[H-CG33] 圏外環境における閉鎖生態系と生物システム

[HCG33-P03] The uniqueness of the dry heat tolerance of akinetes of terrestrial cyanobacterium Nostoc sp. HK-01

*木村 駿太^1,2,3、富田ー横谷 香織³ (1.東京大学大学院 農学生命科学研究科、2.日本学術振興会、3.筑波大学 生命環境系)

キーワード：休眠細胞、乾熱耐性、Nostoc sp. HK-01、陸棲藍藻

Terrestrial cyanobacteria are useful for enabling bio-chemical circulation in closed bio-ecosystems, which is achieved though their photosynthetic ability, nitrogen fixing ability and utility as a food. Dried colonies of the terrestrial cyanobacterium Nostoc sp. HK-01 have a high tolerance to vacuum, UV, gamma-rays, heavy particle beams, and extreme temperatures. Tolerance to extraterrestrial environments is important for transportation in space. Nostoc sp. HK-01 was adopted as a biological material for space exposure experiments (“TANPOPO” mission), because of their high environmental tolerances. Nostoc sp. HK-01 has several different types of cells in its life cycle. We have revealed that the akinete (dormant cell) cell type of Nostoc sp. HK-01 shows tolerance to dry heat. In this study, we tested the dry heat tolerances of cyanobacterial akinetes of several species. We will discuss the uniqueness of the dry heat tolerance of Nostoc sp. HK-01.