共同研究報告書


研究区分 開拓型研究

研究課題

 気候変動下における彩雪現象の解明
新規・継続の別 開拓型（1年目/全3年）
研究代表者／所属 ベルリン応用科学大
研究代表者／職名 教授
研究代表者／氏名 寺島美亜

研究分担者／氏名／所属／職名
　
氏　　名
所　　属
職　　名

1

 Jackson Tsuji JAMSTEC 博士研究員

2

 梅澤和寛 静岡県立大 助教

3

 久保響子 鶴岡高専 助教

4

 Rudolf Amann マックスプランク海洋微生物学研究所 教授

5

 福井学 北大低温研

6

 渡邉友浩 北大低温研

研究目的 Colored snow caused by microorganisms in alpine and polar regions is a phenomenon impacting the ecosystem，but the mechanism of its occurrence is not well-understood. The key to understanding this phenomenon under climate change is to elucidate key microbial interactions. The objective of this study is to characterize the microbial communities in colored snow samples. Additionally， this project aims to isolate novel microbes for further physiological characterization and to analyze the metagenome of colored snow communities to elucidate the key metabolic pathways in these environments.
　　
研究内容・成果 We obtained valuable algae-containing colored snow samples from Langhovde， Antarctica. The snow is colored green and numerous microalgal cells were confirmed via microscopy. Several approaches were implemented to characterize this microbial community and to isolate novel bacterial species. Firstly， 18S rRNA and 16S rRNA amplicon sequencing analyses were performed. Through this， we identified that green algae were the dominant eukaryotes in the sample， with most species belong to the Chlorophyceae class， followed by the class Trebouxiophyceae. Aside from green algae， fungi in the division Basidiomycota and flagellates Heteromita were present. For the prokaryotes， Bacteroidia was the dominant class， followed by Gamma- and Alphaproteobacteria. To further characterize key bacterial species in the snow samples， we successfully isolated many colonies from the snow and identified these isolates through 16S Nanopore sequencing. Among these isolates， two strains are of particular interest as they are potentially novel species. These strains will be further characterized in the future. In addition to amplicon sequencing and strain isolation， DNA was extracted from the snow samples for metagenome analysis. The metagenome sequencing was successfully completed and processed， and the data is currently being analyzed. Initial analysis revealed the presence of numerous genes of interests， such as photoreceptors and bacteriorhodopsins. These light-reactive proteins are likely to have significant roles in the microorganisms that are dominant in the colored snow by enabling the accurate detection， utilization， and adaptation to high light intensities in the snow surface environment.
　　
成果となる論文・学会発表等 Terashima， M. “Unlocking the mysteries of snow algae and its associated cryophilic bacteria: An untapped bioresource?”， Presentation at the Exchange Day: Hokkaido University – University of Bremen， Bremen， Germany， 11.12. 2023.