Co-utilization of glucose and xylose by evolved Thermus thermophilus LC113 strain elucidated by (13)C metabolic flux analysis and whole genome sequencing.

摘要: We evolved Thermus thermophilus to efficiently co-utilize glucose and xylose, the two most abundant sugars in lignocellulosic biomass, at high temperatures without carbon catabolite repression. To generate strain, T. HB8 was first on improve its growth characteristics, followed by evolution xylose. The resulting LC113, characterized studies, whole genome sequencing, (13)C-metabolic flux analysis ((13)C-MFA) with [1,6-(13)C]glucose, [5-(13)C]xylose, [1,6-(13)C]glucose+[5-(13)C]xylose as isotopic tracers. Compared starting strain had an increased rate (~2-fold), biomass yield, tolerance up 90°C, gained ability grow xylose minimal medium. At optimal temperature of 81°C, maximum 0.44 0.46h(-1), respectively. In medium containing co-utilized sugars. (13)C-MFA results provided insights into metabolism LC113 that allows efficient co-utilization Specifically, revealed metabolic fluxes upper part adjust flexibly sugar availability, while lower remain relatively constant. Whole sequence large structural changes can help explain physiology strain: a duplication chromosome region contains many transporters, 5x multiplication pVV8 plasmid isomerase xylulokinase genes, enzymes catabolism. Taken together, complementary strain.