Enhanced Solvents Production in Consolidated Bioprocessing Consortia By Promotion of Metabolites Exchange Via Modules Metabolic Engineering | AIChE

Enhanced Solvents Production in Consolidated Bioprocessing Consortia By Promotion of Metabolites Exchange Via Modules Metabolic Engineering

Authors 

Li, Q., Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China

No natural microorganism or microbial community can produce butanol directly from lignocellulose. Assembly of modules involved in lignocellulose saccharification and butanol synthesis into one host strain failed to accomplish the long pathway construction and keep overall cellular health simultaneously. Therefore, artificial microbial consortium consisting of celluloytic and solventogenic clostridia was designed for division and coordination of metabolic labor.

Recently, we developed a synthetic CBP consortia for cellulosic butanol production, in which, C. cellulovorans decomposed AECC (alkali-extracted deshelled corn cobs) and provided fermentable sugars and organic acids for C. beijerinckii to produce butanol. Herein, we developed the genetic system of C. cellulovorans and then reconstructed the CBP consortia. The overall across species pathway was divided into four modules including butyrate synthesis and NADH redirection modules in C. cellulovorans, and butyrate reassimilation and pentose utilization modules in C. beijerinckii. The metabolites (mainly butyrate) exchange was promoted significantly by reinforcing butyrate supply by C. cellulovorans and butyrate reutilization in C. beijerinckii simultaneously via module metabolic engineering and consequently enhanced solvents production.

In 110 h, the optimal CBP consortia produced over 20 g/L solvents with AECC as sole carbon source, which approximated ABE output from starchy feedstock. Our work severe as a stepping stone for industrial production of ABE from lignocellulose.