Role In Fermentation Research Articles

The Role of Fermentation and Drying on the Changes in Bioactive Properties, Seconder Metabolites, Fatty Acids and Sensory Properties of Green Jalapeño Peppers

In this study, the influence of fermentation and different drying techniques on the bioactive components, antioxidant activity, phenolic components, fatty acids, nutrients and sensory characteristics of fresh and processed jalapeño peppers was investigated. At the end of the fermentation, the pH, acidity and salt values of the brine were determined as 3.38, 0.09% and 6.02 g/100 mL, respectively. The oil results of pepper samples were found between 2.0% (microwave and air) and 2.60% (oven). Total carotenoid and total phenolic amounts of fresh (control) and processed peppers (air, conventional, microwave and fermentation) were characterized to be between 3.38 (fermented) and 65.68 µg/g (air) to 45.81 (fermented) and 350.69 mg GAE/100 g (microwave), respectively. Total flavonoid quantities of fresh and processed pepper samples were defined to be between 14.17 (fresh) and 482.74 mg/100 g (microwave). 3,4-dihydroxybenzoic acid and catechin amounts in fresh and processed jalapeño peppers were defined to be between 0.43 (fermented) and 11.0 mg/100 g (microwave) to 1.36 (fermented) and 44.87 mg/100 g (microwave), respectively. The predominant fatty acids of pepper oils were palmitic, oleic and linoleic acid. The oleic acid amounts of fresh and processed jalapeño pepper oils were specified to be between 9.52% (air drying) and 29.77% (fermented), while the linoleic acid values of pepper oils vary between 10.84% (fermented) and 68.38% (air drying). The major elements of fresh and processed peppers were K, P, S, Ca, Mg, Fe and Zn in decreasing order. Protein amounts in fresh and processed jalapeño peppers were characterized to be between 8.59 (fermented) and 12.22% (oven). As a result of panelist evaluations, the most appreciated features (4.83 score) were the flavor, color and texture feature.

Assessment of Gut Microbiome Variations in the Mother and Twin Infant of Captive White-handed Gibbons (Hylobates lar) Reveals the Presence of Beneficial and Pathogenic Bacteria

The white-handed gibbon (Hylobates lar) is one of the three Hylobatidae species found in the Peninsular Malaysia region. Studies on primate gut microbiota have yet to be conducted in Malaysian Hylobatidae, but previous studies have covered Cercopithecidae. Knowledge of the gut microbiota of endangered captive Malaysian Hylobatidae primates is important for health assessment and conservation management. Thus, the main objective of this study was to determine the gut microbiota profile of captive white-handed gibbons using the metabarcode 16S rRNA gene. Two H. lar fecal samples collected from the mother and twin infant at Zoo Melaka were used for DNA extraction. Next-generation sequencing (NGS) of the 16S rRNA gene was performed. The NGS data were analyzed on the basis of amplicon sequence variation. The gut microbiota of H. lar was dominated by Firmicutes and Bacteroidota because of their important roles in fermentation and nutrient assimilation from plant-based food sources. Predominance of Prevotella in the gut microbiota of H. lar indicates that the captivity condition causes the gut microbiota of gibbons to resemble that of humans. Treponema, a pathogenic bacterium, was also detected in the mother and twin infant. Variation in the bacterial community profile between the mother and the infant indicated differences in dietary adaptations and physiological state. This study provides an overview of gibbon health levels through gut microbiome screening and can be used when considering Malaysian primate health welfare and captive management.

Efficient metabolic pathway modification in various strains of lactic acid bacteria using CRISPR/Cas9 system for elevated synthesis of antimicrobial compounds

Lactic acid bacteria (LAB) are known to exhibit various beneficial roles in fermentation, serving as probiotics, and producing a plethora of valuable compounds including antimicrobial activity such as bacteriocin-like inhibitory substance (BLIS) that can be used as biopreservative to improve food safety and quality. However, the yield of BLIS is often limited, which poses a challenge to be commercially competitive with the current preservation practice. Therefore, the present work aimed to establish an optimised two-plasmid CRISPR/Cas9 system to redirect the carbon flux away from lactate towards compounds with antimicrobial activity by disrupting lactate dehydrogenase gene (ldh) on various strains of LAB. The lactic acid-deficient (ldhΔ) strains caused a metabolic shift resulting in increased inhibitory activity against selected foodborne pathogens up to 78 % than the wild-type (WT) strain. The most significant effect was depicted by Enterococcus faecalis-ldh∆ which displayed prominent bactericidal effects against all foodborne pathogens as compared to the WT that showed no antimicrobial activity. The present work provided a framework model for economically important LAB and other beneficial bacteria to synthesise and increase the yield of valuable food and industrial compounds. The present work reported for the first time that the metabolism of selected LAB can be manipulated by modifying ldh to attain metabolites with higher antimicrobial activity.

Improving natto quality through Co-fermentation of functionally complementary Bacillus and Lactiplantibacillus species

Natto, a nutritious fermented soybean product, is known for its health benefits. Modern production methods use Bacillus subtilis as the starter culture to ensure consistent quality. However, this method overlooks the potential positive effects of other microbial species present in traditionally, naturally fermented natto. This study explored the effects of ARTP-induced mutants of B. subtilis var. natto and several strains of lactic acid bacteria (LAB) on natto quality. The results showed that these two types of bacteria have complementary roles in fermentation. B. subtilis var. natto, with enhanced extracellular protease activity, promotes the hydrolysis of soy protein and enhances the product's ACE inhibitory and fibrinolytic activities. Meanwhile, two strains of Lactiplantibacillus plantarum reduced the content of total volatile basic nitrogen (TVB-N) while increasing the content of folic acid in the final product. In addition, B. subtilis var. natto and LAB produce different profiles of volatile compounds (VOCs). Subsequently, B. subtilis var. natto and Lpb. plantarum were used to co-ferment natto in different ratios. The results showed that the two types of bacteria could co-colonize and enhance fermentation quality through their respective strengths. Specifically, Lpb. plantarum strains co-metabolized with B. subtilis var. natto to elevate the content of pyrazines, characteristic VOCs in natto. The optimal quality of natto was achieved when Lpb. plantarum HIS6, Lpb. plantarum LP3 and B. subtilis var. natto Y15-11 were combined in a 2:1:2 ratio. This study not only identified effective combinations of starter cultures with complementary benefits but also elucidated the metabolic pathways of key volatile compounds. Our findings also provide technical insights for improving natto quality, enhancing consumer acceptance, and supporting industrial production.

The role of fermentation with lactic acid bacteria in quality and health effects of plant-based dairy analogues.

The modern food industry is undergoing a rapid change with the trend of production of plant-based food products that are more sustainable and have less impact on nature. Plant-based dairy analogues have been increasingly popular due to their suitability for individuals with milk protein allergy or lactose intolerance and those preferring a plant-based diet. Nevertheless, plant-based products still have insufficient nutritional quality, undesirable structure, and earthy, green, and bean-like flavor compared to dairy products. In addition, most plant-based foods contain lesser amounts of essential nutrients, antinutrients limiting the bioavailability of some nutrients, and allergenic proteins. Novel processing technologies can be applied to have a homogeneous and stable structure. On the other hand, fermentation of plant-based matrix with lactic acid bacteria can provide a solution to most of these problems. Additional nutrients can be produced and antinutrients can be degraded by bacterial metabolism, thereby increasing nutritional value. Allergenic proteins can be hydrolyzed reducing their immunoreactivity. In addition, fermentation has been found to reduce undesired flavors and to enhance various bioactivities of plant foods. However, the main challenge in the production of fermented plant-based dairy analogues is to mimic familiar dairy-like flavors by producing the major flavor compounds other than organic acids, yielding a flavor profile similar to those of fermented dairy products. Further studies are required for the improvement of the flavor of fermented plant-based dairy analogues through the selection of special microbial cultures and formulations.

Recent Progress in the Role of Fermentation in Plant-Based Foods: A Concise Review

The global food industry is experiencing a transformative shift towards alternative foods driven by sustainability concerns and evolving consumer preferences. This paper explores fermentation's pivotal role in shaping the landscape of alternative foods, exploring its historical significance, fundamental principles, and contemporary applications.

Anaerobic Conversion of Proteinogenic Amino Acids When Methanogenesis Is Inhibited: Carboxylic Acid Production from Single Amino Acids

Proteins are an abundant biopolymer in organic waste feedstocks for biorefining. When degraded, amino acids are released, but their fate in non-methanogenic microbiomes is not well understood. The ability of a microbiome obtained from an anaerobic digester to produce volatile fatty acids from the twenty proteinogenic amino acids was tested using batch experiments. Batch tests were conducted using an initial concentration of each amino acid of 9000 mg COD L−1 along with 9000 mg COD L−1 acetate. Butyrate production was observed from lysine, glutamate, and serine fermentation. Lesser amounts of propionate, iso-butyrate, and iso-valerate were also observed from individual amino acids. Based on 16S rRNA gene amplicon sequencing, Anaerostignum, Intestimonas, Aminipila, and Oscillibacter all likely play a role in the conversion of amino acids to butyrate. The specific roles of other abundant taxa, including Coprothermobacter, Fervidobacterium, Desulfovibrio, and Wolinella, remain unknown, but these genera should be studied for their role in fermentation of amino acids and proteins to VFAs.

Genome analysis of Hanseniaspora vineae CC-P5 and CC-ZZ6 isolate from grapes reveals the biotech potential for winemaking

The genus Hanseniaspora is a non-Saccharomyces yeast frequently isolated from wine-associated environments and has been recognized to play a key role in winemaking. However, most of the research on Hanseniaspora focused on its role in fermentation or its coordination with Saccharomyces cerevisiae, but the genome data of Hanseniaspora is very scarce, which is not conducive to better utilization and development of this yeast. Therefore, in this study, the genome data of two Hanseniaspora vineae strains CC-P5 and CC-ZZ6 with flocculation and antimicrobial abilities were sequenced and bioinformatics analyses were performed. The results showed that the genomes of the two strains have a high degree of homology with an average nucleotide identity of 97.7 %. Both H. vineae CC-P5 and CC-ZZ6 have corresponding genes for adaptability to osmotic stress, sulfur dioxide stress, ethanol toxicity and other stresses, as well as various genes involved in the biosynthesis of ethyl esters, volatile organic acids, aromatic amino acid, benzyl alcohol/benzaldehyde and terpenoid, which are useful for modulating wine flavor and aroma. These results shed light on why H. vineae has the biotechnology to make wine. In addition, the number of publicly available H. vineae genome databases have increased. This has laid the foundation for further research on Hanseniaspora.

Microbial communities, functional, and flavor differences among three different-colored high-temperature Daqu: A comprehensive metagenomic, physicochemical, and electronic sensory analysis

High-temperature Daqu (HTD) is the starter for producing sauce-flavor Baijiu, with different-colored Daqu (white, yellow, and black) reflecting variations in fermentation chamber conditions, chemical reactions, and associated microbiota. Understanding the relationship between Daqu characteristics and flavor/taste is challenging yet vital for improving Baijiu fermentation. This study utilized metagenomic sequencing, physicochemical analysis, and electronic sensory evaluation to compare three different-colored HTD and their roles in fermentation. Fungi and bacteria dominated the HTD-associated microbiota, with fungi increasing as the fermentation temperature rose. The major fungal genera were Aspergillus (40.17%) and Kroppenstedtia (21.16%), with Aspergillus chevalieri (25.65%) and Kroppenstedtia eburnean (21.07%) as prevalent species. Microbial communities, functionality, and physicochemical properties, particularly taste and flavor, were color-specific in HTD. Interestingly, the microbial communities in different-colored HTDs demonstrated robust functional complementarity. White Daqu exhibited non-significantly higher α-diversity compared to the other two Daqu. It played a crucial role in breaking down substrates such as starch, proteins, hyaluronic acid, and glucan, contributing to flavor precursor synthesis. Yellow Daqu, which experienced intermediate temperature and humidity, demonstrated good esterification capacity and a milder taste profile. Black Daqu efficiently broke down raw materials, especially complex polysaccharides, but had inferior flavor and taste. Notably, large within-group variations in physicochemical quality and microbial composition were observed, highlighting limitations in color-based HTD quality assessment. Water content in HTD was associated with Daqu flavor, implicating its crucial role. This study revealed the complementary roles of the three HTD types in sauce-flavor Baijiu fermentation, providing valuable insights for product enhancement.

Diversity of fungi and dynamics of ethanol concentration during fermentation of porang (Amorphophallus oncophyllus)

Abstract. Helmi H, Kusmiadi R, Mahardika RG, Karsiningsih E. 2024. Diversity of fungi and dynamics of ethanol concentration during fermentation of porang (Amorphophallus oncophyllus). Biodiversitas 25: 542-552. Fermentation can be an alternative to process porang (Amorphophallus oncophyllus). As one of the fermentation products, ethanol can degrade starch and consequently increase the purity of glucomannan in porang flour. However, ethanol can also inhibit the growth of microorganisms that play a role in fermentation. This study aimed to determine the ethanol concentration and investigate the fungal diversity during the fermentation of porang tubers. Ethanol analysis was analyzed by Headspace Gas Chromatography coupled with flame ionization detection, and Starch content was analyzed by colorimetric method. Fungal metagenome was amplified at the Internal transcribed spacer (ITS) region of nuclear DNA (rDNA) and followed by sequencing using Oxford Nanopore Technology (ONT). The result showed that the ethanol concentration increased during 48 hours of fermentation, followed by decreased starch content. The highest fungal diversity index occurred at 48 hours of fermentation. Ethanol and fungal enzymatic activity can degrade the starch. During fermentation, the Candida parapsilosis population increased until 24 hours after fermentation. Cyberlindnera subsufficiens population increased at 48 hours fermentation until 72 hours fermentation. Fungal diversity and ethanol concentration had decreased at 72 hours of fermentation, so porang fermentation should be stopped at 48 hours. Candida parapsilosis could be the candidate of starter for fermentation porang due to the capability of this species to produce ethanol to degrade starch.

Microbiological and chemical characteristics of porkfish inasua, traditional fish fermented from Maluku, Indonesia

Abstract. Mahulette F. 2023. Microbiological and chemical characteristics of porkfish inasua, traditional fish fermented from Maluku, Indonesia. Biodiversitas 25: 1-8. Porkfish inasua consisted of two types, i.e., with and without coconut sap. The research aimed to analyze the microbiological and chemical characteristics of two types of porkfish inasua. The microbiological characteristics are used to determine the role of microbes and product safety whereas the chemical characteristics, including proximate composition, amino acids, and fatty acids contents can determine the nutritional value for consumption. The sample of porkfish inasua was taken from traditional producers in Layeni, Teon, Nila, and Serua (TNS) Islands, Maluku, Indonesia. The microbiological analysis was done using the plate count method. From the measurement, the total number of halotolerant and coliform bacterial in porkfish inasua without sap were 6.2 log cfu/g and 6.1 log cfu/g, respectively. In comparison, the total of Bacillus and related genera in porkfish inasua with sap was 5.9 log cfu/g at the end of fermentation. The fat content of both types of inasua was around 17%. The total amino acids and fatty acids contents of porkfish inasua without sap at the end of fermentation were 15.31 and 57.08%, while porkfish inasua with sap were 15.85 and 63.81%, respectively. The dominant bacteria found in porkfish inasua without sap was Staphylococcus saprophyticus, while porkfish inasua with sap was Bacillus cereus. These two bacteria play a role in fermentation so porkfish inasua was safe for consumption. Generally, chemical characteristics of porkfish inasua with sap were better than those of porkfish inasua without sap, but statistically, it was not significantly different. This research can improve the quality of porkfish inasua as local fermented fish products in Maluku.

Intermittent proton bursts of single lactic acid bacteria.

Lactic acid bacteria are a kind of probiotic microorganisms that efficiently convert carbohydrates to lactic acids, thus playing essential roles in fermentation and food industry. While conventional wisdom often suggests continuous release of protons from bacteria during acidification, here we developed a methodology to measure the dynamics of proton release at the single bacteria level, and report on the discovery of a proton burst phenomenon, i.e., the intermittent efflux of protons, of single Lactobacillus plantarum bacteria. When placing an individual bacterium in an oil-sealed microwell, efflux and accumulation of protons consequently reduced the pH in the confined extracellular medium, which was monitored with fluorescent pH indicators in a high-throughput and real-time manner. In addition to the slow and continuous proton release behavior (as expected), stochastic and intermittent proton burst events were surprisingly observed with a typical timescale of several seconds. It was attributed to the regulatory response of bacteria by activating H+-ATPase to compensate the stochastic and transient depolarizations of membrane potential. These findings not only revealed an unprecedented proton burst phenomenon in lactic acid bacteria, but also shed new lights on the intrinsic roles of H+-ATPase in membrane potential homeostasis, with implications for both fermentation industry and bacterial electrophysiology.

- Invited Review - Hydrogen production and hydrogen utilization in the rumen: key to mitigating enteric methane production.

Molecular hydrogen (H2) and formate (HCOO-) are metabolic end products of many primary fermenters in the rumen ecosystem. Both play a vital role in fermentation where they are electron sinks for individual microbes in an anaerobic environment that lacks external electron acceptors. If H2 and/or formate accumulate within the rumen, the ability of primary fermenters to regenerate electron carriers may be inhibited and microbial metabolism and growth disrupted. Consequently, H2- and/or formate-consuming microbes such as methanogens and possibly homoacetogens play a key role in maintaining the metabolic efficiency of primary fermenters. There is increasing interest in identifying approaches to manipulate the rumen ecosystem for the benefit of the host and the environment. As H2 and formate are important mediators of interspecies interactions, an understanding of their production and utilization could be a significant starting point for the development of successful interventions aimed at redirecting electron flow and reducing methane emissions. We conclude by discussing in brief ruminant methane mitigation approaches as a model to help understand the fate of H2 and formate in the rumen ecosystem.

Getting to the roots of metabolism: the role of fermentation in aerobic conditions in maize root tissues

Getting to the roots of metabolism: the role of fermentation in aerobic conditions in maize root tissues

Microbial Diversity and Functional Potential of Keem: A Traditional Starter Culture for Alcoholic Beverage-Application of Next-Generation Amplicon and Shotgun Metagenome Sequences.

"Pakhoi" is an ethnic drink of the Tons valley, Uttarakhand, India produced by fermenting jaggery and barley with the help of a starter culture called "keem". In the present study, we investigated the microbial diversity and associated functional potential of "keem" using shotgun metagenome sequencing and amplicon sequencing. We also compared the taxonomic data obtained using these two sequencing techniques. The results showed that shotgun sequencing revealed a higher resolution of taxonomic profiling as compared to the amplicon sequencing. Furthermore, it was found that the genera detected by shotgun sequencing were valuable for facilitating the fermentation process. Additionally, to understand the functional profiling of the genera, different databases were used for annotation, resulting in a total of 13 metabolic pathways. The five most abundant KEGG functions were genetic information processing, metabolism, translation, cofactor and vitamin metabolism and xenobiotic degradation. In contrast, the top five COG were in order of highest frequency sequences belonging to transcription, followed by general function prediction, carbohydrate transport metabolism, amino acid transport and metabolism and translation and biogenesis. Gene ontology revealed many pathways, biochemical processes and molecular functions associated with the organisms forming the starter culture. Overall, the present study can help to understand the microbial diversity and its role in fermentation of traditional alcoholic beverages using "Keem".

Spatial and temporal distribution of environmental microbiota in Chinese rice wine (Huangjiu) natural fermentation wineries

Huangjiu brewing workshop is a small ecosystem with complex microbial community growth. This micro ecosystem is the main provider of microorganisms in the process of Huangjiu fermentation. Its existence may greatly affect the quality and flavor of Huangjiu. Environmental microbial communities of the same brewing workshop in different historical periods were collected. Full-length High-throughput sequencing and Source Tracker were used to study the correlation between brewing raw materials, fermented mash and brewing environment, and to explore the involvement of environmental microorganisms in the fermentation process. The resident functional fungi in fermented Huangjiu mash were the main components of the fungal community detected in the environment. The wheat koji, tool and interior environment contributed greatly to the source of fermented fungi in Huangjiu. Compared with the bacterial community, the environmental origin of the fungal community in fermented mash was clearer. For bacteria, the increased contribution of community aggregation was attributed to the role of deterministic processes, and community structure became more stable, showing its unique role in fermentation. This study could be implemented in a more abundant natural fermentation environment, which was of great significance to control the natural fermentation process of Huangjiu.

Characterization of the Rhizosphere Bacterial Microbiome and Coffee Bean Fermentation in the Castillo-Tambo and Bourbon Varieties in the Popayán-Colombia Plateau

BackgroundThe microbial biodiversity and the role of microorganisms in the fermentation of washed coffee in Colombia were investigated using the Bourbon and Castillo coffee varieties. DNA sequencing was used to evaluate the soil microbial biota and their contribution to fermentation. The potential benefits of these microorganisms were analyzed, including increased productivity and the need to understand the rhizospheric bacterial species to optimize these benefits.MethodsThis study used coffee beans for DNA extraction and 16 S rRNA sequencing. The beans were pulped, samples were stored at 4ºC, and the fermentation process was at 19.5ºC and 24ºC. The fermented mucilage and root-soil samples were collected in duplicate at 0, 12, and 24 h. DNA was extracted from the samples at a concentration of 20 ng/µl per sample, and the data obtained were analyzed using the Mothur platform.ResultsThe study demonstrates that the coffee rhizosphere is a diverse ecosystem composed primarily of microorganisms that cannot be cultured in the laboratory. This suggests that the microbial community may vary depending on the coffee variety and play an essential role in fermentation and overall coffee quality.ConclusionsThe study highlights the importance of understanding and optimizing the microbial diversity in coffee production, which could have implications for the sustainability and success of coffee production. DNA sequencing techniques can help characterize the structure of the soil microbial biota and evaluate its contribution to coffee fermentation. Finally, further research is needed to fully understand the biodiversity of coffee rhizospheric bacteria and their role.

Quality characteristics of soybean fermented by Mucor, Rhizopus, and Aspergillus from meju

Three candidate starter strains—Aspergillus oryzae SNU-G, Mucor sp. KACC 46077, and Rhizopus oryzae KACC 40256—were inoculated into soybean, as individual strains or in combination, to assess their roles in fermentation. All the strains increased the pH, amino-type nitrogen, and moisture content of the soybean during fermentation, and decreased the lightness, redness, and yellowness. The inoculated strains increased to an average density of 1.37 × 108 spores/g (from the initial 5.0 × 107 spores/g) after 20 days of fermentation. Forty-two volatile compounds, including an acid, alcohols, carbonyls, furans, and a pyrazine, were more abundant in soybean fermented with starters than in controls. A. oryzae SNU-G increased the pH more than the other strains and produced more volatile alcohol compounds. R. oryzae KACC 40256 resulted in the lowest reduction of redness and yellowness during the fermentation and produced large amounts of carbonyl compounds, including two specific volatile compounds, 2-hydroxy-3-methylcyclopent-2-en-1-one and (3E)-3-ethyl-2-methylhexa-1,3-diene. Mucor sp. KACC 46077 contributed the least to pH change and volatile compound production, and did not produce specific volatile compounds. Although no significant synergy in the production of volatile compounds was found when using mixtures of strains compared with application of single strains, the quality of fermented soybeans was confirmed to be different depending on the strain(s) applied.

Role of fermentation and microbes in cacao fermentation and their impact on cacao quality

Cocoa seed fermentation involves a well-stabilized succession of microbial processes and the action of enzymes. Microorganisms (yeast, lactic acid bacteria, and acetic acid bacteria) play a critical role in cacao fermentation by degrading mucilage pulp by producing a stabilized succession of enzymatic reactions that contribute to its quality. Nowadays, the majority of cacao fermentation practiced in our planet is in the traditional form to produce aroma flavor. The art of using starter culture to substitute naturally occurring microorganisms in cacao fermentation is crucial for the development of the aroma and flavor of cacao for sustainable uniformity and quality improvement and unique cacao flavor development. In this sense, this review presents an overview of cacao fermentation process and its impacts on quality, starter culture and microorganisms involved in cacao fermentation process, cacao bioactive compounds and its health benefits. Moreover, the research perspectives needed and the advance made in terms of fermentation process in order to reduce fermentation period are reviewed.

Exploring the role of Sichuan Baoning vinegar microbiota and the association with volatile flavor compounds at different fermentation depths.

Cereal vinegar is usually produced through solid-state fermentation, and the microbial community plays an important role in fermentation. In this study, the composition and function of Sichuan Baoning vinegar microbiota at different fermentation depths were evaluated by high-throughput sequencing combined with PICRUSt and FUNGuild analysis, and variations in volatile flavor compounds were also determined. The results revealed that no significant differences (p > 0.05) were found in both total acid content and pH of vinegar Pei collected on the same day with different depths. There were significant differences between the bacterial community of samples from the same day with different depths at both phylum and genus levels (p < 0.05), however, no obvious difference (p > 0.05) was observed in the fungal community. PICRUSt analysis indicated that fermentation depth affected the function of microbiota, meanwhile, FUNGuild analysis showed that there were variations in the abundance of trophic mode. Additionally, differences in volatile flavor compounds were observed in samples from the same day with different depths, and significant correlations between microbial community and volatile flavor compounds were observed. The present study provides insights into the composition and function of microbiota at different depths in cereal vinegar fermentation and quality control of vinegar products.