Isolation and Characterization of an L-Amino Acid Oxidase-Producing Marine Bacterium

One marine bacterial strain, R3, has been newly isolated from the intertidal zone of Dinghai sea area. Measurements of a-keto acids and H2O2 existing in fermentation supernatant were carried out to show that R3 can produce L-amino acid oxidase (LAAO) with a broad substrate specificity. Physiological and biochemical analysis showed that it can grow great at the conditions with sodium chloride concentration of 1.5% 3%, temperature of 15 ̊C 35 ̊C and pH of 6 7. In addition, molecular identification of 16S rDNA was performed to show that R3 was proximal to Pseudoalteromonas spp. with the highest identity of 98.5% to Pseudoalteromonas rubra. Therefore, it was designated as Pseudoalteromonas sp. R3. Further studies are required to arrive at a better understanding of this LAAO and secure an application.