Butanediol production from glycerol and glucose by Serratia marcescens isolated from tropical peat soil

Abstract

Six bacterial strains , Bacillus subtilis LQOB-SE1, Bacillus coagulans LQOB-SE2, Bacillus pumilus LQOB-SE3, Brevibacillus brevis LQOB-SE4, Lysinibacillus sp. LQOB-SE5 and Serratia marcescens LQOB-SE6, isolated from a tropical peat soil , were assessed for 2,3-butanediol (2,3-BD) production by fermentation of glucose and glycerol. Only S. marcescens LQOB-SE6 strain was capable of producing 2,3-BD from both glucose and glycerol fermentation, and this process was optimized by changes in fermentation parameters. The best conditions for glycerol fermentation were initial pH 7.0, 8 g L −1 nutrient broth, 50 g L −1 substrate, and an incubation time of seven days, with 2,3-BD yield of 0.30 g g −1 , and productivity of 0.13 g L −1 h −1 . The best conditions for glucose fermentation were initial pH 7.0, 8 g L −1 nutrient broth, 75 g L −1 substrate, and an incubation time of five days, with 2,3-BD yield of 0.42 g g −1 and productivity of 0.15 g L −1 h −1 . meso -2,3-butanediol was the only stereoisomer obtained from glucose fermentation, while glycerol fermentation also produced smaller amounts of (2 R ,3 R )-2,3-butanediol. • Serratia marcescens strain from peat soil is capable of producing 2,3-butanediol. • The 2,3-butanediol production is influenced by fermentation parameters. • Glucose fermentation yielded only the meso -2,3-butanediol stereoisomer. • Glycerol fermentation yielded both meso -2,3-butanediol and (2 R ,3 R )-2,3-butanediol. • The ratio of stereoisomers varies accordingly the fermentation time.