earticle

영어

Production of bio-based fuels and chemicals from renewable resources is becoming more important as fossil resources diminish and global climate changes threaten environmental safety and human life. One such chemical, 2,3-butanediol (2,3-BD) possesses a wide range of industrial applications, and its production by microbial fermentation has been extensively studied for more than 100 years. However, the secretion of mucoid substances by Klebsiella pneumoniae, a natural 2,3-BD hyper-producer, hinders its application in large-scale fermentation because of pathogenicity, fermentation instability, and downstream difficulty. In this study, a number of mucoid-free K. pneumoniae strains were isolated from a waste water treatment plant, and their lactate dehydrogenase (ldhA-) mutants were made using pKOV plasmid which was originally developed for Escherichia coli. Fed-batch fermentation of the mutants resulted in the production of 2,3-BD at more than 70 g l-1 with an 2,3-BD yield of 0.40 g g-1 glucose. These results strongly suggest that the newly isolated mucoid-free K. pneumoniae strains have a great potential for industrial 2,3-BD production.