[Composition and distribution of yeasts at different fermentation stages for Maotai-flavor Chinese liquor production].

OBJECTIVE

In order to collect basic data for the analysis of metabolic mechanism, the composition and distribution patterns of yeasts at different fermentation stages for Maotai-flavor Chinese liquor production.

METHODS

By using plate screening techniques, a large number of yeast cultures were obtained from fermenting grains. Based on 26S rDNA D1/D2 region sequencing, the yeasts were identified. According to quantitative change, species composition, relative frequency, diversity indices and similarity coefficients, the composition and distribution patterns of yeasts were studied.

RESULTS

The numbers of yeasts in fermenting grains showed a rule of "higher-lower-higher-lower". A total of 13 species, 8 genera of the yeasts were identified. The whole diversity index of the yeasts was comparatively high. That the similarity coefficient in most cases was significantly higher than 0.5 showed that the species composition and distribution of yeasts were relatively stable. Issatchenkia orientalis, Pichia kudriavzevii and Saccharomyces cerevisiae play a very important role in the process of liquor fermentation.

CONCLUSION

There were abundant yeast resources in fermenting grains of maotai-flavor liquor.