Authors: Zhihui Zhou Chen Wang Hongtao Xu Zhongjun Chen Heng Cai
Publish Date: 2015/05/08
Volume: 42, Issue: 7, Pages: 1073-1082
Abstract
Succinic acid synthesized from glucose shows potential as a biobased platform chemical However the need for a high glucose concentration and the accompanying low yields limit its industrial applications Despite efficient glucose uptake by the phosphotransferase system PTS 1 mol of phosphoenolpyruvate is required for each mole of internalized glucose Therefore a PTSdefective Corynebacterium glutamicum mutant was constructed to increase phosphoenolpyruvate availability for succinic acid synthesis resulting in a lower glucose utilization rate and slower growth The transcriptional regulator iolR was also deleted to enable the PTSdefective mutant to utilize glucose via iolTmediated glucose transport Deletion of iolR and overexpression of iolT1 and ppgk polyphosphate glucokinase in the PTSdeficient C glutamicum strain completely restored glucose utilization increasing production by 116 and yield by 324 compared with the control This study revealed for the first time that iolR represses the expression of the two glucokinase genes glk and ppgk
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