Microbial ecology and environmental monitoring in micro-habitat in streams

溪流微生境的微生物生态学和环境监测

• 批准号: 14340245
• 负责人: NAKANO Shin-ichi
• 金额: $ 9.02万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340245/
• 关键词: Streams; Biofilms; Microorganisms; Microbial loop; Primary production; Bacterial production; Microsensor; Environmental monitoring; 粘性境界層; 細菌; 原生生物; 付着藻類

We have developed a new sampling method for collecting microorganisms living on pebbles in streams to minimize the loss of microorganisms. Cell densities of bacteria, heterotrophic nanoflagellates and ciliates collected by the new method tended to be higher than those obtained by the conventional method. Significant correlations between concentration of chlorophyll α and cell densities of heterotrophic microorganisms, and among heterotrophic microorganisms suggest the presence of active microbial food webs in streams. As a next step, benthic bacterial cell densities and production rates together with chlorophyll concentration and primary production of periphyton on biofilm pebbles in a stream were analyzed to examine whether primary production supports bacterial production in this natural aquatic biofilm. Percentages of bacterial production to net primary production were calculated as 61 to 435% with the assumption of bacterial growth yield as 30%. Thus, it is likely that both autochthonous and allochthonous supplies of organic matter are important for production of bacteria in the pebble biofilms that develop in fresh water streams. Abundance and composition of microorganisms are susceptible to subtle environmental changes. Hence, we tried to detect the changes in biofilms using Microsensors (Unisense). The Microsensors could determine vertical profiles of current velocity and dissolved oxygen concentration in biofilms. These profiles were different, depending on biofilms. This is attributable to abundance and composition of dominant periphyton algae in biofilms.

我们开发了一种新的采样方法，用于收集生活在溪流中卵石上的微生物，以最大限度地减少微生物的损失。新方法收集的细菌、异养纳米鞭毛虫和纤毛虫的细胞密度往往高于传统方法获得的细胞密度。叶绿素α和异养微生物浓​​度的细胞密度之间以及异养微生物之间表明存在活性微生物食物下一步，分析了溪流中生物膜卵石上的底栖细菌细胞密度和生产率以及叶绿素浓度和附生生物的初级生产，以检查初级生产是否支持该天然水生生物膜中的细菌百分比。假设细菌生长产量为 30%，则计算出的产量占净初级产量的比例为 61% 至 435%，因此，本地和异地都有可能。有机物质对于淡水流中形成的卵石生物膜中的细菌的产生非常重要，微生物的丰度和组成容易受到环境细微变化的影响，因此，我们尝试使用微传感器（Unisense）来检测生物膜的变化。确定生物膜中的电流速度和溶解氧浓度的垂直剖面这些剖面是不同的，这取决于生物膜中主要附生藻类的丰度和组成。生物膜。

项目成果

Miwa Fukuda, Atsuko Ashida, Yuji Tomaru, Shn-ichi Nakano: "An improved method for collecting heterotrophic microorganisms in habiting on pebbles in streams"Limnology. 5(in press). (2004)

Miwa Fukuda、Atsuko Ashida、Yuji Tomaru、Shn-ichi Nakano：“一种收集栖息在溪流卵石上的异养微生物的改进方法”湖沼学。

Miwa Fukuda, Atsuko Ashida, Yuji Tomaru, Shin-ichi Nakano: "An improved method for collecting heterotrophic microorganisms inhabiting on pebbles in streams"Limnology. 5(In press). (2004)

Miwa Fukuda、Atsuko Ashida、Yuji Tomaru、Shin-ichi Nakano：“一种收集栖息在溪流卵石上的异养微生物的改进方法”湖沼学。

Miwa Fukuda, Atsuko Ashida, Yuji Tomaru, Shin-ichi Nakano: "An improved method for collecting heterotrophic microorganisms inhabiting on pebbles in streams"Limnology. 5(印刷中). (2004)

Miwa Fukuda、Atsuko Ashida、Yuji Tomaru、Shin-ichi Nakano：“一种收集栖息在溪流卵石上的异养微生物的改进方法”Limnology 5（出版中）。