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Identification of key micro‐organisms involved in Douchi fermentation by statistical analysis and their use in an experimental fermentation
Author(s) -
Chen C.,
Xiang J. Y.,
Hu W.,
Xie Y. B.,
Wang T. J.,
Cui J. W.,
Xu Y.,
Liu Z.,
Xiang H.,
Xie Q.
Publication year - 2015
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12917
Subject(s) - fermentation , food science , biology , temperature gradient gel electrophoresis , statistical analysis , bacteria , 16s ribosomal rna , statistics , genetics , mathematics
Aims To screen and identify safe micro‐organisms used during Douchi fermentation, and verify the feasibility of producing high‐quality Douchi using these identified micro‐organisms. Methods and Results PCR ‐denaturing gradient gel electrophoresis ( DGGE ) and automatic amino‐acid analyser were used to investigate the microbial diversity and free amino acids ( FAA s) content of 10 commercial Douchi samples. The correlations between microbial communities and FAA s were analysed by statistical analysis. Ten strains with significant positive correlation were identified. Then an experiment on Douchi fermentation by identified strains was carried out, and the nutritional composition in Douchi was analysed. Results showed that FAA s and relative content of isoflavone aglycones in verification Douchi samples were generally higher than those in commercial Douchi samples. Conclusions Our study indicated that fungi, yeasts, Bacillus and lactic acid bacteria were the key players in Douchi fermentation, and with identified probiotic micro‐organisms participating in fermentation, a higher quality Douchi product was produced. Significance and Impact of the Study This is the first report to analyse and confirm the key micro‐organisms during Douchi fermentation by statistical analysis. This work proves fermentation micro‐organisms to be the key influencing factor of Douchi quality, and demonstrates the feasibility of fermenting Douchi using identified starter micro‐organisms.