Isolation and characterization of Bdellovibrio strains from the ocean

Abstract:

Abstract:[ Objective] To isolate and identify the new Bdellovibrio strains from the sea mud of Shenzhen bay and to preliminarily study their biological characteristics. [Methods] We isolated Bdellovibrio strains by DNB(dilute nutrient broth) double-layer plate method. Their 16S rDNAs were sequenced and their morphologies were examined under electron microscope. We identified these strains according to the ninth edition of Bergey’s manual of determinative bacteriology. We also studied their biological characteristics through physiological tests. [Results] We isolated 2 strains of Bdellovibrio sp. (5#-12 and 5#-sh06) from sea mud of Shenzhen bay. Both strains grew between 20℃ and 35℃, with 25℃ and 30℃ as optimal temperature for 5#-12 and 5#-sh06, respectively. They grew between pH 6.1 and 8.6, and the opti℃mal pH for both was 7.2. Lysis experiments on 58 strains of pathogens were conducted and the results showed that 5#-12 and 5#-sh06 lysed 46 and 48 strains, corresponding to 79.3% and 82.8% of lysis abilities. Taken both two Bdellovibrio strains together, they lysed 96.6% (56 strains) of tested pathogens and 100% of tested vibrios (39 strains). [Conclusion] The results demonstrated that Bdellovibrio have potential and significant application prospect for elimination of pathogens.