Monday, May 4, 2009
9-59
Performances of Lactobacillus brevis for producing lactic acid from hydrolysate of lignocellulosics
Wei Guo1, Yin Li1, Shulin Chen2, and Wendi Jia1. (1) Institute of Microbiology, Chinese Academy of Sciences, Room A214, Datun Road, Beijing, China, (2) Biological System Engineering, Washington State University, L.J. Smith 213, Pullman, WA 99163
Utilizing all forms of sugars derived from lignocellulosic biomass via various pretreatment and hydrolysis process is a primary criterion for selecting a microorganism to produce biofuels and biochemicals. With dilute acid hydrolysis technology, the broad carbon spectra and potential inhibitors such as furan, phenol compounds and weak acid to microorganism are the two major obstacles that limited the application of dilute-acid hydrolysate of lignocellulose in ethanol and lactic acid fermentation. Two strains S3F 4 (Lactobacillus brevis) and XS1T3-4 (Lactobacillus plantrum) isolated from sour cabbage, exhibited the ability to utilize various sugars presented in dilute-acid hydrolysate of lignocellulose. The S3F 4 strain also showed strong resistance ability to the potential fermentation inhibitors, ferulic acid and furfural. Shake-flask fermentation indicated that 39.1 g/l of lactic acid could be produced by S3F 4 from dilute acid hydrolysates of corn cob with 56.9 g/l total sugars (xylose, 46.4 g/l; glucose, 4.0 g/l, arabinose, 6.5 g/l). The hydrolysate of corn cob could be readily utilized by S3F 4 without detoxification, and the lactic acid concentration in the fermentation broth was higher compared to other reports.