1.1.1.48 - 1.1.1.48 beta-galactosidase-galactose dehydrogenase fusion enzymes, expressed in Escherichia coli 1.1.1.48 expressed in Escherichia coli BL21(DE3) cells 1.1.1.48 expressed in Escherichia coli, Escherichia coli beta-galactosidase promotor 1.1.1.48 expressed in Escherichia coli, point mutations in natural promotor increase expression