Metagenomic analysis of microbial-community structure and function during the fermentation of suansun, a Chinese traditional bamboo shoot

Suansun is a Chinese fermented bamboo shoot product with unique stinky odor. In our previous, we have revealed the key aroma components that endowed the unique flavor of traditional suansun. However, the functional microbiota and how their metabolism affects flavor formation during suansun fermentation remained unclear. Thus, combined with results for the characteristic flavor substances formed during suansun fermentation in our previous study, samples from three representative stages during suansun fermentation were selected for metagenomic sequencing in this study, to understand the influence of microbial metabolism on the flavor formation of suansun. Results showed that the functional genes are mainly associated with carbohydrate metabolism and amino acid metabolism. Pyruvate and acetyl-coA were the key compounds in the whole microbial metabolic network, which promoted the conversion between different compounds. Analysis about distribution of microbes in different flavor biosynthesis pathways showed that ten genera, namely, Lactobacillus, Lactococcus, Leuconostoc, Clostridium, Enterobacter, Klebsiella, Kluyvera, Burkholderia, Leclercia, and Enterococcus, were the key microorganisms contributing to the production of main characteristic flavor substances of suansun. These results may contribute to novel insights into the functional microbial resources and might be helpful for the development of novel defined starter cultures to promote technological advances in the traditional suansun industry.