Fermentation of sweet whey by recombinant "Escherichia coli" KO11

The production of ethanol from sweet whey using the recombinant "Escherichia coli" KO11, in batch fermentation, was tested. The maximum ethanol yield was reached after 96h, representing only 38(per cent) of the theoretical yield. The supplementation of whey with components of LB broth increased the maximum yield to 96(per cent) in 72h. The addition of 0.5(per cent) yeast extract to whey resulted in maximum yield of 47(per cent) at 36h and it increased to over 100(per cent) when yeast extract and trace metals solution (Fe++, Mn++ and Zn++) were added.