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Diversity analysis of bacterial community in a strongly acid lake

强酸湖细菌群落多样性分析

基本信息

批准号：
11640628
负责人：
SHIKANO Shuichi
金额：
$ 0.58万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640628/
关键词：
bactrial community strongly acid lake Lake Katanuma hydrogen sulfide circulation stratification 16S rRNA gene phylogenetic classification 硫黄酸化細菌

项目摘要

1. The Lake Katanuma, a strongly acid lake, was surveyed during February 1998 to December 2000. The thermal pattern in the lake water showed dimictic, whereas the difference in water temperature between epilimnion and hypolimnion in summer was relatively small due to the volcanic heat supply from the lake bottom. During stratification in summer, the occasional circulations of whole lake water in a short term were observed in 1998 and 1999. Consequently, the condition of high concentration of hydrogen sulfide and oxygen depletion in hypolimnion spread over the whole lake. From September to December, the lake water circulated from the surface to the bottom. In 2000, however, the short-term circulation during summer stagnation was not observed. The occurrence of short-term circulations depends on the weather of that year.2. The changes in the vertical distribution of bacterial biomass were influenced by the seasonal change in stagnation and circulation of lake water. In stratification period, high densities of filamentous bacteria and low abundance of short rods were observed. After the overturn in September, the biomass of filamentous bacteria decreased and that of short rods increased in the whole lake water.3. Phylogenetic analyses of the sequences of 16S rRNA gene show that the strains isolated from lake water fell into proteobacteria alpha subdivision and gamma subdivision. The partial sequences of the strains belonging to alpha proteobacteria were closely related to that of Methylobacterium fujisawaense. The strains of gamma proteobacteria show distinct similarities to sequences of Lysobacter enzymogenes and the iron oxidizing lithotrophs, suggesting that these strains may act as autotrophs.Further studies in terms of the phylogenetic analyses by rDNA sequences directly retrieved from the lake water are needed.

1.片沼湖是一个强酸性湖，在1998年2月至2000年12月期间进行了调查。湖水的热分布呈二分型，但由于湖底火山热的供给，夏季上层与下层的水温差异较小。1998年和1999年，在夏季分层过程中，出现了短时的湖水环流。因此，整个湖泊都处于低层缺氧和高浓度硫化氢的状态。从9月到12月，湖水从表面循环到底部。然而，2000年夏季停滞期间的短期环流没有观察到。短期环流的出现取决于当年的天气。细菌生物量垂直分布的变化受湖水滞流和环流季节变化的影响。在层积阶段，丝状菌密度较高，短杆状菌丰度较低。9月翻覆后，整个湖水中丝状细菌生物量减少，短杆菌生物量增加. 16 SrRNA基因序列的系统发育分析表明，从湖水中分离的菌株属于变形菌门α亚门和γ亚门。属于α变形菌的菌株的部分序列与藤泽甲基杆菌的部分序列密切相关。γ-变形菌与产酶溶杆菌（Lysobacter enzymogenes）和铁氧化石养菌（Iron oxidizing lithotrophs）的rDNA序列具有明显的相似性，提示γ-变形菌可能是自养菌，但仍需进一步利用直接从湖水中提取的rDNA序列进行系统发育分析。