【作者】 许丽娜；

【导师】 赵以军； 杨季芳；

【作者基本信息】 华中师范大学 ， 水生生物学， 2010， 硕士

【摘要】 本实验以海洋真核藻为材料,从宁波象山港分离得到两株新型的溶藻细菌,分别命名为菌株XD-G和XD-J。菌株XD-G对中肋骨条藻(Skeletonema costatum 1115)的溶藻效果较好,感染1天后,藻细胞基本裂解,叶绿素a减少达66.5%；在透射电子显微镜下观察菌株XD-G感染9小时后的中肋骨条藻(S. costatum 1115)切片,发现藻细胞内有大量细菌出现,由此推测,菌株XD-G是一种寄生溶藻细菌；XD-G菌株不但能裂解中肋骨条藻(S.costatum 1115)和热带骨条藻(Skeletonema troicum),而且对赤潮异弯藻Heterosigma akashiwo)也有一定的溶藻效果。国内外还未见有关中肋骨条藻寄生细菌的报道,因此XD-G是一种新发现的寄生溶藻细菌。菌株XD-J对球等鞭金藻(Isochrysis galbana)具有明显的溶藻效果：感染4天后,叶绿素a减少达76.4%；藻裂解液经孔径为0.22μm的针头式过滤器过滤,滤液对球等鞭金藻(I. galbana)无溶藻效果,透射电子显微镜切片观察,藻细胞内未见细菌,因此,初步推测菌株XD-J为直接接触溶藻方式或与藻细胞竞争营养物质溶藻；XD-J菌株的耐热性较差,最高耐受温度40-50℃间；在测试的海洋微藻中,XD-J仅对球等鞭金藻(I. galbana)有溶藻效果。更多还原

【Abstract】 Using marine eukaryotic algae as the experimental material, two novel algicidal bacteria named XD-G and XD-J were isolated from the water of XiangShan Bay in NingBo.The algicidal effect of the bacteria XD-G against S. costatum 1115 was significant: almost all of the algal cells were lysed in 24 hours, and the concentration of Chl.a was reduced by 66.5% then. By electron microscope observation, a large number of the bacteria could be observed in S. costatum cells after 9 hours’ infection, which means that the bacterium XD-G is a kind of parasitic bacterium. Furthermore, the bacteria XD-G could not only lyse S. costatum 1115 and Skeletonema troicum, but also removed Heterosigma akashiwo. There was no report about the parasitic bacteria of S. costatum, so the bacterium XD-G is a novel parasitic algicidal bacterium.The algicidal effect of the bacteria XD-J against Isochrysis galbana was significant: the concentration of Chl.a was reduced by 76.4% after 4 days’ infection. The culture of bacteria XD-J filtered by the membrane filter of 0.22μm, and its filtrate was added into the culture of I. galbana, however, there was no algicidal phenomenon. By electron microscope observation, there were no bacteria in I. galbana Cells, which means that the bacterium XD-J is a kind of bacterium which can lyse I. galbana for the direct contact with the algal cells. But it did not eliminate the possibility that the bacteria XD-J competed with algal cells for the nutrients. The bacterium XD-J has poor heat-tolerant, and the maximum tolerable temperature is between 40℃and 50℃. The bacteria XD-J only could lyse I. galbana.更多还原