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Microbial community analysis is an important field to study the composition and function of microbial communities. Microbial species annotation is crucial to revealing microorganisms' complex ecological functions in environmental, ecological and host interactions. Currently, widely used methods can suffer from issues such as inaccurate species-level annotations and time and memory constraints, and as sequencing technology advances and sequencing costs decline, microbial species annotation methods with higher quality classification effectiveness become critical. Therefore, we processed 16S rRNA gene sequences into k-mers sets and then used a trained DNABERT model to generate word vectors. We also design a parallel network structure consisting of deep and shallow modules to extract the semantic and detailed features of 16S rRNA gene sequences. Our method can accurately and rapidly classify bacterial sequences at the SILVA database's genus and species level. The database is characterized by long sequence length (1500 base pairs), multiple sequences (428,748 reads) and high similarity. The results show that our method has better performance. The technique is nearly 20% more accurate at the species level than the currently popular naive Bayes-dominated QIIME 2 annotation method, and the top-5 results at the species level differ from BLAST methods by <2%. In summary, our approach combines a multi-module deep learning approach that overcomes the limitations of existing methods, providing an efficient and accurate solution for microbial species labeling and more reliable data support for microbiology research and application.
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Aprendizado Profundo , Microbiota , RNA Ribossômico 16S/genética , Teorema de Bayes , Microbiota/genética , Bactérias/genética , FilogeniaRESUMO
Hydrolytic enzymes are essential components in second-generation biofuel technology and food fermentation processes. Nanozymes show promise for large-scale industrial applications as replacements for natural enzymes due to their distinct advantages. However, there remains a research gap concerning glycosidase nanozymes. In this study, a Zn-based single-atom nanozyme (ZnN4-900) is developed for efficient glycosidic bond hydrolysis in an aqueous solution. The planar structure of the class-porphyrin N4 material approximatively mimicked the catalytic centers of natural enzymes, facilitating oxidase-like (OXD-like) activity and promoting glycosidic bond cleavage. Theoretical calculations show that the Zn site can act as Lewis acids, attacking the CâO bond in glycosidic bonds. Additionally, ZnN4-900 has the ability to degrade starch and produce reducing sugars that increased yeast cell biomass by 32.86% and ethanol production by 14.56%. This catalyst held promising potential for enhancing processes in ethanol brewing and starch degradation industries.
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Bacteriophages have been used across various fields, and the utilization of CRISPR/Cas-based genome editing technology can accelerate the research and applications of bacteriophages. However, some bacteriophages can escape from the cleavage of Cas protein, such as Cas9, and decrease the efficiency of genome editing. This study focuses on the bacteriophage T7, which is widely utilized but whose mechanism of evading the cleavage of CRISPR/Cas9 has not been elucidated. First, we test the escape rates of T7 phage at different cleavage sites, ranging from 10 -2 to 10 -5. The sequencing results show that DNA point mutations and microhomology-mediated end joining (MMEJ) at the target sites are the main causes. Next, we indicate the existence of the hotspot DNA region of MMEJ and successfully reduce MMEJ events by designing targeted sites that bypass the hotspot DNA region. Moreover, we also knock out the ATP-dependent DNA ligase 1. 3 gene, which may be involved in the MMEJ event, and the frequency of MMEJ at 4. 3 is reduced from 83% to 18%. Finally, the genome editing efficiency in T7 Δ 1. 3 increases from 20% to 100%. This study reveals the mechanism of T7 phage evasion from the cleavage of CRISPR/Cas9 and demonstrates that the special design of editing sites or the deletion of key gene 1. 3 can reduce MMEJ events and enhance gene editing efficiency. These findings will contribute to advancing CRISPR/Cas-based tools for efficient genome editing in phages and provide a theoretical foundation for the broader application of phages.
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Bacteriófago T7 , Sistemas CRISPR-Cas , Edição de Genes , Edição de Genes/métodos , Bacteriófago T7/genética , DNA Ligases/genética , DNA Ligases/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Genoma ViralRESUMO
A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterial strain, designated ZS110521T, was isolated from high-temperature Daqu, a starter for production of Chinese Jiang-flavour Baijiu and was characterised by polyphasic taxonomy. This novel isolate grew in the presence of 0-20â% (w/v) NaCl, at pH 6.0-9.0 and 20-50 °C; optimum growth was observed with 8-10â% (w/v) NaCl, at pH 7.0 and 37 °C. A comparative analysis of the 16S rRNA gene sequence (1460 bp) of ZS110521T revealed that it displayed the highest similarity to Lentibacillus populi WD4L-1T (95.5â%), followed by Lentibacillus garicola SL-MJ1T (95.4â%) and Lentibacillus lacisalsi BH260T (95.2â%). ANI and dDDH values between ZS110521T and other strains of species of the genus Lentibacillus were less than 78 and 28â%, respectively. The predominant cellular fatty acids (> 10â%) of ZS110521T were anteiso-C17â:â0 (37.8â%), anteiso-C15â:â0 (28.1â%) and iso-C16â:â0 (15.5â%). The respiratory quinone was identified as menaquinone-7 (MK-7) and the major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The polyphasic taxonomic data and the results of chemotaxonomic analysis confirmed that ZS110521T represents a novel species, for which the name Lentibacillus daqui sp. nov. is proposed. The type strain of this proposed species is ZS110521T (=CGMCC 1.19456T =JCM 35213T).
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Bebidas Alcoólicas , Bacillaceae , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura , Bebidas Alcoólicas/microbiologia , Bacillaceae/classificação , Bacillaceae/isolamento & purificaçãoRESUMO
A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterial strain, designated ZS111008T, was isolated from high-temperature Daqu, a starter for production of Chinese Jiang-flavour Baijiu, and was characterized by polyphasic taxonomy. This novel isolate grew in the presence of 0-5â% (w/v) NaCl, at pH 6.0-9.0 and 25-45â°C; optimum growth was observed with 1â% (w/v) NaCl, at pH 8.0 and 30â°C. A comparative analysis of the 16S rRNA gene sequence (1461 bp) of strain ZS111008T showed highest similarity to Solibacillus silvestris DSM12223T (96.7%), followed by Solibacillus cecembensis PN5T (96.6%) and Solibacillus isronensis AMCK01000046 (96.5%). The DNA G+C content of strain ZS111008T was 37.21 mol%. The respiratory quinone was identified as menaquinone-7 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and one unknown phospholipid. Lys was detected as the diagnostic diamino acid in the cell wall. Based on morphological characteristics, chemotaxonomic characteristics and physiological properties, strain ZS111008T represents a novel species of the genus Solibacillus, for which the name Solibacillus daqui sp. nov. is proposed. The type strain for this proposed species is ZS111008T (=CGMCC 1.19455T=JCM 35214T).
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Ácidos Graxos , Cloreto de Sódio , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Temperatura , Filogenia , DNA Bacteriano/genética , Composição de Bases , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , Fosfolipídeos/química , ChinaRESUMO
Daqu is the natural starter for Nong-flavor Baijiu brewing. The effects of Daqu properties on the microbial community succession and their metabolites in fermented grains (FG) during Baijiu brewing were determined. These results showed that the effect of Daqu on the bacterial communities was stronger than that of the fungal communities. Compared with the conventional Daqu (DZ), Taikong (TK), and Qianghua (QH), Daqu significantly enhanced the content of volatile metabolites (especially esters) and ethanol when they were used, respectively, for FG fermentation. In the second round of fermentation, the relative abundance of Lactobacillus decreased, the content of lactic acid decreased, and that of caproic acid increased. In particular, the abundance of Lactobacillus was also reduced by 20% in FGs of the second round when TK Daqu was used than that in the respective first round. Partial least squares structural equation model analysis also showed that physicochemical parameters and Daqu properties significantly affected FG community structure and metabolism. This study provides a theoretical basis for further study on the effect of high-quality Daqu on the quality of fresh Baijiu and lays an important theoretical foundation for the stabilization of the Baijiu fermentation system based on Daqu.
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Bebidas Alcoólicas , Microbiota , Fermentação , Bebidas Alcoólicas/microbiologia , Bactérias/metabolismo , Etanol/análise , Etanol/metabolismo , LactobacillusRESUMO
Accurate measurements of the bubble size distribution (BSD) are crucial for investigating gas-liquid mass transfer mechanisms and describing the characteristics of chemical production. However, measuring the BSD in high-density bubbly flows remains challenging due to limited image algorithms and high data densities. Therefore, an end-to-end BSD detection method in dense bubbly flows based on deep learning is proposed in this paper. The bubble detector locates the positions of dense bubbles utilizing objection detection networks and simultaneously performs ellipse parameter fitting to measure the size of the bubbles. Different You Only Look Once (YOLO) architectures are compared, and YOLOv7 is selected as the backbone network. The complete intersection over union calculation method is modified by the circumferential horizontal rectangle of bubbles, and the loss function is optimized by adding L2 constraints of ellipse size parameters. The experimental results show that the proposed technique surpasses existing methods in terms of precision, recall, and mean square error, achieving values of 0.9871, 0.8725, and 3.8299, respectively. The proposed technique demonstrates high efficiency and accuracy when measuring BSDs in high-density bubbly flows and has the potential for practical applications.
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BACKGROUND: The feasibility of fortification techniques to improve the quality of medium-temperature Daqu (MTD) by inoculation functional isolates has been demonstrated. However, it is unclear what is the effect of inoculation on the controllability during the MTD fermentation process. Here, inoculated a single strain of Bacillus licheniformis, and the microbiota composed of Bacillus velezensis and Bacillus subtilis, were used to investigate the synergistic effect of biotic and abiotic factors on the succession and assembly of the MTD microbiota during the process. RESULTS: The biotic factors promoted the proliferation of microorganisms that arrived early at the MTD. Subsequently, this alteration might inhibit microorganisms that colonized later in the MTD microecosystem, thereby assembling a different but more stable microbial community. Moreover, the biotic factors making bacterial community assembly were dominated by variable selection earlier, whereas the fungal community assembly was dominated mainly by extreme abiotic factors rather than biotic factors. Interestingly, fermentation temperature and moisture were significantly associated with the succession and assembly of the fortified MTD community. Meanwhile, the effect of the environmental variables on endogenous variables was also significant. Thus, changes in endogenous variables could be mitigated by adjusting environmental variables to regulate the process of MTD fermentation. CONCLUSION: Biotic factors cause rapid changes of the microbiota during the MTD fermentation process, which could be controlled indirectly by regulating environmental variables. Meanwhile, a more stable MTD ecological network might be beneficial for enhancing the stability of MTD quality. © 2023 Society of Chemical Industry.
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Bacillus licheniformis , Microbiota , Temperatura , Fermentação , Bacillus subtilisRESUMO
Traditional fermented alcoholic beverages (TFABs) have gained widespread acceptance and enjoyed great popularity for centuries. COVID-19 pandemics lead to the surge in health demand for diet, thus TFABs once again attract increased focus for the health benefits. Though the production technology is quite mature, food companies and research institutions are looking for transformative innovation in TFABs to make healthy, nutritious offerings that give a competitive advantage in current beverage market. The implementation of intelligent platforms enables companies and researchers to gather, store and analyze data in a more convenient way. The development of data collection methods contributed to the big data environment of TFABs, providing a fresh perspective that helps brewers to observe and improve the production steps. Among data analytical tools, Artificial Intelligence (AI) is considered to be one of the most promising methodological approaches for big data analytics and decision-making of automated production, and machine learning (ML) is an important method to fulfill the goal. This review describes the development trends and challenges of TFABs in big data era and summarize the application of AI-based methods in TFABs. Finally, we provide perspectives on the potential research directions of new frontiers in application of AI approaches in the supply chain of TFABs.
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AIM: Microbial communities exhibit different diversity and fluctuations in the ecological functions due to time and environmental migration. Despite a long history of research and a plethora of data, the factors determining the biodiversity and stability of ecosystems is still elusive. METHODS AND RESULTS: Here, the Chinese Xiaoqu fermentation system was used as a template to explore the mechanism in which the species specificity and strain in the initial phase affect the community structure and metabolites in the subsequent micro-ecosystem. The micro-ecosystem has been applied for hundreds of years, and the main metabolic function can be reproduced and traced. CONCLUSIONS: The result proved that Rhizopus spp. is a keystone microbe with a species/strain specificity affecting the trophic interaction niche and function of modules in the complex community through glucose. The fungal community was demonstrated to have a high sealing and stability, while the bacterial community was generally found to change the community structure, physiological function, and interaction relationship, producing strains with connector functions to adapt to fluctuations. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that the taxonomic level of key microbial strains can be changed to affect the evolution of coexistence and functional realisation of the community.
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Microbiota , Micobioma , Bactérias/genética , Biodiversidade , Ecossistema , Especificidade da EspécieRESUMO
Trans-4-hydroxy-L-pipecolic acid (trans-4-HyPip) is a hydroxylated product of L-pipecolic acid, which is widely used in the pharmaceutical and chemical industries. Here, a trans-4-HyPip biosynthesis module was designed and constructed in Escherichia coli by overexpressing lysine α-oxidase, Δ1-piperideine-2-carboxylase reductase, glucose dehydrogenase, lysine permease, catalase and L-pipecolic acid trans-4-hydroxylase for expanding the lysine catabolism pathway. A total of 4.89 g/L of trans-4-HyPip was generated in shake flasks from 8 g/L of L-pipecolic acid. By this approach, 14.86 g/L of trans-4-HyPip was produced from lysine after 48 h in a 5 L bioreactor. As far as we know, this is the first multi-enzyme cascade catalytic system for the production of trans-4-HyPip using E. coli from L-lysine. Therefore, it can be considered as a potential candidate for the industrial production of trans-4-HyPip in microorganisms.
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Proteínas de Escherichia coli , Escherichia coli , Proteínas da Membrana Bacteriana Externa/metabolismo , Catalase/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Glucose 1-Desidrogenase/metabolismo , Hidroxiácidos/metabolismo , Lisina/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Preparações Farmacêuticas/metabolismo , Ácidos PipecólicosRESUMO
The mud cellar creates a unique microenvironment for the fermentation of strong-flavor baijiu (SFB). Recent research and long-term practice have highlighted the key roles of microbes inhabiting pit mud in the formation of SFB's characteristic flavor. A positive correlation between the quality of SFB and cellar age was extracted from practice; however, the evolutionary patterns of pit mud microbiome and driving factors remain unclear. Here, based on the variation regularity analysis of microbial community structure and metabolites of samples from cellars of different ages (â¼30/100/300 years), we further investigated the effects of lactate and acetate (main microbial metabolites in fermented grains) on modulating the pit mud microbiome. Esters (50.3% to 64.5%) dominated the volatile compounds identified in pit mud, and contents of the four typical acids (lactate, hexanoate, acetate, and butyrate) increased with cellar age. Bacteria (9.5 to 10.4 log10 [lg] copies/g) and archaea (8.3 to 9.1 lg copies/g) mainly constituted pit mud microbiota, respectively dominated by Clostridia (39.7% to 81.2%) and Methanomicrobia (32.8% to 92.9%). An upward trend with cellar age characterized the relative and absolute abundance of the most predominant bacterial and archaeal genera, Caproiciproducens and Methanosarcina. Correlation analysis revealed significantly (P < 0.05) positive relationships between the two genera and major metabolites. Anaerobic fermentation with acetate and lactate as carbon sources enhanced the enrichment of Clostridia, and furthermore, the relative abundance of Caproiciproducens (40.9%) significantly increased after 15-day fed-batch fermentation with lactate compared with the initial pit mud (0.22%). This work presents a directional evolutionary pattern of pit mud microbial consortia and provides an alternative way to accelerate the enrichment of functional microbes. IMPORTANCE The solid-state anaerobic fermentation in a mud cellar is the most typical feature of strong-flavor baijiu (SFB). Metabolites produced by microbes inhabiting pit mud are crucial to create the unique flavor of SFB. Accordingly, craftspeople have always highlighted the importance of the pit mud microbiome and concluded by centuries of practice that the production rate of high-quality baijiu increases with cellar age. To deepen the understanding of the pit mud microbiome, we determined the microbial community and metabolites of different-aged pit mud, inferred the main functional groups, and explored the forces driving the microbial community evolution through metagenomic, metabolomic, and multivariate statistical analyses. The results showed that the microbial consortia of pit mud presented a regular and directional evolutionary pattern under the impact of continuous batch-to-batch brewing activities. This work provides insight into the key roles of the pit mud microbiome in SFB production and supports the production optimization of high-quality pit mud.
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Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Argila/microbiologia , Aromatizantes/metabolismo , Microbiota , Vinho/análise , Archaea/classificação , Archaea/genética , Archaea/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , China , Fermentação , Aromatizantes/análise , Armazenamento de Alimentos/instrumentação , Vinho/microbiologiaRESUMO
A Gram-stain-negative, coccus-shaped, obligately anaerobic, non-motile and non-spore-forming bacterium, designated strain JN500902T, was isolated from the mud in a fermentation cellar used continuously over 30 years for Chinese strong-flavour baijiu production. Colonies were white, circular, convex and smooth-edged. Growth was observed at 20-40 °C (optimum, 37 °C), at pH 5.0-10 (optimum, pH 7.5), with 0-2â% (w/v) NaCl and with 0-4â% (v/v) ethanol. The Biolog assay demonstrated positive reactions of strain JN500902T in the metabolism of l-fucose and pyruvate. The predominant cellular fatty acids (>10â%) consisted of C16â:â0 and C14â:â0. The major end metabolites of strain JN500902T were acetic acid and ethanol when incubated anaerobically in liquid reinforced clostridial medium. Acetate was the major organic acid end product. The complete genome size of strain JN500902T was 3â420â321 bp with 3327 identified genes. The G+C content was 43.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain JN500902T with the family Lachnospiraceae, having low sequence similarity (92.8â%) to the nearest type strain, Syntrophococcus sucromutans DSM 3224T and forming a clearly distinct branch. Core genome phylogenetic analysis of the isolate and 134 strains belonging to the family Lachnospiraceae also revealed that strain JN500902T was well-separated from other genera of this family as a monophyletic clade. The average nucleotide identity and amino acid identity values between strain JN500902T and 134 Lachnospiraceae strains were less than 74 and 65â%, respectively. Considering its polyphasic characteristics, strain JN500902T represents a novel genus and species within the family Lachnospiraceae, for which the name Novisyntrophococcus fermenticellae gen. nov., sp. nov. is proposed. The type strain is JN500902T (=CICC 24502T=JCM 33939T).
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Clostridiales/classificação , Fermentação , Filogenia , Microbiologia do Solo , Anaerobiose , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Clostridiales/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Directional stress is an effective measure to change the community structure and improve the bioactivity of pit mud (PM). In this study, the addition of fortified Daqu to artificial PM (APM) was intended to disturb the microbial community and further affect metabolites. To evaluate the effect of fortified Daqu on culturing APM, the microbial communities of APM with or without the addition of fortified Daqu were investigated by fluorescence in situ hybridization and Illumina MiSeq. The results indicated that microbes (Clostridium sp., Clostridium kluyveri, hydrogenotrophic methanogens, and acetotrophic methanogens) related to the production of key aroma compounds increased notably when fortified Daqu was added. In particular, the hydrogenotrophic and acetotrophic methanogens increased by 6.19- and 4.63-fold after 30 days of culture. Subsequently, metabolites (organic acids, volatile compounds) were also analyzed by HPLC (high-performance liquid chromatography) and HS-SPME-GC-MS (headspace solid phase microextraction - gas chromatography - mass spectrometry). The results showed that the content of butyric acid and hexanoic acid was significantly higher when fortified Daqu was added to APM. In addition, the proportion of esters and phenols was also higher than in APM without fortified Daqu. A survey of the microbial compositions of APMs with or without added fortified Daqu indicated that the microbial community evolves into a functional community favoring liquor brewing. We have developed a novel process by disturbing the community diversity.
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Bebidas Alcoólicas/análise , Bebidas Alcoólicas/microbiologia , Archaea/classificação , Bactérias/classificação , Fungos/classificação , Microbiota , Archaea/genética , Bactérias/genética , Biodiversidade , China , Argila/microbiologia , DNA Bacteriano/genética , Fermentação , Aromatizantes/análise , Microbiologia de Alimentos , Fungos/genética , Cromatografia Gasosa-Espectrometria de Massas , Sequenciamento de Nucleotídeos em Larga Escala , Hibridização in Situ Fluorescente , RNA Ribossômico 16S/genética , Microextração em Fase Sólida , Fatores de TempoRESUMO
The location of a sensory cortex for temperature perception remains a topic of substantial debate. Both the parietal-opercular (SII) and posterior insula have been consistently implicated in thermosensory processing, but neither region has yet been identified as the locus of fine temperature discrimination. Using a perceptual learning paradigm in male and female humans, we show improvement in discrimination accuracy for subdegree changes in both warmth and cool detection over 5 d of repetitive training. We found that increases in discriminative accuracy were specific to the temperature (cold or warm) being trained. Using structural imaging to look for plastic changes associated with perceptual learning, we identified symmetrical increases in gray matter volume in the SII cortex. Furthermore, we observed distinct, adjacent regions for cold and warm discrimination, with cold discrimination having a more anterior locus than warm. The results suggest that thermosensory discrimination is supported by functionally and anatomically distinct temperature-specific modules in the SII cortex.SIGNIFICANCE STATEMENT We provide behavioral and neuroanatomical evidence that perceptual learning is possible within the temperature system. We show that structural plasticity localizes to parietal-opercular (SII), and not posterior insula, providing the best evidence to date resolving a longstanding debate about the location of putative "temperature cortex." Furthermore, we show that cold and warm pathways are behaviorally and anatomically dissociable, suggesting that the temperature system has distinct temperature-dependent processing modules.
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Aprendizagem por Discriminação , Lobo Frontal/fisiologia , Substância Cinzenta/diagnóstico por imagem , Lobo Parietal/fisiologia , Sensação Térmica , Adolescente , Adulto , Feminino , Lobo Frontal/diagnóstico por imagem , Substância Cinzenta/fisiologia , Temperatura Alta , Humanos , Masculino , Lobo Parietal/diagnóstico por imagemRESUMO
Wheat Qu plays the role of saccharification fermentation, providing microorganisms and flavor in the fermentation of huangjiu, and the use of functional microorganisms to fortify wheat Qu is becoming increasingly popular. Yet, the mechanisms promoting microbial successions of wheat Qu remain unclear. In this study, we first correlated microbial community succession with physicochemical factors (moisture, temperature, acidity, glucoamylase and amylase) in inoculated raw wheat Qu (IRWQ) with Saccharopolyspora rosea. The Mantel test was performed to investigate the significance and found that temperature (r = 0.759, P = 0.001), moisture (r = 0.732, P = 0.006), and acidity (r = 0.712, P = 0.017) correlated significantly with the bacterial community in phase 1 (0-40 h). Meanwhile, temperature correlated significantly with the fungal community in phases 1 and 2 (40-120 h). To confirm the effect of temperature on microbial communities, the artificial reduction of bio-heat (37°C) in IRWQ also reduced the relative abundance of heat-resistant microorganisms including Bacillus and Saccharopolyspora. A higher abundance of Saccharopolyspora (87%) in IRWQ was observed following biofortified inoculation of S. rosea, in which glucoamylase activity increased by 40% compared to non-inoculated raw wheat Qu (NIRWQ) (1086 U/g vs 776 U/g). Finally, the IRWQ was employed to mechanized huangjiu fermentation and it was found to reduce the bitter amino acid and higher alcohol content by 27% and 8%, respectively, improving the drinking comfort and quality of huangjiu.
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Bacillus , Microbiota , Glucana 1,4-alfa-Glucosidase/metabolismo , Bactérias/metabolismo , Bacillus/genética , Bacillus/metabolismo , Fermentação , ChinaRESUMO
Pit mud (PM) is fermenting agents in the strong-flavor baijiu (SFB) production. In this paper, the discrepancies in fermentation parameters, microbial community succession patterns and metabolic phenotypes were compared in multidimensional PMs. The results showed that pyruvic acid, succinic acid, S-Acetyldihydrolipoamide-E, glycerol and glyceric acid were the key metabolites responsible for the metabolic differences between the 2-, 30-,100- and 300-year multidimensional PMs, while the butanoic acid, heptyl, heptanoic acid, heptanoic acid ethyl ester, hexanoic acid and octanoic acid were the key differential flavor compounds in the 2-, 30-,100- and 300-year multidimensional PMs. Concurrently, the diversity and abundance of microbial community also exhibited significant differences between the new and old multidimensional PMs, the assembly pattern of bacterial communities changed from deterministic to stochasticity from lower (bottom of the pit and under the huangshui fluid) to upper PM (up the huangshui fluid and top of the pit). Key microorganisms related to the succession process of the lower PM were Clostridium, Methanobacterium, Petrimonas, Lactobacillus, Methanobrevibacter, Bellilinea, Longilinea, Bacillus. In contrast, the upper PM were Caproicibacter, Longilinea, Lactobacillus, Proteinphilum, Methanobrevibacter, Methanobacterium, Methanobacteriaceae, Petrimonas, Bellilinea and Atopobium. Redundancy analysis (RDA) indicated that the key environmental factors regulating the succession of microbial in upper PM were lactic acid, moisture, pH and available phosphorus. In contrast, the lower was lactic acid, acetic acid and ammonia N. Based on these results, heterogeneous mechanisms between new and old multidimensional PMs were explored, providing a theoretical support for improving the quality of new PM.
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Fermentação , Fenótipo , Bactérias/metabolismo , Bactérias/classificação , Microbiota , Aromatizantes/metabolismo , Microbiologia de Alimentos , PaladarRESUMO
Extrusion has been proven to be a novel approach for modifying the physicochemical characteristic of Baijiu vinasses (BV) to extract polysaccharides, contributing to the sustainable development of brewing industry. However, the comparison of the bioactivity and bioavailability of extruded (EX) and unextruded (UE) BV polysaccharides was unclear, which impended the determination of the efficacy of extrusion in BV resourcing. In this study, in vitro digestion and fecal fermentation experiments were conducted to investigate the bioavailability, and the results showed that EX exhibited less variation in the monosaccharide composition and molecular weight, while exhibiting a stronger antioxidant capacity compared to UE. Moreover, during fermentation EX increased the abundance of Parasutterella and Lachnospiraceae, while UE promoted the proliferation of Bacteroides, Faecalibacterium, and Dialister, resulting in variation in short-chain fatty acids. These findings indicate that extrusion can enhance the capacity of antioxidants and bioavailability of BV polysaccharides.
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Antioxidantes , Disponibilidade Biológica , Fezes , Fermentação , Polissacarídeos , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Antioxidantes/química , Polissacarídeos/química , Fezes/química , Fezes/microbiologia , Digestão , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Monossacarídeos , HumanosRESUMO
Mulberry perishes easily due to its high water content and thin skin. It is important to extend the shelf life of mulberry by proper processing methods. In the present study, the influence of three drying techniques, including hot air drying (HAD), vacuum drying (VD), and vacuum freeze-drying (VFD) on the quality maintenance of mulberry was comprehensively evaluated. Bioactive compounds, antioxidant activity, and the sensory and volatile flavor compounds of mulberry have been researched. The results showed that VFD treatment maintained the highest anthocyanins (6.99 mg/g), total flavones (3.18 mg/g), and soluble sugars (2.94 mg/g), and exhibited the best DPPH· (81.2%) and ABTS+· (79.9%) scavenging ability. Mulberry also presented the lowest hardness and the greatest brittleness after VFD. Additionally, VFD maintained the optimal color and presented the best sensory attributes. Furthermore, 30, 20, and 32 kinds of volatile flavor compounds were detected in HAD, VD, and VFD, respectively, among which aldehydes, esters, and ketones were the most abundant compounds. This study indicated the potential application value of VFD for the drying of fruit and vegetable foodstuffs.