Analysis of attached bacteria on algal cells by fluorescence in situ hybridization with oligonucleotide prove

蓝藻对藻华的影响研究很多。然而，我们对藻华发生的机理还不十分了解，也无法预测藻华何时发生。我认为附着在藻细胞上的细菌对控制藻的生长和藻细胞的分解起着重要的作用。然而，关于附着在藻细胞上的细菌与藻类之间关系的研究却很少。在本研究中，我着重阐明了藻细胞上的细菌种类及其对藻华的影响。首先，采用16S rDNA方法研究了霞aura湖浮游细菌的季节和地理动态。pcr -变性梯度凝胶电泳（PCR-DGGE）结果显示，不同采样时间间细菌群落变化显著，而不同采样地点间细菌群落变化不明显。接下来，我用PCR-DGGE等方法比较了预滤液去除悬浮物（包括藻类细胞）和湖水中细菌的多样性。预滤湖水中存在较多条带的趋势，而湖水中则有少量高密度条带的趋势。这一结果被认为是某些细菌种类在悬浮物上占优势。放线菌属的一种细菌在总湖水和预滤水中经常占优势。然后从优势放线菌种的16S rDNA序列中提取引物，分析细菌附着藻细胞。用该引物与27F通用引物对从霞浦湖水体中选择的几个菌落进行PCR。这组引物找到了2种细菌，我测定了这2种细菌的16S-rDNA序列。然而，不幸的是，这些细菌属于变形菌门Y分支。现在，我再一次确定了其他引物序列。在本研究中，我用多聚甲醛和荧光染料测定了FISH的细菌固定条件。少

There are many researches for algal bloom by Cyanobacteria. However, we have not quite understood the mechanism of algal bloom and we can not predict when algal blooms happen, yet. I suppose that attached bacteria on algal cells play an important role on control of algal growth and decomposition of algal cells. However, there are few studies about the relationship between attached bacteria on algal cells and algae. In this study, I focused to elucidate the bacterial species on the algal cells, and their effects to the algal bloom.First, I studied seasonal and geographical dynamics of bacterioplankton in Lake Kasumigaura by 16S rDNA methods. The results of PCR-denaturing gradient gel electrophoresis (PCR-DGGE) showed that changes in the bacterial community were prominent between different sampling times, but not between different sampling sites. Next, I compared diversity of bacteria in lake water and water removed suspended solids (include algal cells) by pre-filtrate using PCR-DGGE me … More thods. There is tendency that many bands are in pre-filtrated lake water, on the other hand small number of high density bands are in lake water. This result was regarded that certain bacterial species are predominant on suspended solids. One species bacteria belong to Actinobacteria came frequently predominant in total lake water and pre-filtrated water.Then I made a primer from 16S rDNA sequence of the Actinobacteria species came predominant to analyze the bacteria attached algal cells. PCR was carried out by using primer set of this primer and 27F universal primer on several bacterial colonies that were selected from Kasumigaura lake water. This primer set found 2 species bacteria and I determined 16S-rDNA sequence of this 2 species. However, unfortunately theses bacterial species belong to Proteobacteria Y Subdivision. Now, I am determining several other primer sequences, once again. And, I determined bacterial fixing condition by paraformaldehyde and fluorescent dye for FISH, in this study. Less