Title Isolation and Characterization of a Marine Algicidal Bacterium against the Harmful Raphidophyceae Chattonella marina
Author Yun Sook Kim1, Dae-Sung Lee1, Seong-Yun Jeong2, Won Jae Lee1, and Myung-Suk Lee1*
Address 1Department of Microbiology, Pukyong National University, Busan 608-737, Republic of Korea, 2Korea Bio-IT Foundry Center, Pusan National University, Busan 609-735, Republic of Korea
Bibliography Journal of Microbiology, 47(1),9-18, 2009,
DOI
Key Words Chattonella marina, algicidal bacteria, algicidal activity, algicide, Bacillus, harmful algae blooms (HABs)
Abstract A bacterial strain named AB-4 showing algicidal activity against Chattonella marina was isolated from coastal water of Uljin, Republic of Korea. The isolated strain was identified as Bacillus sp. by culture morphology, biochemical reactions, and homology research based on 16S rDNA. The bacterial culture led to the lysis of algal cells, suggesting that the isolated strain produced a latent algal-lytic compound. Amongst changes in algicidal activity by different culture filtrate volumes, the 10% (100 ?/ml) concentration showed the biggest change in algicidal activity; there, estimated algicidal activity was 95%. The swimming movements of Chattonella marina cells were inhibited because of treatment of the bacterial culture; subsequently, Chattonella marina cells became swollen and rounded. With longer exposure time, algal cells were disrupted and cellular components lost their integrity and decomposed. The released algicide(s) were heat-tolerant and stable in pH variations, except pH 3, 4, and 5. Culture filtrate of Bacillus sp. AB-4 was toxic against harmful algae bloom (HAB) species and nontoxic against livefood organisms. Bacillus sp. AB-4 showed comparatively strong activity against Akashiwo sanguinea, Fibriocapsa japonica, Heterosigma akashiwo, and Scrippsiella trochoidea. These results suggest that the algicidal activity of Bacillus sp. AB-4 is potentially useful for controlling outbreaks of Chattonella marina.