Highly efficient Clostridium catalyst for butanol from non-grain sugars

Efficient cofermentation of glucose, xylose and arabinose, three major sugars present in lignocellulose, is a fundamental requirement for cost-effective utilization of lignocellulosic biomass. The Gram-positive anaerobic bacterium Clostridium acetobutylicum, known for its excellent capability of producing ABE (acetone, butanol and ethanol) solvent, is limited in utilizing lignocellulosic biomass because of the inefficient pentose (e.g. xylose) consumption.

Now a team of researchers at The Institute of Plant Physiology and Ecology (SIPPE), Shanghai Institutes for Biological Sciences (SIBS), CAS, have adopted a new engineering strategy for strain improvement. They attenuated glucose phosphoenolpyruvate-dependent phosphotransferase system (PTS) and overexpressed the xylose pathway enzymes, and gained the Clostridium strains capable of efficiently co-fermenting the mixture of glucose, xylose and arabinose, thus overcoming a technical bottleneck in lignocellulose-based butanol production. Dr. Wilf J. Mitchell of Heriot-Watt University also joined the research and finished measurement of the phosphotransferase activities of clostridial cells. A patent related to the research has been applied in China, which is expected to benefit the bioconversion of corn stover, bagasse, sweet sorghum stalk, and corncob.

The research is published online on September 16 in the Journal Applied and Environmental Microbiology. This research was supported by funding from National Basic Research Program of China, Knowledge Innovation Program of the Chinese Academy of Sciences, National Natural Science Foundation of China, and China Partnering Award of UK Biotechnology and Biological Sciences Research Council.

The research group, led by Prof. Weihong Jiang and Prof. Sheng Yang in SIPPE specialize in the biological butanol production, particularly in broadening substrate spectrum and improving butanol synthesis selectivity of C. acetobutylicum. During the past few years, the research group has published a series of biobutanol-related papers in the journals (e.g., BMC Genomics, Metabolic Engineering, Journal of Biotechnology). In the early half of 2011, they were invited to write a review about biobutanol manufacturing for the journal Biotechnology Journal.

AUTHOR CONTACT:
Yang Gu, Ph. D.
Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Telephone: +86-21-54924178, E-mail: ygu02@sibs.ac.cn