共同研究報告書


研究区分 開拓型研究

研究課題

 Elucidating psychrophilic algae-bacteria interaction through omics analyses
新規・継続の別 開拓型（1年目/全3年）
研究代表者／所属 北大低温研
研究代表者／職名 助教
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

 高須賀太一 北大農学研究院 助教

2

 堀千明 北大工学研究院 助教

3

 森章一 北大低温研 技術職員

4

 小島久弥 北大低温研 助教

研究目的 This research aims to profile the microbial community of snow in Asahidake and to understand the algae-bacteria interactions of this community. Algae are primary producers in alpine snow， shifting between growth and dormancy， but the regulation between these states are unknown. During growth， algae are green-colored， while dormant algae are red， resulting in green and red snow. Furthermore， bacteria are thought to interact closely with algae. In order to elucidate these interactions， microbial communities of green and red snow will be compared， along with algae and bacteria isolation.
　　
研究内容・成果 We successfully collected red (three samples) and green snow (one sample) from Asahidake in June 2016. We conducted four sampling trips and were able to discover time-points and locations where snow algae are present and establish the logistics of the sampling trip. From our collected samples， we identified the microbial communities present in the red and green snow. Because we had independent replicates of the red snow， we were able to optimize the DNA extraction procedure and demonstrate reproducibility of the sampling and laboratory handling processes.

From our community profiling results， we found that the algal genus Chloromonas dominate in all samples， while the bacterial community profile changes between red and green snow. Bacteria in the subphylum Betaproteobacteria are abundant in all samples， but bacteria in the phylum Bacteroidetes are present only in the red snow. This suggests fundamental differences in the metabolic environment between red and green snow that goes beyond the algal metabolic stage. This is the first time that the microbial community profile was compared between actively growing algae and resting algae in environmental samples with the same dominant green algal species. Currently， we are writing a paper to present the community profile results.

In addition to the sequencing results， we successfully cultured green algal strains that are abundantly present in all samples， Chloromonas sp. and found that a Betaproteobacterium that always co-isolates with the alga. This bacterium has also been isolated in pure culture and we are currently testing whether the Chloromonas sp. is able to grow without the presence of the bacterium in order to further understand whether there is a specific interaction between these two organisms. With our isolates， we are in the process of developing a system to study algae-bacteria interactions in the laboratory.
　　
成果となる論文・学会発表等 Conference presentation:
Terashima， M.， Umezawa， K.， Mori， Shoichi， Fukui， M. "Analysis of microbial community of red snow from alpine snowfields." 2016 JSME Annual Meeting， October 24， 2016.