Lee, Jungseok Saddler, Jack N. Um, Youngsoon Woo, Han Min 2024-01-20T05:03:59Z 2024-01-20T05:03:59Z 2021-09-05 2016-01 1475-2859 https://pubs.kist.re.kr/handle/201004/124536 Background: An efficient microbial cell factory requires a microorganism that can utilize a broad range of substrates to economically produce value-added chemicals and fuels. The industrially important bacterium Corynebacterium glutamicum has been studied to broaden substrate utilizations for lignocellulose-derived sugars. However, C. glutamicum ATCC 13032 is incapable of PTS-dependent utilization of cellobiose because it has missing genes annotated to beta-glucosidases (bG) and cellobiose-specific PTS permease. Results: We have engineered and evolved a cellobiose-negative and xylose-negative C. glutamicum that utilizes cellobiose as sole carbon and co-ferments cellobiose and xylose. NGS-genomic and DNA microarray-transcriptomic analysis revealed the multiple genetic mutations for the evolved cellobiose-utilizing strains. As a result, a consortium of mutated transporters and metabolic and auxiliary proteins was responsible for the efficient cellobiose uptake. Evolved and engineered strains expressing an intracellular bG showed a better rate of growth rate on cellobiose as sole carbon source than did other bG-secreting or bG-displaying C. glutamicum strains under aerobic culture. Our strain was also capable of co-fermenting cellobiose and xylose without a biphasic growth, although additional pentose transporter expression did not enhance the xylose uptake rate. We subsequently assessed the strains for simultaneous saccharification and fermentation of cellulosic substrates derived from Canadian Ponderosa Pine. Conclusions: The combinatorial strategies of metabolic engineering and adaptive evolution enabled to construct C. glutamicum strains that were able to co-ferment cellobiose and xylose. This work could be useful in development of recombinant C. glutamicum strains for efficient lignocellulosic-biomass conversion to produce value-added chemicals and fuels. English BioMed Central Adaptive evolution and metabolic engineering of a cellobiose- and xylose-negative Corynebacterium glutamicum that co-utilizes cellobiose and xylose Article 10.1186/s12934-016-0420-z 1 Microbial Cell Factories, v.15 Microbial Cell Factories 15 Y scie scopus 000368482400001 2-s2.0-84960074984 Biotechnology & Applied Microbiology Biotechnology & Applied Microbiology Article PHOSPHOTRANSFERASE SYSTEM GENE-EXPRESSION GLUCOSE GENOME FERMENTATION TRANSPORTER CEREVISIAE LYSINE ACIDS Corynebacterium glutamicum Cellobiose and xylose Cofermentation Intracellular beta-glucosidase Adaptive evolution