SCREENING,IDENTIFICATION,AND ANTIMICROBIAL SPECTRUM OF A MARINE BIOCONTROL BACTERIUM STRAIN LHB02

The bacterium strain LHB02, which exhibited high inhibitory effects against a number of aquatic pathogens, was separated from marine sediments heavily polluted by aquaculture. Using a pair of universal primers, a fragment of LHB02’s 16S rRNA gene was amplified and a 1511bp of its DNA sequence was obtained. Based on its morphological, physiological and biochemical characteristics, LHB02 was identified as Bacillus subtilis. The active substance purified using ammonium sulfate precipitation and subsequent dialysis was identified as a crude antibacterial protein. In the following antimicrobial test, LHB02 showed strong antagonistic effects against three types of vibrios: Vibrio harveyi, V. alginolyticus and V. anguillarum.