Improved production of Acetone-Butanol-Ethanol (ABE) by genome shuffling of Clostridium acetobutylicum CICC 8012

摘要

Genome shuffling was described as a process combining the advantage of multi-parental crossing allowed by DNA shuffling with the recombination of entire genomes normally associated with conventional breeding, and as an efficient method for evolution of strains toward desirable phenotypes. This method had been widely applicable to the improvement of most production pathways in microorganisms.Here, researchers describe its application to improve the production of ABE in Clostridium acetobutylicum CICC 8012. The best performing strain, named as F2-GA, was isolated after two rounds of genome shuffling. The ABE production of F2-GA reached to 22.21 g/l (containing 2.35 g ethanol/l, 5.71 g acetone/I and 14.15 g butanol/l) and was 34.28 °/o higher than that of the wild type. Gene expression of several key enzymes in ABE metabolic pathways was altered significantly compared with those ofthe wild type. Meanwhile, fermentation with the continuous subculture of F2-GA revealed it had a good genetic stability, which would be useful for scale-up of ABE fermentation.