(623bs) Characterization of Short Chain Alcohol Dehydrogenases From Lactobacillus Brevis

The substrate specificity of several previously uncharacterized short chain alcohol dehydrogenases from Lactobacillus brevis was explored. Six putative enzymes were cloned and overexpressed in E. coli. Protein BLAST (Basic Local Alignment Search Tool) analysis was done to determine possible substrates for which each protein may possess activity. The catalytic activity of LVIS_0108 on D-gluconate was confirmed and its dual cofactor (NAD⁺ and NADP⁺) specificity was investigated. In addition, the gene LVIS_0347, identified by Hummel et al. as the (R)-stereospecific alcohol dehydrogenase (RADH), was found to possess broad substrate activity on several short chain aldehydes and ketones, previously uncharacterized to perform such activity. Catalytically efficient, broad substrate alcohol dehydrogenases are especially useful for biofuel synthesis pathways. To demonstrate its relevance to the biofuels industry and its utility as a broad substrate alcohol dehydrogenase, a detailed catalytic characterization was performed to further investigate the activity of LVIS_0347. The remaining four putative enzymes remain under investigation as to their substrate specificity and functionality in L. brevis.