Characterization of sugar mixtures utilization by an Escherichia coli mutant devoid of the phosphotransferase system.

摘要: Due to catabolite repression in microorganisms, sugar mixtures cannot be metabolized a rapid and efficient manner. Therefore, the development of mutant strains that avoid this regulatory system is special interest fermentation processes. In present study, utilization by an Escherichia coli strain devoid phosphotransferase (PTS) was characterized. This can transport glucose (PTS– Glucose+ phenotype) non-PTS mechanism as rapidly its wild-type parental strain. cultures grown minimal medium supplemented with glucose-xylose or glucose-arabinose mixtures, repressed arabinose- xylose-utilization However, under same culture conditions PTS– mutant, arabinose were co-metabolized, but still exerted partial repressive effect on xylose consumption. growing triple mixture glucose-arabinose-xylose, sequentially utilized glucose, finally, xylose. contrast, co-metabolized arabinose, whereas after depletion. As result co-metabolism, consumed total amount sugars contained 16% faster than [14C]-Xylose uptake experiments showed strain, galactose permease increases capacity observed depends presence intracellular glucose.