Proteomics and metagenomics reveal the relationship between microbial metabolism and protein hydrolysis in dried fermented grass carp using a lactic acid bacteria starter culture

A microbial starter culture is expected to improve the quality of traditional fermented fish products. Lactobacillus plantarum was selected for grass carp fermentation due to its high proteolytic activity. To investigate its effects on muscle proteolysis of dried fermented fish, the protein profile and microbial community were analysed by using proteomics and metabolomics. The myofibrillar protein and collagen profiles showed remarkable variation after processing, changes that were related to the development of flavour and texture in fish samples. The starter culture had a marked effect on the microbial composition. Macrococcus and Staphylococcus were the dominant genera, with a relative abundance of 24.79% and 12.53%, respectively. There were significant correlations (P < 0.05) between the dominant genera and the major peptidase genes and quality-related proteins. These findings suggest that microbial activity is involved in proteolysis and affects the flavour and texture of dried fermented fish.