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1.
Sheng Wu Gong Cheng Xue Bao ; 36(6): 1190-1197, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597068

RESUMO

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.


Assuntos
Bebidas Alcoólicas , Clostridium , Microbiologia de Alimentos , Bebidas Alcoólicas/microbiologia , Bactérias/classificação , Bactérias/metabolismo , Clostridium/fisiologia , Ácidos Graxos Voláteis/metabolismo , Fermentação
2.
Int J Syst Evol Microbiol ; 70(5): 3406-3412, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375947

RESUMO

A Gram-stain-positive, strictly aerobic and rod-shaped bacterium, designated as 3 H-10T, was isolated from a yellow water sample collected from the manufacturing process of strong flavor Chinese baijiu in Yibin region of Sichuan province (PR China). Oval endospores were formed at the subtermini of cells with swollen sporangia. The isolate was able to grow at temperatures of 20-45 °C (optimum growth at 37 °C), at pH 6.0-10.0 (optimum growth at pH 8.0) and in the presence of 0-2 % (w/v) NaCl (optimum growth with 0 % NaCl). Ribose was the major cell-wall sugar, and meso-diaminopimelic acid (meso-DAP) was the diagnostic amino acid. The main polar lipids of 3 H-10T included diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE). MK-7 was predominant menaquinone and iso-C15 : 0 (60.7 %) was the major fatty acid. Comparisons of 16S rRNA gene sequence indicated that 3 H-10T was most closely related to Bacillus mesophilus SA4T (96.30 %), Bacillus ginsengihumi Gsoil 114T (96.27 %) and Bacillus shackletonii LMG 18435T (96.27 %). The average nucleotide identity (ANI) values between strain 3 H-10T and the three type strains mentioned above were 69.56, 70.19 and 70.67 %, respectively. The genomic DNA G+C content was 35.4 mol%. On the basis of its phenotypic, chemotaxonomic and phylogenetic properties, strain 3 H-10T represents a novel species of the genus Bacillus, for which the name Bacillus aquiflavi sp. nov. is proposed. The type strain is Bacillus aquiflavi 3 H-10T (=CICC 24755T=JCM 33703T).


Assuntos
Bebidas Alcoólicas/microbiologia , Bacillus/classificação , Filogenia , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Água
3.
Food Chem ; 320: 126605, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32229395

RESUMO

Distillery fermentations are non-sterile, which allow bacterial communities to flourish, typically towards the end of fermentation. The effect of beginning the bacterial fermentation at the start of fermentation was investigated. Wort was treated for 48 h using a commercial strain of Lactobacillus plantarum followed by fermentation using a distilling strain of Saccharomyces cerevisiae. The treated wash showed a substantial increase in lactic, acetic and succinic acids Sensory analysis determined that the spirit produced with bacterial treatment were significantly different (p < 0.05) and chemical analysis demonstrated an increase in the production of ethyl acetate. These results show that pre-treatment using species of Lactobacillus could be utilised to alter the quality of new-make spirit in a distillery. By using bacterial cultures present in the surroundings or raw materials, distillers could allow naturally occurring or commercially available microflora to be added thus enhancing flavour development during fermentation and producing different spirit characters.


Assuntos
Acetatos/metabolismo , Bebidas Alcoólicas/microbiologia , Fermentação , Manipulação de Alimentos , Lactobacillus plantarum/metabolismo , Acetatos/análise , Microbiologia de Alimentos , Saccharomyces cerevisiae/metabolismo
4.
J Food Sci ; 85(3): 762-770, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31999368

RESUMO

Nuruk is a fermentation agent used to manufacture alcoholic beverages, which contains a variety of microorganisms. Most microorganisms in Nuruk are useful for the production of alcoholic beverages; however, Nuruk can be infected with Aspergillus flavus, which produces aflatoxin (AF). Therefore, this study analyzed total AF concentrations in Nuruk, the transfer of AF from Nuruk to alcoholic beverages, and AF-producing microorganisms to determine the safety of alcoholic beverages with respect to this toxin. ELISA showed that total AF levels in 14 of 61 Nuruk samples exceeded 15 ppb, the Korean permissible level in cereal products. In alcoholic beverages produced with Nuruk containing AF levels >15 ppb, only AF G1 was detected, at a level of 0.3 ppb, and the transfer ratio of AF G1 was approximately 1.2% to 1.3%. The dominant genera in Nuruk were Aspergillus and Rhizopus. Among 30 strains belonging to Aspergillus, 10 produced only AF B1 at levels of 0.1 to 2.4 ppb after incubation at 25 °C for 8 days on potato dextrose agar plates. Although AF in Nuruk was rarely transferred to alcoholic beverages and the aflatoxigenic strains were found to possess poor AF-producing capacity, further efforts to reduce AF in Nuruk are needed to ensure the safety of alcoholic beverages.


Assuntos
Aflatoxinas/análise , Bebidas Alcoólicas/análise , Aflatoxinas/metabolismo , Bebidas Alcoólicas/microbiologia , Aspergillus flavus/metabolismo , Grão Comestível/química , Grão Comestível/metabolismo , Grão Comestível/microbiologia , Fermentação , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Rhizopus/metabolismo , Amido/análise , Amido/metabolismo
5.
J Agric Food Chem ; 68(5): 1419-1426, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31888328

RESUMO

Sake, the Japanese rice wine, contains a variety of oligosaccharides and glucosides produced by fungal enzymes during the brewing process. This study investigates the effect of knocking out the Aspergillus oryzae α-glucosidase (agdA) gene on the transglycosylation products in brewed sake. In addition to α-ethyl glucoside and α-glyceryl glucoside, the amount of two compounds that have molecular mass values similar to that of ethyl maltose decreased by agdA gene knockout. Both compounds were synthesized, in vitro, from maltose and ethanol with purified agdA. Nuclear magnetic resonance analysis identified the two compounds as ethyl α-maltoside and ethyl α-isomaltoside, respectively, which are novel compounds in sake as well as in the natural environment. Quantitative analysis of 111 commercially available types of sake showed that these novel compounds were widely present at concentrations of several hundred mg/L, suggesting that both of them are ones of the common glycosides in sake.


Assuntos
Bebidas Alcoólicas/microbiologia , Aspergillus oryzae/enzimologia , Proteínas Fúngicas/metabolismo , Glicosídeos/metabolismo , alfa-Glucosidases/metabolismo , Bebidas Alcoólicas/análise , Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Etanol/metabolismo , Fermentação , Proteínas Fúngicas/genética , Glicosídeos/química , Glicosilação , Maltose/metabolismo , Oryza/metabolismo , Oryza/microbiologia , alfa-Glucosidases/genética
6.
J Biosci Bioeng ; 129(1): 1-5, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31515157

RESUMO

Folates are important vitamins in human nutrition. Pressed sake cake, a brewing by-product of sake, is a rich dietary source of folates derived from sake yeast (Saccharomyces cerevisiae). The National Research Institute of Brewing investigated 106 samples of pressed sake cake and revealed that three samples containing large amounts of folates were produced by Km67 yeast derived from the house sake yeast strain of Kiku-Masamune sake brewery. In this study, we performed sake brewing tests using Km67 and Kyokai no. 7 group strains and confirmed that Km67 yeast contributed to the production of pressed sake cake containing large amounts of folates. To elucidate the mechanisms of high folate accumulation in Km67, we performed whole-genome sequence analysis in Km67 and then screened 10 folate-metabolizing genes showing different sequences in Km67 and K7 strains. By folate analysis of each gene-disrupted strain derived from strain BY4743, we also selected four genes having significant effects on folate content in yeast from 10 candidate genes. Folate analysis of gene-disrupted yeast strains complemented with either Km67-type genes or K7-type genes revealed that the Km67-type HMT1 gene was related to high folate accumulation not only in laboratory yeast but also in sake yeast. In this gene, Leu63Phe was present in the methyltransferase motif I of Hmt1p, which was essential for the methyltransferase activity of Hmt1p. Our results and previous reports suggested that the methyltransferase activity of Km67-Hmt1p was higher than that of K7-Hmt1p, leading to enhanced production and high accumulation of folates in Km67 yeast.


Assuntos
Ácido Fólico/metabolismo , Saccharomyces cerevisiae/metabolismo , Bebidas Alcoólicas/análise , Bebidas Alcoólicas/microbiologia , Fermentação , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
7.
Arch Microbiol ; 202(2): 299-308, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31654112

RESUMO

Huangjiu is one of the Chinese unique and traditional liquor. Corn is a kind of high yield crop in China, which has the characteristics of wide distribution, low price and high starch content. Fermenting Huangjiu with corn not only enrich Huangjiu types, but also opens up a new way for the utilization of corn. The flavor compounds and microorganisms in corn wine fermentation were studied in this study. A total of 98 volatile compounds and 8 kinds of organic acids were detected. Bacillus, Weissella, Streptomyces, Aeromonas and Blautia were the dominant bacteria. The correlation analysis between flavor compounds and bacteria showed that there were 557 correlations between major flavor compounds and bacteria. Among them, Lactococcus, Virgibacillus, Sphingobacterium and Sporolactobacillus were dominant genus of flavor producing bacteria. This study may reveal the changing rule of bacteria in Huangjiu, predict the relationship between metabolites and bacteria. In addition, this study expanded the application of corn and increased the variety of Huangjiu.


Assuntos
Bebidas Alcoólicas/microbiologia , Bactérias/metabolismo , Alimentos e Bebidas Fermentados/microbiologia , Zea mays/metabolismo , Bactérias/classificação , Bactérias/isolamento & purificação , Reatores Biológicos , China , Fermentação , Paladar , Compostos Orgânicos Voláteis/análise , Vinho/análise , Zea mays/microbiologia
8.
Int J Food Microbiol ; 318: 108471, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-31841786

RESUMO

This work presents the attempt to enhance the flavor complexity of cider fermented by different non-Saccharomyces species. Pichia kluyveri and Hanseniaspora vineae pure cultures were used as reference ciders. Mixed cultures between all 4 species gave 5 fermentations, where Hanseniaspora uvarum or Torulaspora quercuum were included for apple juice fermentation. Chemical composition and sensorial properties of all ciders were studied. The results indicated that the growth of P. kluyveri and H. vineae were interreacted and also affected by H. uvarum and T. quercuum. H. vineae was more capable of consuming sugar than P. kluyveri. Ciders from the single culture fermentation with P. kluyveri (Pk), as well as from mixed fermentation with P. kluyveri and H. uvarum (Pk-Hu), had high residual sugar, sugar/acid ratio, and glucose-fructose consumption ratio. Large shifts in the consumption and production of organic acids and polyphenols among all ciders were observed. The calculation of the relative odor activity value (rOAV) showed that 17 volatile compounds had an rOAV >1 in at least one sample, and acetate esters and ethyl esters were the groups with the highest number of volatile compounds of importance to the cider aroma. Among these 17 compounds, 3-methylbutyl acetate, 2-methylbutyl acetate, ethyl hexanoate, ethyl octanoate, and ß-damascenone exhibited high rOAVs in some ciders and might contribute fruity, floral, and sweet features to the cider aroma. Besides, the tropical fruity aroma from 3-methylbutyl acetate was only perceived in Pk and Pk-Hu. The partial least squares regression (PLSR) analysis revealed that acetate esters contributed positively to the roasted and cooked odor of all ciders. This is the first study evaluating simultaneous fermentation of two non-Saccharomyces yeasts to produce cider, which provides new insights into cider production.


Assuntos
Bebidas Alcoólicas/análise , Bebidas Alcoólicas/microbiologia , Saccharomycetales/metabolismo , Reatores Biológicos/microbiologia , Fermentação , Aromatizantes/análise , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Malus , Odorantes/análise , Saccharomycetales/classificação , Saccharomycetales/crescimento & desenvolvimento , Especificidade da Espécie , Paladar
9.
Food Microbiol ; 86: 103339, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703886

RESUMO

The study of microbial communities associated with spontaneous fermentation of agave juice for tequila production is required to develop starter cultures that improve both yield and quality of the final product. Quantification by HPLC of primary metabolites produced during the fermentations was determined. A polyphasic approach using plate count, isolation and identification of microorganisms, denaturing gradient gel electrophoresis and next generation sequencing was carried out to describe the diversity and dynamics of yeasts and bacteria during small-scale spontaneous fermentations of agave juice from two-year samplings. High heterogeneity in microbial populations and fermentation parameters were observed, with bacteria showing higher diversity than yeast. The core microorganisms identified were Saccharomyces cerevisiae and Lactobacillus fermentum. Practices in tequila production changed during the two-year period, which affected microbial community structure and the time to end fermentation. Bacterial growth and concomitant lactic acid production were associated with low ethanol production, thus bacteria could be defined as contaminants in tequila fermentation and efforts to control them should be implemented.


Assuntos
Bebidas Alcoólicas/microbiologia , Bactérias/metabolismo , Leveduras/isolamento & purificação , Agave/química , Agave/microbiologia , Bebidas Alcoólicas/análise , Bactérias/química , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Etanol/metabolismo , Fermentação , Cinética , Lactobacillus fermentum/química , Lactobacillus fermentum/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Leveduras/química , Leveduras/genética , Leveduras/metabolismo
10.
Biosci Biotechnol Biochem ; 84(4): 842-853, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31868109

RESUMO

General sake yeasts (e.g., Kyokai no.7, K7) show high fermentation ability and low sporulation frequency. Former is related to stress-response defect due to the loss-of-function of MSN4 and RIM15. Later is mainly caused by low IME1 expression, leading to difficulty in breeding and genetic analysis. Sake yeast Hiroshima no.6 (H6), which had been applied for sake fermentation, has sporulation ability. However, its detailed properties have not been unveiled. Here we present that the fermentation ability of H6 is suitable for sake brewing, and the precursor of dimethyl trisulfide in sake from H6 is low. MSN4 but not RIM15 of H6 has the same mutation as K7. Our phylogenetic analysis indicated that H6 is closely related to the K7 group. Unlike K7, H6 showed normal sporulation frequency in a partially RIM15-dependent manner, and IME1 in H6 was expressed. H6 possesses excellent properties as a partner strain for breeding by crossing.


Assuntos
Bebidas Alcoólicas/microbiologia , Fermentação , Saccharomyces cerevisiae/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Cruzamentos Genéticos , Genes Fúngicos , Filogenia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Proteínas de Saccharomyces cerevisiae/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-31766289

RESUMO

Improper handling, poor hygienic practices, and lack of environmental control affect the safety of street-vended beverages. The objective of this study is to determine the bacterial contamination level of three types of beverages (cordial-based drinks, milk-based drinks, fruit juices) sold by street vendors at Chow Kit, Kuala Lumpur. A total of 31 samples of beverages were analyzed to determine total viable count (TVC), total coliform, Escherichia coli, and Staphylococcus aureus counts via the standard plate count method. The results showed that only 9.7% of the total samples were not contaminated with the tested microorganisms. All milk-based drink samples were positive for TVC and also had the highest average bacterial counts at 5.30 ± 1.11 log Colony Forming Unit/mL (CFU/mL). About 71% of the samples were contaminated with total coliform with the average readings ranging between 4.30 and 4.75 log CFU/mL, whereas 58.1% of the samples were positive with S. aureus, with fruit juices having the highest average reading (3.42 ± 1.15 log CFU/mL). Only one sample (milk-based drink) was E. coli positive. This study showed that the microbiological safety level of street-vended beverages in Chow Kit, Kuala Lumpur was average and needs to be improved. Provision of food safety education and adequate sanitary facilities at vending sites are suggested to increase the safety of food products.


Assuntos
Bebidas Alcoólicas/microbiologia , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Serviços de Alimentação , Sucos de Frutas e Vegetais/microbiologia , Leite/microbiologia , Animais , Carga Bacteriana , Cidades , Comércio , Monitoramento Ambiental , Escherichia coli/isolamento & purificação , Manipulação de Alimentos , Inocuidade dos Alimentos , Malásia , Staphylococcus aureus/isolamento & purificação
12.
J Agric Food Chem ; 67(38): 10694-10701, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31476866

RESUMO

Too large of a higher alcohol content has negative effects on the liquor taste and health. Revealing the key microbes and their key driving forces is essential to regulate the higher alcohol content in spontaneous liquor fermentation. Herein, we used high-throughput sequencing associated with a multivariate statistical algorithm to reveal the contributing microbes for higher alcohol production in Chinese light-aroma-type liquor and identified that Saccharomyces and Pichia were the main contributors. In addition, the C/N ratio and microbial interaction were found to significantly affect the production of higher alcohols. Herein, we used response surface methodology to establish a predictive model for higher alcohol production with the regulating factors, and the content of total higher alcohols decreased significantly from 328.80 ± 24.83 to 114.88 ± 5.02 mg/L with the optimized levels of the regulators. This work would facilitate the control of flavor production via regulating microbial communities in food fermentation.


Assuntos
Bebidas Alcoólicas/microbiologia , Álcoois/metabolismo , Interações Microbianas , Pichia/fisiologia , Saccharomyces/fisiologia , Bebidas Alcoólicas/análise , Álcoois/análise , Aromatizantes/metabolismo
13.
Int J Syst Evol Microbiol ; 69(9): 2709-2716, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31310191

RESUMO

Moutai-flavour Daqu is an important starter to support growth of microorganisms in the fermented process of Moutai-flavour liquor. A novel thermophilic microorganism, designated strain FBKL4.011T, was isolated from Moutai-flavour Daqu samples collected from Guotai distillery in Renhuai, Guizhou province, south-west China. The strain could grow at 45-65 °C (optimum 45 °C). Based on polyphasic analysis, strain FBKL4.011T was affiliated to the genus Thermoflavimicrobium. It formed abundant pale-yellow aerial and substrate mycelium, bearing single endospores (7.0-10.0 µm diameter) on branched long sporophores (5.0 µm diameter). The cell-wall peptidoglycan contained meso-diaminopimelic acid; ribose, glucose and mannose were the primary whole-cell sugars. The major fatty acids were iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. The predominant menaquinone were MK-8 and MK-9. The polar phospholipids contained diphosphatidyl glycerol, phosphatidyl ethanolamine, one unidentified phospholipid and one unidentified lipid. The G+C content of the genome was 43.1 mol%. According to the 16S rRNA gene sequence analysis, strain FBKL4.011T was closely related to Thermoflavimicrobium dichotomicum JCM 9688T (95.3 % sequence similarity), and other members within the family Thermoactinomycetaceae (less than 93.0 % sequence similarity). The DNA-DNA hybridisation data showed low relatedness between strain FBKL4.011T and T. dichotomicum JCM 9688T, Laceyella sacchari KCTC 9790T, Laceyella tengchongensis YIM 10002T, Laceyella sediminis RHA1T(36.7±1.1 %, 30.0±1.2 %, 21.3±2.1 % % and 37.6±0.9 %, respectively). Based on data from the polyphasic analysis, strain FBKL4.011T is considered to represent a novel species of the genus Thermoflavimicrobium, for which the name Thermoflavimicrobium daqui sp. nov. is proposed. The type strain is FBKL4.011T(=KCTC 43036T=CICC 24504T).


Assuntos
Bebidas Alcoólicas/microbiologia , Bacillales/classificação , Filogenia , Bacillales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos , Vitamina K 2/química
14.
J Microbiol ; 57(10): 836-841, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31250399

RESUMO

A Gram-stain-positive, rod-shaped, non-endospore-forming motile by means of peritrichous flagella, facultatively anaerobic bacterium designated TI45-13arT was isolated from Nuruk, a Korean traditional Makgeolli fermentation starter. It grew at 4-35°C (optimum, 28-30°C), pH 5.0-9.0 (optimum, pH 7.0) and NaCl concentrations up to 5% (w/v). Phylogenetic trees generated using 16S rRNA gene sequences revealed that strain TI45-13arT belonged to the genus Paenibacillus and showed the highest sequence similarities with Paenibacillus kyungheensis DCY88T (98.5%), Paenibacillus hordei RH-N24T (98.4%) and Paenibacillus nicotianae YIM h-19T (98.1%). The major fatty acid was anteiso-C15:0. The DNA G+C content was 39.0 mol%, and MK-7 was the predominant isoprenoid quinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified glycolipids, and one unidentified aminoglycolipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid. On the basis of polyphasic taxonomy study, it was suggested that strain TI45-13arT represents a novel species within the genus Paenibacillus for which the name Paenibacillus nuruki sp. nov. is proposed. The type strain was TI45-13arT (= KACC 18728T = NBRC 112013T).


Assuntos
Bebidas Alcoólicas/microbiologia , Alimentos e Bebidas Fermentados/microbiologia , Paenibacillus/classificação , Paenibacillus/isolamento & purificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Paenibacillus/genética , Paenibacillus/metabolismo , Filogenia , RNA Ribossômico 16S/genética , República da Coreia , Cloreto de Sódio/análise , Cloreto de Sódio/metabolismo
15.
Proc Natl Acad Sci U S A ; 116(26): 12767-12774, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31160461

RESUMO

In China, pottery containers first appeared about 20000 cal. BP, and became diverse in form during the Early Neolithic (9000-7000 cal. BP), signaling the emergence of functionally specialized vessels. China is also well-known for its early development of alcohol production. However, few studies have focused on the connections between the two technologies. Based on the analysis of residues (starch, phytolith, and fungus) adhering to pottery from two Early Neolithic sites in north China, here we demonstrate that three material changes occurring in the Early Neolithic signal innovation of specialized alcoholic making known in north China: (i) the spread of cereal domestication (millet and rice), (ii) the emergence of dedicated pottery types, particularly globular jars as liquid storage vessels, and (iii) the development of cereal-based alcohol production with at least two fermentation methods: the use of cereal malts and the use of moldy grain and herbs (qu and caoqu) as starters. The latter method was arguably a unique invention initiated in China, and our findings account for the earliest known examples of this technique. The major ingredients include broomcorn millet, Triticeae grasses, Job's tears, rice, beans, snake gourd root, ginger, possible yam and lily, and other plants, some probably with medicinal properties (e.g., ginger). Alcoholic beverages made with these methods were named li, jiu, and chang in ancient texts, first recorded in the Shang oracle-bone inscriptions (ca. 3200 cal. BP); our findings have revealed a much deeper history of these diverse fermentation technologies in China.


Assuntos
Bebidas Alcoólicas/história , Utensílios de Alimentação e Culinária/história , Fermentação , Bebidas Alcoólicas/microbiologia , Grão Comestível/química , Manipulação de Alimentos/história , Fungos/metabolismo , História Antiga , Humanos
16.
J Sci Food Agric ; 99(13): 5792-5798, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31162672

RESUMO

BACKGROUND: Recently, a producer of fermented ciders observed 'vinyl' off-odors formed during fermentation of pear juice previously depectinized at ≥ 49 °C but not if depectinized at lower temperatures. The objective of this study was to investigate the source of this spoilage and evaluate factors that affect formation. RESULTS: Analysis of untainted and tainted samples obtained from the producer determined the causative agent to be indole, a compound sometimes produced by yeast (Saccharomyces cerevisiae) during fermentation. To mimic commercial depectinization conditions, pectinases were added to pear juices held at 35 °C for 45 min (Treatment A), 49 °C for 45 min (Treatment B), or 49 °C for 90 min (Treatment C). Juice processing conditions did not affect yeast growth nor progress of alcoholic fermentation. Although neither yeast strain (DV10 or MERIT) synthesized indole during fermentation of Treatment A juices, the compound was produced by MERIT in Treatments B (27.05 µg L-1 ) and C (469.9 µg L-1 ). Supplementation of Treatment C juice with pyridoxine (vitamin B6 ) prior to fermentation resulted in no detectable indole formed. However, juices from Treatments A, B, or C contained similar concentrations of pyridoxine and non-detectable amounts of tryptophan, a potential precursor to indole. Furthermore, indole was not detected during fermentations of a synthetic pear juice medium without pyridoxine. CONCLUSION: Supplementation of cider musts with pyridoxine prior to fermentation and choice of yeast strain can lower the risk of formation of off-odors caused by indole. However, other unidentified factors are present which affect its formation in perry. © 2019 Society of Chemical Industry.


Assuntos
Bebidas Alcoólicas/análise , Etanol/metabolismo , Manipulação de Alimentos/métodos , Indóis/metabolismo , Pectinas/metabolismo , Pyrus/química , Saccharomyces cerevisiae/metabolismo , Bebidas Alcoólicas/microbiologia , Etanol/análise , Fermentação , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Indóis/análise , Malus/química , Malus/microbiologia , Odorantes/análise , Poligalacturonase/química , Pyrus/microbiologia
17.
Int J Food Microbiol ; 303: 1-8, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31102962

RESUMO

To obtain beverages with reduced alcohol content, the use of unripe grapes, with low sugar and high malic acid concentration, was recently explored. Due to the low sugar, ethanol and glycerol production is limited during fermentation affecting important sensory aspects such as the palate fullness of these beverages. The high acidity influences their organoleptic quality, as well. So far, only S. cerevisiae starter, used in conventional fermentations, have been tested in this condition, and no selection has been performed to identify alternative yeasts suitable for unripe grape fermentation. S. bacillaris is known for the low ethanol tolerance, high glycerol and moderate volatile acidity production. Therefore, this non- Saccharomyces yeast have been investigated to improve the quality of low-alcohol beverages. Seven S. bacillaris strains were tested in synthetic musts with different sugar and malic acid levels, mimicking natural ripe and unripe grape musts. In all the tested conditions, S. bacillaris produced higher glycerol than S. cerevisiae. In single-strain fermentation at low sugar and high malic acid no S. bacillaris strains was able to transform all the sugars, although the produced ethanol was lower than that at high sugar condition. Therefore, sequential fermentations with S. cerevisiae were evaluated at low sugar and high malic acid. In this condition all the sugars were consumed and a significant glycerol increase was found. These results were confirmed when sequential fermentations were run in natural unripe grape must. Moreover, an increase in malic acid degradation, with respect to EC1118 single-strain fermentation, was observed.


Assuntos
Bebidas Alcoólicas/microbiologia , Fermentação , Microbiologia de Alimentos , Saccharomycetales/metabolismo , Vitis/microbiologia , Etanol/metabolismo , Glicerol/metabolismo , Malatos/metabolismo , Saccharomyces cerevisiae/metabolismo , Vitis/metabolismo , Vinho/microbiologia
18.
J Appl Microbiol ; 127(3): 750-762, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30989782

RESUMO

AIMS: Microorganisms in fermentation pits (FPs) play key roles for Chinese-strong-aromatic-liquor (CSAL) production. However, the microbial community in the FPs is still poorly understood. Here, the aim of this study was to reveal the diversity and potential functions of microbiota in FPs. METHODS AND RESULTS: Sequencing-by-synthesis-based metagenomic sequencing and annotation results revealed that the microbiota of FPs was primarily composed of Firmicutes (54·6%), Euryarchaeota (15·3%), Bacteroidetes (10·1%), Gammaproteobacteria (5·8%), Opisthokonta (5·7%) and Unclassified_Bacteria (2·3%). And 133 genera were identified as the dominant genera of this fermentative food. Lactobacillus, Sedimentibacter, Syntrophomonas, Methanoculleus, Methanobacterium, Bacillus, Clostridium, Galactomyces, Candida, Pichia, Penicillium and Aspergillus were defined as active populations for biosynthesizing the characteristic volatile compounds of CSAL. The study also revealed that the microbial community structures changed significantly with different cellar ages and over different geographical regions. (i) The presence of Bacteroidetes was the most distinctive feature that characterized the different FPs ages. (ii) Distinct contents of Gammaproteobacteria and Euryarchaeota were observed at different positions in the FPs. (iii) Euryarchaeota markedly contributed to the generation of the character of the liquors with distinct geographical associations. CONCLUSIONS: This study demonstrated that the changes of microbial communities determined the different quality characteristics of CSAL. SIGNIFICANCE AND IMPACT OF THE STUDY: This research contributes to a deeper understanding of the FPs microbial composition and shows a new microbial resource for biotechnological applications.


Assuntos
Bebidas Alcoólicas/microbiologia , Bactérias/classificação , Fermentação , Microbiota/genética , Bactérias/genética , China , Metagenômica , Análise de Sequência de DNA
19.
Food Microbiol ; 82: 294-302, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027786

RESUMO

The aim of this study was to analyze the microbiology of buckwheat honey fermentation inoculated with different starter cultures by culturing and PCR-DGGE, taking as a model for comparison a spontaneously fermented batch. The inoculants tested were (i) cider lees (from a cider factory), (ii) sourdough (from a bakery), and (iii) a commercial Saccharomyces cerevisiae strain. The results of the culturing and culture-independent techniques agreed well and detected the same dominant species along the fermentations. Our results suggest that S. cerevisiae strains, which constituted a majority population in all batches including the uninoculated one, carried out the fermentations. The highest microbial diversity was found at the beginning of the fermentation in the uninoculated batch; this contained in addition to S. cerevisiae bacteria (Paracoccus sp., Staphylococcus sp., and Bacillus sp.) and yeast (Candida sp.) species. Candida sp. was also common in batches inoculated with sourdough and cider lees cultures. Lactobacillus species were found throughout the fermentation of the sourdough-inoculated batch. Basic chemical analysis and testing trials demonstrated that the overall sensory acceptance of the four meads were highly similar. Yeast and bacteria isolated in this study could serve as a source of technologically relevant microorganisms for mead production.


Assuntos
Bebidas Alcoólicas/microbiologia , Fagopyrum , Mel/microbiologia , Microbiota , Bebidas Alcoólicas/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodiversidade , Pão/microbiologia , Candida/classificação , Candida/genética , Candida/isolamento & purificação , Candida/metabolismo , Contagem de Colônia Microbiana , Etanol/análise , Fermentação , Microbiologia de Alimentos , Mel/análise , Microbiota/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Paladar
20.
Food Microbiol ; 82: 398-408, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027799

RESUMO

We previously reported the isolation a suite of wild lactic acid-producing yeasts (LAYs) that enable "primary souring" during beer fermentation without the use of lactic acid bacteria. With sour meads gaining popularity in modern mead making, we were interested in exploring the same primary souring approach to traditional semi-sweet meads. In this study, we utilized 13 LAY strains to produce semi-sweet meads using a standardized batch of honey must to ensure consistent starting conditions. Thirteen 11-L batches of mead were prepared, and each was inoculated with one of the LAY strains, along with two control batches inoculated with champagne yeast. The initial pH and specific gravity were measured for each batch before inoculation. Traditional organic staggered nutrient addition was utilized for the first 72 h of fermentation with specific gravities being taken throughout the mead making process. Meads were racked, tasted, stabilized, cold crashed, bottled, and transported to the American Mead Maker's Association 2018 Conference in Broomfield, Colorado. There, organoleptic surveys were conducted on these meads utilizing an array of tasters with varying levels of mead sensory analysis experience. The results of the sensory analysis, focusing on aroma and flavor, are discussed.


Assuntos
Bebidas Alcoólicas/análise , Bebidas Alcoólicas/microbiologia , Microbiologia de Alimentos , Ácido Láctico/metabolismo , Saccharomyces cerevisiae/metabolismo , Sensação/fisiologia , Bebidas Alcoólicas/normas , Fermentação , Mel/análise , Mel/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Odorantes/análise , Inquéritos e Questionários , Paladar
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