| Title | Isolation of an algicide from a marine bacterium and its effects against the toxic dinoflagellate Alexandrium catenella and other harmful algal bloom species |
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| Author | Yun Sook Kim1, Hong-Joo Son2, and Seong-Yun Jeong3* |
| Address | 1Marine Bioprocess Co. LTD., Busan 619-912, Republic of Korea, 2College of Natural Resources and Life Science, Pusan National University, Miryang 627-706, Republic of Korea, 3Department of Biomedical Science, Catholic University of Daegu, Gyengsan 712-702, Republic of Korea |
| Bibliography | Journal of Microbiology, 53(8),511-517, 2015, |
| DOI | 10.1007/s12275-015-5303-1 |
| Key Words | Alexandrium catenella, algicidal activity, algicide, Brachybacterium, harmful algal bloom species, 1-acetyl- β-carboline |
| Abstract | The aim of this study was to isolate and identify bacteria demonstrating an algicidal effect against Alexandrium catenella and to determine the activity and range of any algicide discovered. The morphological and biochemical attributes of an algicidal bacterium, isolate YS-3, and analysis of its 16S rRNA gene sequence revealed it to be a member of the genus Brachybacterium. This organism, designated Brachybacterium sp. YS-3, showed the greatest effect against A. catenella cells of all bacteria isolated, and is assumed to produce secondary metabolites. When 10% solutions of culture filtrates from this strain were applied to A. catenella cultures, over 90% of cells were killed within 9 h. Bioassay-guided isolation of the algicide involved led to the purification and identification of an active compound. Based on physicochemical and spectroscopic data, including nuclear magnetic resonance and mass analyses, this compound was identified as 1-acetyl-β-carboline. This algicide showed significant activity against A. catenella and a wide range of harmful algal bloom (HAB)-forming species. Taken together, our results suggest that Brachybacterium sp. YS-3 and its algicide represent promising candidates for use in HAB control. |