The amounts of pentanoate and heptanoate
produced here by combining enzymes for acyl-CoA condensation
with the B12-dependent pathway of propionyl-CoA
formation were 0.201±0.01 and 0.008 g l21, respectively. In
prior studies that produced propionyl-CoA via threonine, the
combined amounts of C5 compounds (pentanoate and
pentanol) produced from glucose or glycerol were about
0.03 or 0.2 g l21, respectively. To our knowledge, heptanoate
has not been previously produced in E. coli by fermentation.
Thus, the approach reported here appears to be a promising
basis for further development of odd-chain FA production
not only by fermentation, but also by premature termination
of lipid biosynthesis or reverse b-oxidation.