Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6494412 | Metabolic Engineering | 2015 | 8 Pages |
Abstract
After glucose, xylose is the most abundant sugar in lignocellulosic carbon sources. However, wild-type Escherichia coli is unable to simultaneously utilize both sugars due to carbon catabolite repression (CCR). In this paper, we describe GX50, an engineered strain capable of utilizing glucose and xylose simultaneously. This strain was obtained by evolving a mutant from which araC has been deleted, and in which genes required for pentose metabolism are constitutively expressed. The strain acquired four additional mutations during adaptive evolution, including intergenic mutations in the 5â²-flanking region of xylA and pyrE, and missense mutations in araE (S91I) and ybjG (D99G). In contrast to wild type E. coli, GX50 rapidly converts xylose to xylitol even if glucose is available. Notably, the strain grows well when cultured on glucose, unlike some well-known CCR-insensitive mutants defective in the glucose phosphotransferase system. Our work will advance efforts to design a metabolically efficient platform strain for potential use in producing chemicals from lignocellulose.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Bioengineering
Authors
Suk Min Kim, Bae Young Choi, Young Shin Ryu, Sung Hun Jung, Jung Min Park, Goo-Hee Kim, Sung Kuk Lee,