Select

Analysis on Physiological Characteristics and Transcriptome of Saccharomyces cerevisiae under Carvacrol Stress

Li-Yuan NIU Zi-Hao WU Yan-Hong Bai Zhi-Jian ZHANG

FOOD SCIENCE 0, (): 0-0.

Abstract （18）

PDF（pc）（1008KB）（8）

Save

This study selected Saccharomyces cerevisiae, the common spoilage fungus in fruit and vegetable products, as the target microorganism, and investigated the physiological characteristics and transcriptome of S. cerevisiae under carvacrol stress. The minimum inhibitory concentration of carvacrol on S. cerevisiae was 160 g/mL. With the increase of treatment temperature (20~40℃), the inhibitory effect of carvacrol (160 μg/mL) on yeast growth gradually increased; environmental pH (3~4.5) had no significant influence on the inhibitory effect of carvacrol; however, the addition of fructose (20~80 g/L) significantly reduced the antifungal activity. The carvacrol stress induced the damage on the structure of cell envelope, the increase in the plasma membrane permeability, the membrane depolarization, and even the leakage of intracellular substances of S. cerevisiae. Carvacrol also led to the increase of intracellular Ca2+ level, the mitochondrial depolarization, and the decrease of intracellular ATP content. The transcriptomic analysis found that carvacrol stress inhibited the biosynthesis of mitochondrial respiratory chain complex, ATP synthase and mitochondrial ribosome (MR) proteins, which could block the electron transport in the respiratory chain and interfere with life activities related to MR.

Reference | Related Articles | Metrics

Select

Characterization of Hydrolysis of Bone Collagen from Different Sources of Livestock and Poultry by Prolyl Endopeptidase

Chunhui ZHANG

FOOD SCIENCE 0, (): 0-0.

Abstract （19）

PDF（pc）（1449KB）（6）

Save

To investigate the potential of prolyl endopeptidase (PEP) in the enzymatic preparation of bone collagen peptides, bovine bone collagen (BBC), porcine bone collagen (PBC) and chicken bone collagen (CBC) were used as raw materials. The sequence characteristics of the three different collagen sources were compared and analyzed to predict the potential enzymatic sites and theoretical hydrolysis degrees of the different collagens based on the PEP substrate specificity analysis. Three different collagen sources were enzymatically treated with PEP at 55℃ and pH 8.0, and the enzymatic effects of PEP on different collagen were analyzed by scanning electron microscopy, apparent turbidity changes, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and confirmed by hydrolysis degree and molecular weight changes. Infrared spectroscopy, X-ray diffraction and circular dichroism were used to explore the structural changes of collagen during enzymatic digestion. The results showed that PEP had significant hydrolysis effect on three different sources of collagen. The hydrolysis degree of pig collagen was the highest at 51.35%, followed by bovine collagen at 22.81% and chicken collagen at 29.81%. The molecular weight of the three collagen proteinase hydrolysates mostly distributed below 500 Da. Spectroscopic analysis showed that PEP destroyed the triple helix structure of collagen, and then degraded collagen to achieve the effect of collagen peptide preparation. Conclusion: Prolyl endopeptidase can efficiently enzymolize collagen to prepare small molecule protein peptide, which provides the basis for the enzymatic preparation of functional collagen peptide.

Reference | Related Articles | Metrics

Select

Effects of intensive fermentation of Monascus on flavor substances and Microflora structure of soybean paste

四强蒋 Zhiyi Fan 李婷 Heng LI qisheng zhang

FOOD SCIENCE 0, (): 0-0.

Abstract （74）

PDF（pc）（701KB）（47）

Save

Soybean paste intensive fermented with mixed koji of Aspergillus oryzae (Pi-niang M003) and Monascus purpureus (PM001) was analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry, principal component analysis system to compare the volatile flavor components in different mixed fermented soybean paste, and Illumina Miseq sequencing technology was used to analyze the microbial structure in different soybean paste fermentation process, and the correlation between the main microorganisms and the key flavor substances was analyzed by correlation analysis. The results showed that the intensive fermentation of Monascus has a significant effect on the flavor substances and microbial structure of soybean paste during fermentation; Spearman correlation analysis of dominant genera and flavor substance components found that many flavor substances in soybean paste were significantly positively correlated with dominant genera, and Monascus intensive fermented soybean paste had more abundant flavor substance types and contents, among which Monascus intensive fermented soybean paste C had better flavor quality. The results indicate that Monascus intensive fermented soybean paste can significantly improve the flavor quality of soybean paste, and provide data reference for the improvement of soybean paste flavor quality.

Reference | Related Articles | Metrics

Select

Establishment and application of real-time fluorescence quantitative PCR detection method for Lactobacillus kefiranofaciens subsp. kefiranofaciens

LV Houjiao Longgang Jia

FOOD SCIENCE 0, (): 0-0.

Abstract （15）

PDF（pc）（918KB）（7）

Save

Abstract: Lactobacillus kefiranofaciens subsp. kefiranofaciens is a new food raw material approved in China in 2021, which has broad application prospects in the fields of food, medicine and cosmetics. In order to be able to rapidly and specifically detect the subspecies of Lactobacillus kefiranofaciens subsp. kefiranofaciens, a specific real-time PCR detection method was established. Specific primers were designed to screen specific primers according to the 16S rDNA sequence and whole genome sequence of the ZW3 subspecies of Lactobacillus kefiranofaciens subsp. kefiranofaciens of the model strain, and a real-time PCR method was established by SYBR Green I fluorescent dye, and the specificity, sensitivity, repeatability and mixed system of the method were detected. The results showed that the method established in this study had strong specificity, high sensitivity and good repeatability, and the standard curve of real-time PCR is established, and its linear correlation coefficient R2 is 0.965, which had a good linear relationship. Moreover, this method can be specifically detected in the subspecies and mixed systems of Lactobacillus kefiranofaciens subsp. kefiranofaciens. In summary, the real-time PCR method established in this study could quickly and accurately detect the subspecies of Lactobacillus kefiranofaciens subsp. kefiranofaciens, which provided a new method for the specific qualitative and quantitative detection of Lactobacillus kefiranofaciens subsp. kefiranofaciens.

Related Articles | Metrics

Select

Study of microbial community structure and correlation with metabolites in traditional fermented yak dairy

Lynn Loeng Hong-Na LIU

FOOD SCIENCE 0, (): 0-0.

Abstract （91）

PDF（pc）（1700KB）（36）

Save

Abstract: To investigate the microbial diversity and the relevance of their metabolites in traditional yak fermented dairy products featured, the present study analyzed the microbial diversity and metabolite profiles of three traditional yak dairy products, ghee, Qula, and yak yogurt, by using high-throughput sequencing and GC-TOF-MS, respectively. Results showed that the microbial communities of the three dairy products differed significantly at the genus level, with Lactobacillus being the superior bacterial genus in yogurt and Qula, and Lactococcus being leading in ghee; Geotrichum and yeasts were found in all fungal genera. In particular, a high abundance of Pichi was detected in yak yogurt and Qula, and unique Kluyveromyce was also present in yogurt, whereas the fungal genus composition varied considerably within the ghee. The results could provide a basis for labeling the dominant microflora of traditional dairy products. Metabolomics combined with multivariate statistical analysis identified a total of 51 differential metabolites. The characteristic metabolites of ghee were mostly lipids and lipid-like molecules; Qula was similar to yogurt in that the characteristic metabolites were organic acids and derivatives, in addition to lipid and lipid-like molecules. A total of 12 metabolic pathways involved in the regulation of flavor and quality of dairy products. Correlation analysis showed that Lactococcus and Geotrichum were negatively correlated with the metabolites screened, and Lactobacillus and Kluyveromyce were positively correlated with most of the metabolites screened. Differences in microbial structure could lead to quite different metabolites and nutrients in fermented yak dairy products, and the study provides a theoretical basis for better quality control of fermented foods.

Reference | Related Articles | Metrics

Select

Characterization of Prolyl Endopeptidase-Hydrolyzed Bone Collagen from Different Species of Livestock and Poultry

ZHOU Jiaojiao, GUO Yujie, QI Liwei, ZHANG Hongru, LI Juan, ZHANG Chunhui

FOOD SCIENCE 2024, 45 (9): 66-74. DOI: 10.7506/spkx1002-6630-20230624-179

Abstract （3）

HTML （0）

PDF（pc）（8592KB）（0）

Save

In order to investigate the application potential of prolyl endopeptidase (PEP) in the enzymatic preparation of bone collagen peptides, the amino acid sequence characteristics of bovine bone collagen (BBC), porcine bone collagen (PBC) and chicken bone collagen (CBC) were comparatively analyzed, and their potential enzymatic cleavage sites and theoretical hydrolysis degrees were predicted. Collagen hydrolyzed by PEP at 55 ℃ and pH 8.0 was characterized by hydrolysis degree, molecular mass distributionand scanning electron microscopy (SEM). Infrared spectroscopy, X-ray diffraction (XRD) and circular dichroism (CD) spectroscopy were used to explore the structural changes of collagen during enzymatic digestion. The results showed that PEP could hydrolyze the three collagens. The hydrolysis degree of PBC was the highest (51.35%), followed by those of BBC (22.81%) and CBC (29.81%). The molecular masses of the three collagen hydrolysates were mostly distributed below 500 Da. Spectroscopic analysis showed that PEP destroyed the triple helix structure of collagen, and then degraded it. Therefore, PEP can efficiently enzymatically hydrolyze collagen into small molecule peptides, which provides a basis for the enzymatic preparation of functional collagen-derived peptides.

Related Articles | Metrics

Select

Physiological Characteristics and Transcriptomic Analysis of Saccharomyces cerevisiae under Carvacrol Stress

NIU Liyuan, SUN Xiaocheng, LIU Jingfei, WU Zihao, BAI Yanhong, ZHANG Zhijian

FOOD SCIENCE 2024, 45 (9): 75-83. DOI: 10.7506/spkx1002-6630-20230621-170

Abstract （6）

HTML （0）

PDF（pc）（5829KB）（2）

Save

This study investigated the effect of carvacrol stress on the physiological characteristics and transcriptome of Saccharomyces cerevisiae, a common spoilage yeast in fruit and vegetable products. The results showed that the minimum inhibitory concentration (MIC) of carvacrol on S. cerevisiae was 160 mg/mL. With the increase in temperature (20–40 ℃), the inhibitory effect of carvacrol (160 mg/mL) on yeast growth gradually increased. Environmental pH (3–4.5) had no significant impact on the inhibitory effect of carvacrol. However, the addition of fructose (20–80 g/L) significantly reduced the antifungal activity. Carvacrol treatment damaged the structure of the cell envelope of S. cerevisiae, increased the plasma membrane permeability and caused plasma membrane depolarization, resulting in leakage of intracellular substances, a decrease in mitochondrial membrane potential, an imbalance in intracellular Ca2＋ homeostasis, and a decrease in intracellular ATP content. The transcriptomic analysis revealed that carvacrol stress inhibited the biosynthesis of mitochondrial respiratory chain complexes, ATP synthase and mitochondrial ribosome (MR) proteins, which could block electron transport along the respiratory chain and interfere with life activities related to MR.

Related Articles | Metrics

Select

Microbial Community Structure and Correlation with Metabolites in Traditional Fermented Yak Milk Products

LIANG Xiaolin, ZHANG Zhechuan, WANG Yuhao, DING Bo, LIU Hongna

FOOD SCIENCE 2024, 45 (9): 84-92. DOI: 10.7506/spkx1002-6630-20230918-165

Abstract （2）

HTML （0）

PDF（pc）（5562KB）（1）

Save

To investigate the microbial diversity and the correlation with metabolites in traditional fermented yak milk products, the study used high-throughput sequencing and gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) to analyze the microbial diversity and metabolite profiles of yak ghee, Qula, and yogurt. Results showed that the microbial communities of the three dairy products differed significantly at the genus level. The dominant bacterial genus in yak yogurt and Qula was Lactobacillus, while Lactococcus was dominant in ghee. The fungi Geotrichum and yeast were found in all samples. In particular, a high abundance of Pichi was detected in yak yogurt and Qula, and Kluyveromyce was exclusively present in yogurt, whereas the fungal genus composition varied considerably among ghee samples. Using metabolomics combined with multivariate statistical analysis, a total of 51 differential metabolites were identified. The characteristic metabolites of ghee were lipids and lipid-like molecules, and the characteristic metabolites of Qula and yogurt were similar, including organic acids and their derivatives as well as lipid and lipid-like molecules. A total of 12 metabolic pathways were found to be involved in the regulation of the flavor and quality of fermented yak milk products. Correlation analysis showed that Lactococcus and Geotrichum were negatively correlated with selected metabolites, while Lactobacillus and Kluyveromyce were positively correlated with most of the metabolites. Differences in the microbial community structure could lead to differences in the metabolite profile of fermented yak milk products. The results from this study provide a theoretical basis for better regulating the quality of fermented yak milk products.

Related Articles | Metrics

Select

Effect of Co-fermentation with Monascus and Aspergillus oryzae on Flavor Substances and Microfloral Structure of Soybean Paste

JIANG Siqiang, CHEN Gong, LI Xiongbo, WANG Zeliang, FAN Zhiyi, LI Ting, LI Heng, ZHANG Qisheng, DENG Weiqin

FOOD SCIENCE 2024, 45 (9): 93-101. DOI: 10.7506/spkx1002-6630-20230531-288

Abstract （4）

HTML （0）

PDF（pc）（4813KB）（0）

Save

In order to explore the effect of co-fermentation with Monascus and Aspergillus oryzae on the quality of soybean paste, the volatile flavor components in soybean pastes produced using pure and mixed cultures of A. oryzae (Piniang M003) and Monascus (PM001) were determined by headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and comparatively analyzed by principal component analysis (PCA), and Illumina MiSeq sequencing technology was used to analyze the changes in the microbial community structure during the mixed culture fermentation process. Meanwhile, the correlation between the major microorganisms and the major flavor substances was analyzed. The results showed that the composition and content of flavor substances and the composition and relative abundance of microbial communities in the soybean paste produced by co-fermentation were significantly better than those in the soybean paste fermented with A. oryzae monoculture. The major flavor substances in soybean paste were significantly positively correlated with dominant genera such as Aspergillus, Bacillus, Monascus and Leuconostoc. The flavor quality of the soybean paste produced with a mixed culture of A. oryzae and Monascus in a ratio of 3:1 (m/m) was best. The results of the study showed that the mixed culture fermentation with Monascus and A. oryzae could significantly improve the flavor quality of soybean paste, which will be informative for the improvement of the flavor quality of soybean paste.

Related Articles | Metrics

Select

Establishment and Application of Real-time PCR Detection Method for Lactobacillus kefiranofaciens subsp. kefiranofaciens

Lü Houjiao, LI Xinyuan, BAI Xiaojia, JIA Longgang, GENG Weitao, WANG Yanping

FOOD SCIENCE 2024, 45 (9): 102-108. DOI: 10.7506/spkx1002-6630-20230710-109

Abstract （4）

HTML （0）

PDF（pc）（4712KB）（0）

Save

This study developed a real-time polymerase chain reaction (real-time PCR) method for the detection of Lactobacillus kefiranofaciens subsp. kefiranofaciens. Based on the 16S rDNA gene sequence and whole genome sequence of the type strain of L. kefiranofaciens subsp. kefiranofaciens ZW3, specific primers were designed and screened. The fluorescent dye SYBR Green I was used in the real-time PCR method. Its specificity, sensitivity and repeatability were evaluated, and this method was applied to detect several strains of this species and its mixtures with other lactic acid bacteria. The results showed that the proposed method was highly specific, sensitive and repeatable. The standard curve was linear with a determination coefficient (R2) of 0.965. Moreover, this method could specifically detect L. kefiranofaciens subsp. kefiranofaciens from its mixture with other lactic acid bacteria. In summary, the real-time PCR method could quickly and accurately detect L. kefiranofaciens subsp. kefiranofaciens, providing a new method for the specific qualitative and quantitative detection of L. kefiranofaciens subsp. kefiranofaciens.

Related Articles | Metrics

Select

Screening, Identification, and Genome Annotation of Esterase-producing Lactococcus garvieae

cong chen Zou Wei

FOOD SCIENCE 0, (): 0-0.

Abstract （14）

PDF（pc）（3369KB）（9）

Save

Esterases are mainly composed of lipases, ester synthases, and phosphatase. Lipases can hydrolyze large molecules of fatty acids into glycerol and long-chain fatty acids. Ester synthases can synthesize medium-chain fatty acid esters from medium-chain fatty acids. Phosphatase hydrolyze phosphate ester into inorganic phosphate and corresponding alcohols or acids. In this study, a strain S5-4 was isolated from the daqu of Nongxiangxing Baijiu, and identified as Lactococcus garvieae. After preliminary screening and re-screening. it would produce the largest clear zone that the diameter-to-diameter (D/d) ratio of this strain reached 2.27±0.02. Its morphology and physiological characteristics were identified, and the enzymatic activity of its esterase was measured to reach 15.74 U/mL. After 15 days of anaerobic fermentation at 35°C, the strain was able to synthesize ethyl acetate with a concentration of 0.3450±0.16 g/L and ethyl lactate with a concentration of 0.2983±0.23 g/L. The genome sequencing and annotation results of strain S5-4 showed that its genome size is 2,191,113bp with a GC content of 37.99%. A total of 1486 genes, 4 rRNA genes, 69 tRNA genes, and 34 ncRNA genes were predicted. The genome annotation also revealed the presence of 11 types of esterase genes in S5-4, including phosphatases (5 intracellular and 2 membrane), acyl-CoA dehydrogenase (intracellular), triacylglycerol lipase (extracellular), carboxylase (extracellular), and hemicellulose esterase (intracellular). Based on functional genome annotation, metabolic pathways for ethyl acetate and ethyl lactate production using starch and lactose as carbon sources were constructed, which were consistent with experimental results. According to the esterase characteristics of the strain, it can be used as a biocatalyst for producing esterification liquids in baijiu production or added as an enhancer to daqu to enhance its aromatic effect.

Reference | Related Articles | Metrics

Select

Isolation, identification and probiotic characterization of lactic acid bacteria from forest musk deer

FOOD SCIENCE 0, (): 0-0.

Abstract （13）

PDF（pc）（762KB）（7）

Save

To isolate and screen lactic acid bacteria with great probiotic performance from healthy forest musk deer feces, which have good potential to improve the health status of forest musk deer, and to evaluate the in vitro probiotic characteristics of isolates. Twelve isolates were obtained and identified by cell morphology and bacterial 16S rDNA sequencing. Their survival in low pH and bile salts, antagonistic activities against five target pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa PAO1, Salmonella enteritidis ATCC 13076 and Arcanobacterium pyogenes LSN3), auto-aggregation and hydrophobicity, antibiotic susceptibility and resistance genotype, growth curve were evaluated. Five Lactiplantibacillus plantarum isolates and Pediococcus acidilactici isolate showed prominent probiotic potential than others. Specifically, these isolates survived at pH4, or in 0.5% bile salt (survival rate was more than 88.5.% and 87%); inhibited the target pathogens (inhibition zone was 17.20～20.19 mm) and Arcanobacterium pyogenes LSN3 (inhibition zone was 14.23～15.53 mm) ; possessed considerable auto-aggregation (53.1%~56.2%) and hydrophobicity (52.9%～?56.0%); resisted to streptomycin, ciprofloxacin and vancomycin, carried the vanX gene. They have the characteristics of rapid growth (the OD600 reached 9.0 and 7.1, respectively.). Our findings demonstrated that these six isolates could be?preliminarily determined as probiotic candidates, they might be excellent candidates for subsequent development of forest musk deer probiotics.

Reference | Related Articles | Metrics

Select

Isolation and Screening of Lactic Acid Bacteria from the Gut of Forest Musk Deer for Probiotic Properties

ZI Jing, WANG Yan, LI Liangliang, ZHANG Kun, WAN Yi

FOOD SCIENCE 2024, 45 (8): 79-86. DOI: 10.7506/spkx1002-6630-20230714-171

Abstract （4）

HTML （0）

PDF（pc）（2842KB）（2）

Save

This study aimed to isolate and select potential probiotic strains from the feces of healthy forest musk deer and to evaluate their in vitro probiotic characteristics. Twelve isolates were obtained and identified by cell morphology and bacterial 16S rDNA sequencing. Their survival under low pH and bile salt conditions, antagonistic activities against five pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa PAO1, Salmonella enteritidis ATCC 13076 and Arcanobacterium pyogenes LSN3), auto-aggregation characteristics, hydrophobicity, antibiotic susceptibility and antibiotic resistance genotypes, and growth curves were evaluated. The results showed that five Lactiplantibacillus plantarum isolates and one Pediococcus acidilactici isolate survived at pH 4, or in 0.5% bile salt with survival rates of more than 88.5% and 87%, respectively. All of them inhibited the five pathogens with diameters of inhibition zones of 17.20-20.19 mm for E. coli ATCC 25922, S. aureus ATCC 25923, P. aeruginosa PAO1 and S. enteritidis ATCC 13076 and of 14.23-15.53 mm for A. pyogenes LSN3. They had similar auto-aggregation capacity (53.1%–56.2%) and surface hydrophobicity (52.9%–56.0%) to L. paracasei L22. They were resistant to streptomycin, ciprofloxacin and vancomycin, carried the vanX gene and rapidly grew; the optical density at 600 nm (OD600) reached 9.0 and 7.1 for L. plantarum and P. acidilactici from the gut of forest musk deer after 24 h incubation, respectively. Our findings demonstrated that these six isolates can be used as sources for the development of probiotic preparations intended for forest musk deer.

Related Articles | Metrics

Select

Screening, Identification and Genome Annotation of Esterase-Producing Lactococcus garvieae

CHEN Cong, ZOU Wei, TANG Xiujuan, CHEN Xiaosong, WU Chengze

FOOD SCIENCE 2024, 45 (8): 87-95. DOI: 10.7506/spkx1002-6630-20230714-161

Abstract （3）

HTML （1）

PDF（pc）（5778KB）（2）

Save

In this study, a strain, named S5-4, with high esterase activity was obtained from Nongxiangxing Daqu by primary and secondary screening, and subjected to whole genome sequencing, esterase annotation and metabolic pathway analysis. The strain exhibited a maximal ratio of transparent zone diameter to colony diameter (D/d) of 2.27 ± 0.02, and it was identified as Lactococcus garvieae. Its morphological, physiological, and biochemical characteristics were determined, and its esterase activity was measured to be 15.74 U/mL. This strain produced (0.345 0 ± 0.160 0) g/L of ethyl acetate and (0.298 3 ± 0.230 0) g/L of ethyl lactate after anaerobic fermentation at 35 ℃ for 15 days. The genome size of S5-4 was determined to be 2 191 113 bp in length, with a GC content of 37.99%. A total of 1 486 genes, including 4 rRNA genes, 69 tRNA genes, and 34 ncRNA genes were predicted. In total, 11 esterase genes were annotated in the genome of S5-4 including phosphatases (five intracellular ones and two membrane ones), acyl-CoA dehydrogenase (intracellular), triacylglycerol lipase (extracellular), carboxylase (extracellular), and hemicellulose esterase (intracellular). Based on functional genomic annotation, the metabolic pathways to produce ethyl acetate and ethyl lactate from starch and galactose as carbon sources were constructed and found to be consistent with the experimental results. Given its ability to produce esterase, the strain could be used as a biocatalyst for esterification in baijiu fermentation or as a flavor enhancer in Daqu production.

Related Articles | Metrics

Select

Succession of Microbial Community Structure and Its Correlation Analysis with Physicalchemical Indicators in Fermented Grains during Nongxiangxing baijiu Fermentation

波曾静文 Huang Zhi-Guo

FOOD SCIENCE 0, (): 0-0.

Abstract （3）

Save

Abstract：The formation of Nongxiangxing Baijiu flavor is inseparable from the microbial metabolism which influences the physicochemical environment of the fermented grains. In order to clarify the succession law and potential function of microbial in the fermented grains of Nongxiangxing Baijiu. High-throughput sequencing was borrowed to reveal the succession of microbial community structure , and the relationship between microbial community structure and physicalchemical indicators was analyzed in different fermentation stages. PICRUSt analyse was used to predict the potential function of bacterial community in the fermented grains. The results showed that Firmicutes, Proteobacteria, Actinobacteriota, Ascomycota, and Basidiomycota were the dominant phylums in the fermented grains. The dominant microorganisms were Lactobacillus、Bacillus、Staphylococcus、Thermoactinomyces、Kazachstania、Wickerhamomyces、Penicillium、Candida、Aspergillus、Meyerozyma、Debaryomyces，Lactobacillus、Kazachstania and Wickerhamomyces being absolutely dominant. The correlation analysis between physicochemical indicators and microbial diversity showed that reducing sugar and starch have a significant positive correlation with 8 bacteria. Acidity and moisture have a significant negative correlation with 10 bacteria. Some fungi are significantly correlated with physicalchemical indicators.PICRUSt analysis showed that the relative abundance of functional enzymes at different fermentation stage was significantly different, and the dominant microbial in the fermented grains participate in glycolysis, acid metabolism and ethanol synthesis to form a complete metabolic chain, indicating that the succession of the microbial community of the fermented grains is the main reason for the differences in metabolism at different fermentation nodes. This study analyzes the succession law of microbial community structure in the fermented grains and their metabolism in the fermentation process, which provides a theoretical basis for the study of the metabolic mechanism of baijiu brewing microorganisms.

Reference | Related Articles | Metrics

Select

Effect of Saccharomyces cerevisiae on quality and flavor of fermented sausage

null

FOOD SCIENCE 0, (): 0-0.

Abstract （3）

Save

In order to improve the quality and flavor of fermented sausage, Saccharomyces cerevisiae Y-8 was inoculated to explore the effects of different proportions of S.cerevisiae Y-8 and Lactiplantibacillus plantarum Z43 on the physical and chemical properties, volatile flavor compounds and fatty acids of fermented sausage. The volatile flavor compounds and fatty acid were determined by Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) and Gas Chromatography-Mass Spectrometry (GC-MS), respectively. The results showed that the addition of S. cerevisiae Y-8 could promote the production of esters and alcohols, reduce acetic acid content, increase the final pH, enheance the proportion of oleic acid, and rapidly reduce the number of enterobacteria. The model was established using Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), 17 differential volatile flavor substances (VIP > 1) were identified, which could effectively distinguish the sausages fermented with different proportional combinations of S. cerevisiae Y-8 and L. plantarum Z43. The combination of L. plantarum Z43 and S. cerevisiae Y-8 in a ratio of 20:1(the inoculum of L. plantarum Z43 was 107CFU/g) had the highest comprehensive sensory evaluation, the highest chrominance value, and the hardness value were significantly higher than the other groups (P < 0.05), the contents of 3-hydroxy-2-butanone and isoamyl alcohol monomer were significantly higher than those in the other groups. Inoculation with S. cerevisiae Y-8 can give fermented sausage rich mellow and ester flavor, effectively eliminate sour taste, improve the quality and safety of fermented sausage, and provide useful reference for the application of S. cerevisiae in fermented meat products.

Reference | Related Articles | Metrics

Select

Influence mechanism of Saccharomyces cerevisiae on microbial community succession during Nongxiangxing Baijiu fermentation

Huibo Luo Chuan SONG Dan Huang Hui-Bo LUO

FOOD SCIENCE 0, (): 0-0.

Abstract （25）

PDF（pc）（1763KB）（7）

Save

Abstract: The changes of microbial niche and community assembly of fermented grains during Nongxiangxing Baijiu fermentation by Saccharomyces cerevisiae were analyzed to explore its influence mechanism on microbial succession of fermented grains. In this study, a strain of Saccharomyces cerevisiae screened from Nongxiangxing Baijiu was inoculated into fermented grains for fermentation experiment, and the microbial community structure of fermented grains in control group and experimental group was studied by high-throughput sequencing technology, and the niche changes of control group and experimental group were studied by statistical analysis method, and the assembly mechanism of microbial community was analyzed by zero model. The results showed that compared with the control group, the diversity and species composition of microbial communities in the experimental group decreased, the niche width of microbial communities in the experimental group decreased, and the relative content of specialized species groups increased. In the co-occurrence network, the relative abundance of specialized species in the main modules of the experimental group network increases, and the network complexity increases. The assembly of microbial communities in the control group and the experimental group is mainly dominated by random processes, but the importance of ecological drift and homogeneous diffusion in the experimental group is reduced, which makes the microbial community succession more certain. This study will further reveal the ecological function of Saccharomyces cerevisiae in the process of Nongxiangxing Baijiu fermentation, which has an important impact on Baijiu fermentation.

Reference | Related Articles | Metrics

Select

Identification and application of effectors promoting asexual sporulation of Antrodia cinnamomea in aqueous extract of Cinnamomum kanehirae Hay

Hua-Xiang LI

FOOD SCIENCE 0, (): 0-0.

Abstract （10）

PDF（pc）（702KB）（6）

Save

In order to determine the substance in aqueous extract of Cinnamomum kanehirae Hay (CWE) that promotes the asexual sporulation of Antrodia cinnamomea in submerged fermentation. Firstly, the CWE was isolated by alcohol precipitation and fractional extraction with different organic solvents, and the sporulation was used as the index to study the influence of different components on the sporulation of A. cinnamomea. It was showed that 30 μg/mL of chloroform extract of supernatant from alcohol precipitation of CWE (LFE) and 50 μg/mL of ethyl acetate extract (YZE) had a remarkable effect on promoting sporulation of A. cinnamomea, indicating that the effectors mainly existed in LFE and YZE; Subsequently, LC-MS/MS was used to analyze the components of different extracts of CWE, and combined with their effects on sporulation of A. cinnamomea, it was judged that the effector was probably erythritol; Finally, the commercial erythritol with purity of 98% was used to verify its effect on sporulation of A. cinnamomead. It was showed that erythritol did significantly promote the sporulation of A. cinnamomea, and the sporulation increased by 55.17% compared with Control at the optimal concentration of 1 μg/mL. Meanwhile, 1 μg/mL of erythritol can also significantly promote the growth and the synthesis of intracellular polysaccharides (IPS) for A. cinnamomea in submerged fermentation, and the biomass and yield of IPS were increased by 18.65% and 260.13%, respectively. However, erythritol has no significant effect on the synthesis of triterpenes. This study can greatly improve the industrial production efficiency and benefits of submerged fermentation for A. cinnamomea, and have great development value and good application prospects.

Reference | Related Articles | Metrics

Select

Identification of Water-Soluble Compounds from Cinnamomum kanehirae Hay Promoting the Asexual Sporulation of Antrodia cinnamomea and Optimization of Their Addition Levels in the Culture Medium

LI Huaxiang, DAI Jianing, WANG Juanjuan, LIU Boling, JI Dan, LUO Zhishan, LU Zhenming, YANG Zhenquan

FOOD SCIENCE 2024, 45 (7): 96-102. DOI: 10.7506/spkx1002-6630-20230728-317

Abstract （7）

HTML （0）

PDF（pc）（3561KB）（4）

Save

In order to determine compounds present in the aqueous extract of Cinnamomum kanehirae Hay (CWE) that promote the asexual sporulation of Antrodia cinnamomea in submerged fermentation. First, CWE was isolated by alcohol precipitation and fractional extraction with different organic solvents. The influence of the obtained fractions on the asexual sporulation of A. cinnamomea was investigated. It was showed that the chloroform (at 30 μg/mL) and ethyl acetate (at 50 μg/mL) extracts of the supernatant after ethanol precipitation of CWE presented remarkable promoting effects on the sporulation of A. cinnamomea, and the effect of LFE was significantly more pronounced than that of YZE, indicating that both LFE and YZE contained compounds that promote the sporulation of A. cinnamomea. Subsequently, liquid chromatography-mass spectrometry (LC-MS) was used to analyze the chemical components of the fractions obtained from CWE, and erythritol was considered as the major component that promotes the sporulation of A. cinnamomea. Finally, the effect of erythritol with a purity of 98% on the fermentation performance of A. cinnamomead was investigated. The result showed that erythritol did significantly promote the sporulation of A. cinnamomea and increased the spore production by 55.17% compared with the control group at the optimal concentration of 1.0 μg/mL. Meanwhile, 1.0 μg/mL erythritol significantly promoted the mycelial growth and synthesis of intracellular polysaccharides (IPS) of A. cinnamomea in submerged fermentation and increased the biomass and the yield of IPS by 18.65% and 260.13%, respectively. However, erythritol had no significant effect on the synthesis of triterpenes in A. cinnamomea.

Related Articles | Metrics

Select

Mechanism for the Influence of Saccharomyces cerevisiae on Microbial Community Succession during Nongxiangxing Baijiu Fermentation

WANG Shuanghui, MA Shiyuan, LI Zijian, SONG Chuan, DAI Hancong, SHAO Yan, HUANG Dan, LUO Huibo

FOOD SCIENCE 2024, 45 (7): 103-110. DOI: 10.7506/spkx1002-6630-20230803-024

Abstract （21）

HTML （5）

PDF（pc）（9064KB）（19）

Save

The changes in the microbial niche and community assembly of fermented grains for Nongxiangxing baijiu during fermentation by Saccharomyces cerevisiae were analyzed to explore the mechanism for the influence of inoculation with S. cerevisiae on the microbial succession of fermented grains. In this study, a strain of S. cerevisiae isolated from fermented grains for Nongxiangxing baijiu was inoculated into distilled grains for fermentation experiments, and the microbial community structures of fermented grains with (experimental) and without (control) inoculation with S. cerevisiae were studied by high-throughput sequencing technology, and the niche changes of the control and experimental groups were studied by statistical analysis, and the mechanism of microbial community assembly was analyzed by the zero model. The results showed that compared with the control group, the diversity, species composition and niche width of microbial communities in the experimental group decreased, and the relative content of specialized species groups increased. In the co-occurrence network, the relative abundance of specialized species in the major modules of the experimental group increased, and the network complexity increased. The assembly of microbial communities in the two groups was mainly dominated by random processes, while ecological drift and homogeneous diffusion in the experimental group were less important for community construction, which made the microbial community succession more certain. This study revealed the ecological function of S. cerevisiae in Nongxiangxing baijiu fermentation, which could have an important impact on baijiu fermentation.

Related Articles | Metrics

Content of Bioengineering in our journal