Metagenomic Analysis of Microbial Communities from an Acidic Hot Spring in Northern Taiwan

• Main Authors: Kuei-Han Lin, 林奎含
• Other Authors: 于宏燦
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/16726084679436351963

碩士 === 國立臺灣大學 === 動物學研究所 === 101 === Researches of ecosystems in extreme environments have been critical to the accumulation of fundamental knowledge in fields of earth history, evolution biology and astrobiology. Novel enzymes, molecules possessed by microorganisms in extreme environments also provide sources for potent molecular biological and biotechnical applications. Extreme environments such as hot springs are commonly seen in Taiwan. Previous studies relevant to hot spring microbial ecosystems in the Tatun Volcanic Group area (TVG, northern Taiwan) relied mainly on SSU rRNA gene sequence analyses, which were unilateral and could be possibly biased. To obtain a more realistic view of prokaryotic diversity by acquiring sufficient sequence information, next-generation sequencing (NGS) was applied to this study with the aid of bioinformatics. Through the investigations on metagenomes from microbial community in a hot spring in SHP area, this study was aimed to obtain an overview on prokaryotic diversity, community structure and function in the hydrothermal spring system. According to the results, the average pH of the hot spring in SHP area was 2.8, and average temperature was 73°C. Cell density of planktonic prokaryotes was estimated to be 7.3×105/mL, which was about 10 times lower than that of terrestrial fresh water and salt lakes. Metagenomic DNAs extracted from SHP hot spring were used for construction of a fosmid library containing 9481 clones. DNAs extracted from hot spring water and DNAs of 1485 clones from fosmid library were sequenced using IlluminaTM platform. Analyses of community composition revealed dominance of bacteria over archaea by 7:3 to 8:2. Members of bacterial phylum Aquificae were abundant, followed by Proteobacteria and Firmicutes; members of phylum Crenarchaeota were most abundant among archaea. Sequences from predominant members of genus Hydrogenobaculum, affiliated with Aquificae, were mapped to the reference genome and certain level of sequence difference was found in the comparison. By analysis of the protein COG distribution pattern and comparing results from the other research, the hot spring prokaryotic community in SHP displayed a higher proportion of metabolism-related functions encoded in their genomes.