Fu Lijun, Li Dong, Wu Chengji, Zheng Tianling
Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China.
Wei Sheng Wu Xue Bao. 2012 Jun 4;52(6):784-90.
We studied the algicidal mechanism of extracellular substances of algicidal bacteria strain BS03 (Microbulbifer sp.) on photosynthetic characteristics, antioxident enzyme system and cysteine-dependent aspartate specific protease-3 (Caspase-3) of Alexandrium tamarense.
We tested photosynthetic pigments, chlorophyll fluorescence efficiency, antioxidant systems and caspase-3 activity in the algae cells treated with 0.5%, 1.0% , 1.5% and 2.0% BS03 cell-free filtrate after 12, 24, 36 and 48 h.
(1) The chlorophyll-a and chlorophyll fluorescence efficiency Fv/Fm decreased with the increase of BS03 cell-free filtrate and treatment time. Carotenoids contents of A. tamarense cells treated with low BS03 (0.5% and 1.0%) cell-free filtrate were higher than the control. (2) Antioxident enzyme activities varied as treatment time and concentration. Malodialdehyde (MDA) contents increased significantly with BS03 cell-free filtrate treatment. (3) Caspase-3 protease activities of algal cells increased by BS03 cell-free filtrate.
BS03 inhibited the photosynthesis whereas enhanced the lipid peroxidation of the cellular membrane of Alexandrium tamarense, indicating its algicidal activity.
研究溶藻细菌菌株BS03（微小杆菌属）胞外物质对塔玛亚历山大藻光合特性、抗氧化酶系统及半胱氨酸天冬氨酸特异性蛋白酶-3（Caspase-3）的溶藻机制。
用0.5%、1.0%、1.5%和2.0%的BS03无细胞滤液处理藻细胞12、24、36和48小时后，检测藻细胞中的光合色素、叶绿素荧光效率、抗氧化系统和Caspase-3活性。
（1）叶绿素a和叶绿素荧光效率Fv/Fm随BS03无细胞滤液浓度和处理时间的增加而降低。用低浓度（0.5%和1.0%）BS03无细胞滤液处理的塔玛亚历山大藻细胞中类胡萝卜素含量高于对照组。（2）抗氧化酶活性随处理时间和浓度而变化。丙二醛（MDA）含量随BS03无细胞滤液处理显著增加。（3）BS03无细胞滤液使藻细胞的Caspase-3蛋白酶活性增加。
BS03抑制了塔玛亚历山大藻的光合作用，增强了其细胞膜的脂质过氧化，表明其具有溶藻活性。
