0 mutations pentose phosphate pathway

The pathway borrows heavily from the nonoxidative branch of the pentose phosphate pathway and from gluconeogenesis. Without doubt, the pathways yield sugars as well as NADPH for reductive biosynthesis. Thus, only a few new enzymes would have to evolve through mutations to enable the complete Calvin cycle to function. 

Further improvement in production performance was achieved with a strain containing a tkt mutant allele (instead of the wild type) with drastically reduced enzymatic transketolase activity [180]. Transketolase is a key enzyme in the pentose phosphate pathway delivering ribulose-5-P and ribose-5-P, which are important building blocks for riboflavin biosynthesis. Presumably, the mutation impedes drainage of the pentose phosphate pathway intermediates back toward... 

Normally, glucoso-6-phosphate is used in glycolysis and in the pentose cycle. The mutation in the Pgd gene blocks the oxidation pathway in pentose biosynthesis and, hence, 6-phosphogluconate is accumulated. This situation is lethal for an organism. If there is another termination of the pentose cycle by a mutation in gene... 

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