ptac 85 prv480 and dh10b pgs367 prv480 at two different dilution rates is shown in fig8 both strains showed higher glucose uptake rate at the higher dilution rates at a dilution rate of 0 35 hr the control strain dh10b ptac 85 prv480 exhibited a significantly higher uptake rate than dh10b pgs367 prv480 which overexpresses both pank and pdh the specific acetate production rate for dh10b pgs367 prv480 is significantly higher than the control strain at both dilution rates fig9 at the dilution rate of 0 15 hour dh10b pgs367 prv480 displays a 103 increase in acetate production at a dilution rate of 0 35 hour dh10b pgs367 prv480 displays a 53 increase in acetate production these results suggested that higher carbon flux through the a coa node was achieved by co expressing both pank and pdh two recombinant strains were constructed dh10b ptac 85 patca and dh10b pgs367 patca both strains overexpress pantothenate kinase due to which both strains have elevated coa a coa levels when the cell culture medium is supplemented with pantothenate similarly both the strains overexpress alcohol acetyltransferase and therefore can produce isoamyl acetate when isoamyl alcohol is added externally to the cell culture medium however only the strain dh10b pgs367 patca overexpresses pdh thereby enhancing the carbon flux from pyruvate to a coa in this strain the production of isoamyl acetate was studied in both strains to elucidate the effect of this coexpression on isoamyl acetate production no increase in isoamyl acetate production was observed upon overexpression of pyruvate dehydrogenase in addition to pantothenate kinase data not shown the results of isoamyl acetate production can be explained if the competition of acetate production pathway at the a coa node is taken into consideration the enzyme alcohol acetyltransferase aat which condenses isoamyl.