First report on molecular characterization of novel betaine aldehyde dehydrogenase from the halotolerant eubacteria, Bacillus halodurans

Betaine aldehyde dehydrogenase (BADH) is an effective compatible solute, which maintains fluidity of membranes and protects the biological structure of the organisms under stress. Betaine aldehyde dehydrogenase catalyses the last step in the biosynthetic pathway that leads to glycine betaine. In this study, betaine aldehyde dehydrogenase (BADH1) from the halotolerant Bacillus halodurans SMBPL06 was heterologously expressed in Escherichia coli M15 (pREP4). The recombinant enzyme was purified by column chromatography using DEAE sepharose. The purified enzyme revealed a five-fold increase in the activity with choline as substrate and phenazine methosulfate as electron acceptor, compared to the control strain. The betaine aldehyde dehydrogenase gene sequences reported in this study contains several base substitutions with that of reported sequences in GenBank, resulting in the altered amino acid sequences of the translated proteins.