| 摘要: |
| 近年来，有害藻华频繁发生给海洋生态系统甚至人类健康带来严重影响。伊姆裸甲藻（Gymnodinium impudicum）是一种典型有害藻华原因种，开展其溶藻菌筛选工作，将有利于该种藻华的防控研究。本研究从伊姆裸甲藻藻华发生海域，分离一株针对藻华原因种的溶藻菌LD-B3，16S rDNA序列分析表明，该菌株属于假交替单胞菌属（Pseudoalteromonas）。菌藻共培养结果显示，2.0%终浓度LD-B3菌液添加72 h后，伊姆裸甲藻溶藻率达81.06%，且溶藻效应呈现浓度和时间依赖性。显微观察和生理参数测定结果表明，菌株LD-B3可导致伊姆裸甲藻细胞链断裂，最大光合效率（Fv/Fm）下降。溶藻方式研究发现，菌株LD-B3主要通过分泌胞外物质实现溶藻，且这类物质对温度较为敏感，初步推断其可能为蛋白类物质。本研究结果表明菌株LD-B3在伊姆裸甲藻溶藻剂开发方面有一定应用前景。 |
| 关键词: 海洋生物学 有害藻华 伊姆裸甲藻 溶藻菌 假交替单胞菌 |
| DOI：10.3969/J.ISSN.2095-4972.20221018003 |
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| 基金项目:国家重点研发计划(2020YFD0900203)；江苏省农业科技自主创新项目\[CX(22)2032\]；国家自然科学基金青年基金(42006135)；江苏高校优势学科建设工程项目 |
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| Isolation and characterization of an algicidal bacterium LD-B3 against the bloom-forming algaeGymnodinium impudicum |
| LI Junjia,CHEN Lei,WANG Junyue,CAI Yuefeng,SHEN Xin,JI Nanjing |
| (Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China;CoInnovation Center of Jiangsu Marine Bioindustry Technology, Jiangsu Ocean University, Lianyungang 222005, China;Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China) |
| Abstract: |
| In recent years, harmful algal blooms (HABs) have caused significant damage to ecosystems and public health around the world,and the bloom occurrences are increasing in frequency and intensity. The dinoflagellate Gymnodinium impudicum is a typical HAB species, isolation and characterization of algicidal bacteria will be beneficial to control its blooms. In this study, isolation of an algicidal bacterium LD-B3 against G. impudicum was performed. 16S rDNA analysis showed that LD-B3 belonged to genus Pseudoalteromonas. After 72 h of LD-B3 bacterium culture addition, the algicidal rate reached up to 81.06% after adding with 2.0% at final concentration. As result, algicidal activity was shown both concentration and time dependent. The results of microscopic observation and measurement of physiological parameters showed that strain LD-B3 could lead to the breakage of Gv. impudicum cell chain and the decrease of Fv/Fm. Moreover, our results indicated that strain LD-B3’s extracellular compounds were involved in algicidal activity, and these substances, probably a protein compound, were sensitive to temperature. Generally, these findings indicated that the strain LD-B3 is a potential source of bacterial to mitigate G. impudicum blooms. |
| Key words: marine biology harmful algae bloom Gymnodinium impudicum algicidal bacterium Pseudoalteromonas |
