Metaproteomic analysis of microbiota in the fermented fish, Siniperca chuatsi

- A total of 2175 proteins from the microbiota in fermented fish was identified.
- Biological functions of the metaproteome were characterized.
- Streptococcus sp. and other strains were presumed to be flavour contributors.

The microbial community of spontaneously fermented fish plays an important role in product sensory quality. Recently, microbiota research has seen a shift in perspective from taxonomy to function. The investigation of the microbial community metaproteome will reveal information on strains as well as the expressed proteins to better understand the roles of the microbiota in fermented fish.In this study, shotgun metaproteomic methods were used to identify and annotate 2175 proteins from the traditional Chinese fermented fish Siniperca chuatsi. These proteins belonged to 553 bacterial strains of 19 phyla, including 10 strains of lactic acid bacteria. Based on the KEGG annotation system, 1217 proteins were found to be involved in metabolic pathways, among which 352 proteins were related to amino acid metabolism. Specifically, 63 amino acid degradation-related proteins were identified in Streptococcus sp., Bacillus sp., Escherichia sp., and Pseudoalteromonas sp., which indicated that these strains were potential candidates for generating aroma compounds and thus contributors to the special flavour of the fermented fish. This information on metaproteomes in fermented S. chuatsi increases the understanding of microbial metabolic modes and leads to knowledge-based improvements of the stability and palatability of fermented fish.