Identification of a potent protease-producing bacterial isolate, Bacillus amyloliquefaciens CMB01

Abstract – Identification of a potent strain of protease producing bacteria isolated from an environment of food spoilage was made. This isolate exhibited greater activity of extracellular protease compared with the patent strains of protease producer, such as Bacillus subtilis KCTC 1028 ( = ATCC 6051a) and Bacillus licheniformis KCTC 3049 (= ATCC 21424). The newly isolated bacterial strain CMB01 was Gram positive, aerobic endospore-forming rod. It was a mesophilic (optimal growth at 40 oC) and slightly alka-lophilic (optimal growth at pH 8) bacterium. Morphological, biochemical and physio-logical characteristics of the isolate actually suggested it as Bacillus species. The main menaquinone that occurred in this strain was MK-7. On the basis of chemotaxonomic data including cellular fatty acid profile, base sequences of 16S rDNA and gyrA genes, the bacterial isolate was identified as Bacillus amyloliquefaciens. The CMB01 extracel-lular protease seemed to an alkaline protease and a member of serine-proteases. Key words: bacterial identification, Bacillus sp., fatty acid profile, 16S rDNA sequence, gyrA sequence, serine-protease.