Correlation of the bacterial communities with umami components, and chemical characteristics in Zhejiang xuecai and fermented brine

•Total protein, sugar, amino acids and organic acids had a higher content in brine.•Lactobacillus, Halanaerobium and Halomonas were the main genera in xuecai and brine.•Halophilic bacteria had a positive effect on umami components in xuecai and brine.•Carbohydrate metabolism and amino acid metabolism were the most abundant pathway.