ~3.52), color, and microbial balance, along with excellent sensory acceptance (scores of 6.9–8.4 on a 9-point hedonic scale). The kefir microbiota included Lacticaseibacillus paracasei, Lacticaseibacillus casei, Lacticaseibacillus paracasei subsp. paracasei, Lacticaseibacillus paracasei subsp. tolerans, Lactobacillus delbrueckii subsp. lactis, Lentilactobacillus parabuchneri, Lentilactobacillus kefiri, Lactococcus lactis, Leuconostoc citreum, Acetobacter lovaniensis, and yeasts such as Saccharomyces cerevisiae, Kluyveromyces lactis, Lachancea meyersii, and Kazachstania aerobia. Genetic analysis confirmed the absence of undesirable or pathogenic microorganisms. Fermentation led to reductions in sucrose (~0.35 to ~0.22 g/L) and °Brix (~5.55 to ~3.80), with increases in lactic acid (~0.55 to ~1.25 g/L) and acetic acid (~0.08 to ~0.14 g/L), confirming active microbial metabolism. Ethanol levels remained within legal limits for non-alcoholic beverages. The process preserved sensory attributes while enriching the beverage with well-documented kefir microorganisms. These findings highlight sugary kefir as a promising biotechnological tool to enhance the functional profile of non-alcoholic beers without compromising their sensory quality. Full article

This study employed shotgun metagenomics to investigate microbial dynamics, phage-bacteria interactions, and functional genes throughout a three-month apple vinegar fermentation process. A total of 5621 microbial species were identified, revealing three distinct phases: (i) Enterobacteria and non-Saccharomyces species dominated the initial substrate; (ii) S. cerevisiae and Leuconostoc pseudomesenteroides prevailed in the intermediate phase; and (iii) acetic acid bacteria (Acetobacter ghanesis and Gluconobacter spp.), alongside non-Saccharomyces species (Pichia kudriavzevii and Malassezia restricta), dominated the final stages. Bacteriophage analysis revealed the presence of phages targeting spoilage bacteria, such as Pseudomonas and Erwinia, suggesting a role in regulating microbial stability and enhancing fermentation control. Functional metagenomic analysis highlighted key pathways associated with microbial growth and metabolite production, including carbohydrate and amino acid metabolism, energy production, and glycan biosynthesis. Enzymes involved in stress adaptation and secondary metabolism, including oxidative phosphorylation and phenolic compound synthesis, demonstrated microbial resilience and their potential role in shaping the product’s sensory and functional properties. Moreover, Enterobacteriaceae species were associated with pectin degradation during the early stages, aiding substrate breakdown. These findings are crucial for microbial and phage management in fermentation technology, offering valuable insights for innovation in the vinegar industry. Full article

The succession of microbial communities during the fermentation process in sesame-flavored Baijiu cellars profoundly influences the flavor profile of the liquor. However, the key factors driving microbial succession in these cellars remain unclear. This study focuses on the fermentation process of sesame-flavored Baijiu Zaopei in traditional Tongcheng cellars. Samples were collected from the surface, middle, and bottom of the cellar, categorized by fermentation time. Various techniques were employed to analyze the physicochemical properties (including moisture, ethanol, total acid, starch, and reducing sugars), flavor compounds (volatile substances and amino acids), and microbial communities (bacteria and fungi) of the Zaopei during fermentation. A total of 68 flavor compounds were detected, with 16 key flavor compounds and 16 amino acids identified. Microbiologically, the Lactobacillus genus dominated in the later stages of fermentation, while the Issatchenkia species were the predominant fungi. Correlation analysis indicated that environmental factors play a significant role in driving microbial community succession. Acetobacter, Staphylococcus, Pichia, Bacillus, and Kroppenstedtia species may contribute to the synthesis of key flavor compounds. The relative contents of acetic acid, 2-phenylethyl ester, and Benzenepropanoic acid ethyl ester were influenced by multiple microbial groups, suggesting a synergistic fermentation effect. PICRUSt2 predictions revealed significant differences in 41 KEGG pathways at level 2 and 293 pathways at level 3 across different fermentation intervals. These pathways are primarily associated with amino acid, ester, and nucleotide metabolism, as well as bacterial transcription, translation, and signal transduction. This research provides a theoretical foundation for understanding the fermentation mechanisms of sesame-flavored Baijiu. Full article

Microbial interactions are essential for maintaining the stability and functionality of microbiota in fermented foods. In this study, representative strains of predominant lactic acid bacteria and acetic acid bacteria in Sichuan bran vinegar were selected, and their interactions in a simulated solid-state fermentation system were investigated. The results reveal that the biomass of A. pasteurianus LA10 significantly increased in both the co-culture and the pure culture, whereas the biomass of L. amylovorus LL34 in the co-culture (6.44 ± 0.30 lg CFU/g) was significantly lower than that in the pure culture (7.28 ± 0.30 lg CFU/g) (p < 0.05), indicating a partially harmful symbiosis between these two strains. The metabolic analysis shows that total acid (21.82 mg/g) and acetic acid (9.53 mg/g) contents in the co-culture were lower than those in the pure culture of LA10, suggesting that LL34 inhibited the acid-producing activity of LA10 to some extent. The interaction between the two bacteria also influenced the production of volatile compounds and non-volatile compounds, as revealed by GC-MS and untargeted UHPLC-MS/MS, respectively. Significant enrichment of acid and amino acid metabolism pathways was observed in the co-culture, revealing the impact of bacterial interactions on flavor development. This study provides valuable insights into the advancement of vinegar brewing technology. Full article

The transformative effect of nanotechnology is revolutionizing medicine by introducing new therapeutic approaches. This study explores the utilization of aqueous extract from mushroom (Cortinarius sp.) used as a reducing agent to prepare zinc oxide myco-nanoparticles (ZnO-MNPs) in an eco-friendly manner. The synthesis of ZnO-MNPs has been confirmed by various characterization studies, including UV-vis spectroscopy, which revealed an absorption peak at 378 nm; X-ray diffraction (XRD) analysis, which revealed a wurtzite hexagonal structure; and Fourier transform infrared spectra (FTIR), which showed stabilizing agents around the ZnO-MNPs. The effectiveness of ZnO-MNPs as an anti-cancer agent was evaluated by monitoring liver biochemical parameters against hepatotoxicity caused by carbon tetrachloride (CCl₄) in Balb C mice. The results showed that the levels of catalase, glutathione (GSH), and total protein were significantly lower, while alanine aminotransferase (ALT), aspartate aminotransferase (ASAT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), melanin dialdehyde (MDA), and total bilirubin (TB) were significantly higher in each of the CCl₄ treatment groups. ZnO-MNP treatment significantly reduced the toxicological effects of CCl₄ but did not completely restore the accumulation. The antimicrobial efficacy of ZnO-MNPs was investigated and showed potential results against common pathogens, including Bacillus subtilis (29.05 ± 0.76), Bacillus meurellus (27.05 ± 0.5), Acetobacter rhizospherensis (23.36 ± 0.5), and Escherichia coli (25.86 ± 0.80), while antifungal activity was relatively lower. Moreover, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed that ZnO-MNPs are strong antioxidant agents. Overall, these findings highlight the effectiveness of myco-synthesized ZnO-NPs in combating pathogenic diseases, their promising role in cancer therapy, and their potential as a biomaterial option for future therapeutic applications. Full article

Fermented strains play a crucial role in shaping the physicochemical properties and functionality of fermented cow’s milk. The natural fermentation system demonstrates a certain degree of stability and safety after undergoing continuous domestication. Fermented mare’s milk has been consumed for its intestinal health benefits in regions such as Xinjiang and Inner Mongolia in China. This consumption is closely related to the fermented strains present. Consequently, from the perspective of fermented strains, this study aimed to compare the microbiota diversity of naturally fermented mare’s milk with that of inoculated fermented cow’s milk, using it as a fermentation system to develop new functional fermented cow’s milk products. Water retention, rheology, texture, pH, and titration acidity were analyzed to evaluate the quality of fermented cow’s milk with the obtained transmission strain system. Importantly, the correlation between the property of fermented cow’s milk and the diversity of fermentation system has been thoroughly analyzed. The findings indicate that the gel property of fermented cow’s milk is not directly linked to the strain diversity or the core strain of fermentation. Instead, the abundance of Lactobacillus, Lactococcus, Hafnia-Obesumbacterium, Leuconostoc, Acetobacter, and Acinetobacter bacteria significantly influences the quality of fermented cow’s milk. Consequently, this study has successfully developed a new type of fermented cow’s milk and provided a reliable theoretical foundation for the functional enhancement of specialized fermented cow’s milk products. Full article

Commercial tomato hybrids exhibit robust performance in modern high-input agricultural systems. However, their suitability for low-input farming remains uncertain. With the goal that by 2030, 25% of European agricultural production must be organic as part of the European Green Deal, this study aims to assess whether existing commercial tomato hybrids can offer a viable solution for low-input farming. Additionally, the impact of beneficial microorganisms such as plant growth-promoting rhizobacteria (PGPR), in relation to the growth and productivity of tomato hybrids under low-input cultivation is assessed. For this purpose, a well-defined microbial consortium, including Azotobacter chroococcum, Clostridium pasteurianum, Lactobacillus plantarum, Bacillus subtilis, and Acetobacter diazotrophicus, was applied as a liquid suspension to enhance root colonization and promote plant growth. Seven commercial tomatoes (Solanum lycopersicum L.) hybrids—the most popular in the Greek market—were evaluated for their performance under high-input (hydroponic) and low-input cultivation systems (with and without the use of PGPR). Several parameters related to yield, fruit quality, nutritional value, descriptive traits, and leaf elemental concentration were evaluated. In addition, a techno-economic analysis was conducted to assess whether hybrids developed under high-input conditions and intended for such cultivation environments suit low-input farming systems. The results indicated that such hybrids are not a viable, efficient, or profitable strategy for low-input cultivation. These findings underscore the importance of breeding tomato varieties, specifically adapted to low-input farming, highlighting the need for targeted breeding strategies to enhance sustainability and resilience in future agricultural systems. Notably, this study is among the first to comprehensively assess the response of commercial tomato hybrids under low-input conditions, addressing a critical gap in the current literature. Full article

Henan mung bean sour (HMBS) is the raw material for mung bean sour noodles (MBSNs), a traditional fermented food. To investigate the characteristic flavor compounds, we have detected the content of free amino acids (FAAs) and key metabolites including organic acids, sugars, and alcohols. The results revealed that the content associated with umami, sweetness, and bitterness (TVA > 1) showed significant differences. Metagenomic analysis indicated that Lactobacillus delbrueckii was the dominant and characteristic species in WJ and LY15, whereas Bifidobacterium mongoliense, Lactiplantibacillus plantarum, and Acetobacter indonesiensis were the dominant species in GY. The abundance of functional genes related to carbohydrate and amino acid metabolism was higher in WJ and LY15. There was a strong correlation between dominant genera and vital metabolites (r |>| 0.7). This study provides a theoretical foundation for the development of HMBS. Full article