Isolation,identification and characterization of algicidal bacterium BS03 against Alexandrium tamarense

作者简介: 李东( 1986—) ，男，E-mail: lidongbox2006@163． com; * 通讯作者( 责任作者) ，E-mail: wshwzh@ xmu． edu． cn Biography: LI Dong( 1986—) ，male，E-mail: lidongbox2006@163． com; * Corresponding author，E-mail: wshwzh@ xmu． edu． cn[中文文摘]从福建漳江口红树林区筛选出一株对产贝毒赤潮原因藻——塔玛亚历山大藻(Alexandrium tamatense)具有强溶藻能力的细菌,命名为BS03,通过生理生化及16S rDNA序列分析对该菌株进行鉴定,并探讨了菌株BS03对塔玛亚历山大藻的溶藻特性和溶藻代谢产物的初步性质.结果发现,菌株BS03属于微泡菌属(Microbulbifer sp.)相似性达99%;对塔玛亚历山大藻的杀藻效果具有一定浓度效应,在一定浓度范围内处理浓度越高,溶藻效果越好;菌株BS03对处于不同生长时期的塔玛亚历山大藻都表现出较好的杀藻效果,其中对处于延滞期的塔玛亚历山大藻表现出最佳的杀藻效果,处理96h后,抑藻率达98.17%;不同生长期菌株对塔玛亚历山大藻溶藻作用无明显差异;菌株BS03通过间接作用方式溶藻,所分泌的胞外活性物质的分子量小于1kDa,耐酸碱、具热稳定性,推测为非蛋白质、非核酸和非多糖类物质. [英文文摘] A bacterial strain，BS03，exhibiting strongest activity against the toxic dinoflagellate，Alexandrium tamatense，was isolated from the Zhangjiang Estuary Mangrove National Natural Reserve，China． Based on 16S rRNA gene sequences and biochemical and morphological characteristics，the strain BS03 was determined to be Microbulbifer sp． on the basis of 99． 0% similarity with reference strain sequences from the NCBI． The growth of A． tamatense was strongly suppressed by BS03 in all growth phases． With the strongest algicidal activity noted against harmful algae in the lag stage，the removal rate of A． tamatense reached 98.17% after 96 h． In addition，the initial concentration of the bacterial culture strongly affected the algicidal ability． The higher concentration of the bacterial culture was，the stronger algicidal activity to the A.tamatense.Furthermore，BS03 indirectly attacked A． tamatense by algicidal substances． The molecular weight of algicidal compounds were less than 1 kDa，and heat tolerant and stable in acidic and alkaline conditions． According to our results，we speculated the algicidal compounds could not be proteinaceous，nucleate and polysaccharide． These findings indicated that strain BS03 could be a potential bio － agent for future use in controlling harmful algal blooms．国家自然科学基金重点项目、面上项目(No.40930847,31070442);福建省自然科学基金(No.2010J01150);海洋公益性行业科研专项经费资助(No.201305016,201305041,201305022

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