Abstract: In order to screen and identify hexanoic acid-producing anaerobic bacteria with high yield from liquor pit mud and to apply it in maintaining pits or artificial pit mud. The hexanoic acid-producing anaerobic strains with high yield were isolated and selected from the fine pit mud of the distillery in the northeast area by facultative anaerobic culture and trace component analysis. The yields of hexanoic acid were up to 213.6914, 170.465 mg/100 mL and 103.5097 mg/100 mL, respectively. The species identification showed that three strains were Bacillus fusiformis, Bacillus licheniformis and Bacillus megaterium, respectively, through morphological observation, physiological and biochemical tests and molecular biology methods. The optimal pH was 7, 6.5 and 7 and the optimal temperatures were 34, 34 ℃ and 37 ℃ as well as the optimal inoculums were 5%, 5% and 3%. This study provides a theatrical guidance for the application of efficiently artificial pit mud.

Key words: Luzhou-flavor liquor, pit mud, hexanoic acid-producing bacteria, identification