Zymomonas mobilis IFO 13 756 could take up galactose and metabolize it so that galactonic acid accumulated in the culture fluid. The oxidation of galactose was catalysed by a membrane-associated enzyme, which could be solubilized with a mixture of 1% Triton X-100 and 1 M: KC1. The strain also accumulated galactitol as a minor metabolite. To confer the ability to utilize galactose on Z. mobilis, a Gal(+) recombinant plasmid, pZG13, was constructed by the insertion of the galETK genes of Escherichia coli immediately downstream of the Z. mobilis promoter gene in pZA22, the plasmid introduced into a Zymomonas strain. Uridine diphospho-glucose 4-epimerase coded in the galE gene was expressed in Z. mobilis carrying pTG13. The recombinant strain could produce a small amount of ethanol from galactose.