Su Jian-qiang, Yu Zhi-ming, Tian Yun, Song Xiu-xian, Hong Hua-sheng, Zheng Tian-ling
School of Life Sciences, Xiamen University, Xiamen 361005, China.
J Environ Sci (China). 2005;17(6):1047-50.
The relationship between Alexandrium tamarense (Lebour) Balech, one of red-tide alga, and two strains of marine bacteria, Bacillius megaterium (S7) and B. halmapulus (S10) isolated from Xiamen Western Sea, was investigated by evaluating the growth state of A. tamarense and the variation of beta-glucosidase activity in co-culture system. The results showed the growth and multiplication of the alga were related with the concentration, genus speciality of the bacteria, and growth stage of the alga itself. The growth of A. tamarense was obviously inhibited by S7 and S10 at high concentration. Either inhibition or promotion contributed much more clearly in earlier than in later stage of the growth of the alga. Furthermore, there was a roughly similar variation trend of the activity of extra-cellular enzyme, beta-glucosidase, in the water of the separately co-cultured bacteria S7 and S10 with the alga. The beta-glucosidase activity (beta-GlcA) rapidly increased during the later algal growth accompanying the increase of the lysis of the alga cells. The obvious inhibition of A. tamarense by marine bacteria at high concentration and evident increase of beta-GlcA in co-colture system would help us in better understanding the relationship between red-tide alga and bacteria, and also enlightenedus the possible use of bacteria in the bio-control of red-tide.
通过评估塔玛亚历山大藻（Lebour）Balech（一种赤潮藻类）的生长状态以及共培养系统中β-葡萄糖苷酶活性的变化，研究了该赤潮藻与从厦门西海域分离出的两株海洋细菌巨大芽孢杆菌（S7）和盐沼芽孢杆菌（S10）之间的关系。结果表明，藻类的生长和繁殖与细菌的浓度、属的特异性以及藻类自身的生长阶段有关。在高浓度下，S7和S10对塔玛亚历山大藻的生长有明显抑制作用。无论是抑制还是促进作用，在藻类生长的早期阶段都比后期更为明显。此外，在分别与藻类共培养的细菌S7和S10的水体中，胞外酶β-葡萄糖苷酶的活性变化趋势大致相似。随着藻类细胞裂解的增加，β-葡萄糖苷酶活性（β-GlcA）在藻类生长后期迅速增加。海洋细菌在高浓度下对塔玛亚历山大藻的明显抑制以及共培养系统中β-GlcA的明显增加，将有助于我们更好地理解赤潮藻与细菌之间的关系，也为利用细菌进行赤潮生物防治提供了启示。
