细菌B1胞外活性物质对球形棕囊藻的溶藻机制初探

Preliminary investigation on algicidal mechanism of extracellular active substances from an algae-lysing bacterium B1 to Phaeocystis globosa

为探讨溶藻细菌B1对球形棕囊藻的溶藻作用机理及起作用的胞外活性物质的类别,研究了从珠海香洲码头赤潮海水中分离获得的溶藻细菌B1的无菌滤液对球形棕囊藻生长过程中的叶绿素a含量、丙二醛含量(MDA)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的影响,并对溶藻细菌B1分泌的胞外活性物质进行了初步分析.当100mL藻液中加入1mL的无菌滤液,除藻率达到了83%.B1无菌滤液使藻中丙二醛的含量显著上升,48h达到最大值153%,球形棕囊藻的SOD、CAT活性在处理开始后保持下降趋势,分别在96h、48h达到最低值27%、33%.研究表明B1无菌滤液(不大于1mL)对棕囊藻的溶藻效果与加入的量成正比,且主要通过降低机体中保护酶的活性和加剧膜脂质过氧化的程度等来抑制球形棕囊藻的生长;细菌B1分泌的胞外活性物质中可能含有芳香醛类且包括载有磷基团的有机物,但不含蛋白质.

In order to further investigate the algae-lytic effect of B1 isolated from red tide water in Xiangzhou Shipside of Zhuhai, the algae-lytic influences of different contents of B1 bacteria-free filtrate on the content of chlorophyll a and malondialdehyde （MDA） , superoxide dismutase （SOD） and eatalase （CAT） activity were studied in the growth of Phaeocystis globosa, and the B1 extracellular active substances were analyzed preliminarily. When more than 1 mL bacteria-free filtrate was added into 100 mL Phaeocystis globosa, the effect of algae-lying was the best without extra-interference and the removal rate was 83%. MDA content also increased and reached the maximum 153% after 48 hour. The activity of SOD and CAT always kept decreasing, and reached the minimum of 27% and 33% after 96 and 48 hour, respectively. The results showed the content of bacteria-free filtrate was proportional to the effect of algae-lying in a certain range. Algae-lysis of B1 was mainly attributed to the decreased activity of SOD, CAT and peroxidation enhancement of the cellular membrane which resulted in the growth inhibition of Phaeocystis globosa. The algae-lysing components probably included aromatic aldehyde and phosphorus groups, but not protein.