Fig. 6
Gene overexpression simulation of the designed knockout mutants by flux balance analysis. The knockout mutants designed for high isobutanol/hexadecanol yields (Fig. 5) were analyzed for the gene overexpression effect to identify target gene overexpression for improving productivity of isobutanol (a) and hexadecanol (b). Target genes for overexpression is determined based on maximal flux correlation (FC), defined as change in flux towards product synthesis (qP) relative to change in reaction flux via gene overexpression simulation (Ri). The maximum slope between qP and Ri in FC means increasing reaction flux (Ri) via gene overexpression would lead to the most enhanced rate of product synthesis (qP). Target genes for overexpression (indicated by red arrow) would reshape phenotypic space by pulling towards high productivity of product synthesis