LYSIS OF VIBRIOS BY BDELLOVIBRIO‐AND‐LIKE ORGANISMS (BALOs) ISOLATED FROM MARINE ENVIRONMENT

ABSTRACT Four marine Bdellovibrio ‐and‐like organisms (BALOs), viz. BDW01, BDW02, BDW03 and BDW04, were isolated from the Shenzhen Bay of Guangdong province, China, using Vibrio parahaemolyticus (Vp) strain minus as the host bacterium. They were identified as BALOs by electron microscopy and specific polymerase chain reaction methods. Lysis experiments on 41 potentially pathogenic vibrios showed that individually, BDW01, BDW02, BDW03 and BDW04 lysed 36.6, 39.0, 65.8 and 63.4% vibrios, respectively. In combination, they lysed 87.8% of the vibrios tested. In terms of different vibrio species lysed, four BALOs combined could lyse 81.8% Vibrio alginolyticus (11 strains), 83.3% non‐O1 Vibrio cholerae (6 strains), 88.9% Vibrio fluvialis (9 strains), 100% Vibrio minicus (4 strains) and 88.9% Vp (9 strains). The results of this work clearly demonstrated the potential of BALOs in lysing potentially pathogenic vibrios. PRACTICAL APPLICATIONS Marine Bdellovibrio ‐and‐like organisms (BALOs) have many potential applications, particularly in the seafood processing industry, seafood restaurants' and markets' aquaria as well as in marine aquaculture and in research laboratory where sterilization of live organisms is required. As vibrios, either pathogenic or potentially pathogenic, are ubiquitous in the marine environments, contamination of fish and/or shellfish with vibrios is unavoidable and very common. BALOs can therefore be employed to lyse vibrios in these circumstances via proper means. In our research ( Cai et al . 2006 ), BALOs have successfully been applied to reduce Vibrio parahaemolyticus in oyster‐rearing environments in a laboratory scale. They have also been successfully applied, in place of antibiotics, to eliminate bacteria from some algae. Currently, the applications of BALOs in seafood restaurants' and markets' aquaria are under evaluation.