一株芽孢杆菌对球形棕囊藻的溶藻效果

Algae-lytic effect of a Bacillus sp. on Phaeocystis globosa

从珠海香洲码头赤潮海水中分离得到一株芽孢杆菌B1,考察了细菌不同生长期及添加比对球形棕囊藻生长的影响,探讨了藻密度、温度、光照、盐度、藻培养基中N和P含量对溶藻效果的影响.结果表明:稳定期的细菌溶藻效果较好,藻去除率达93.9%,分析球形棕囊藻干重的变化发现,随着球形棕囊藻细胞密度减少,藻干质量减小;细菌的最佳添加体积比为1%,调整期的球形棕囊藻易被细菌去除;温度对溶藻作用有影响,30℃时细菌溶藻作用极显著,去除率达到96.1%,利用HLPC分析溶藻过程球形棕囊藻色素变化,得出的结论与通过丙酮法测叶绿素a含量的结果相近;全黑暗时有利于细菌溶藻,溶藻作用在盐度为35‰时优于其他盐度,藻培养基中N和P的浓度降低时能促进B1菌的溶藻作用.

A bacillus strain named B1 was isolated from red tide water in Xiangzhou shipside of Zhu- hai. The influence of different growth phases and bacterium concentrations on the algae-lytic effects was examined. The effects of algae cell density, temperature, illumination, salinity and the concentrations of N and P on the lytic efficiency were also investigated. The results showed that B1 in stationary growth phase showed the best algae-lytic performance and the removal rate could reach 93.9%. The algal dry weight reduced with the decrease in the algal density. Phaeocystis globosa was largely removed by addi- tion of 1% B1. The removal rate of algae was influenced by the growth phases of the algae, which was the highest in primary growth stage/ B1 showed better algae-lysing ability at 30 ~C, with the removal rate reaching 96. 1%. Cytoehrome variation was analyzed by HPLC, and the result was similar as the acetone method by measuring the content of chlorophyll a. The algicidal activity was significantly enhanced under total dark condition. The algae-lytic effect under the salinity of 35% was better than those under other sa- linity conditions. Reducing the content of N and P could promote the algicidal activity of B1.