[M-ZZ43] Geoparks and Sustainability

[MZZ43-P04] Microorganisms inhabiting various hot springs and the possibility of biomineralization by these organisms in Yuzawa City, Akita Prefecture

*Haruki Takayanagi¹ (1.Yuzawa Geopark Promotion Council)

Keywords:geothermal heat, thermophilic bacteria and archaea, hot springs

Geothermal heat and melt water from heavy snowfalls are abundant in Yuzawa City, Akita Prefecture, and various hot springs are formed by their combination. Thermophilic bacteria and archaebacteria are expected to live in these hot springs, depending on the water quality, but their presence has not been recorded. In this study, we analyzed and identified major hot spring algae, focusing on the psbA gene, and comprehensively analyzed thermophilic bacteria and archaea in the soil, focusing on the 16S rRNA gene.
Our study revealed the presence of dominant microorganisms at each survey point. The dominant genera at each hot spring were as follows: Sulfolobus in the soil and Cyanidiococcus in the opaline silica rock of Arayu; Galdieria on the rock surface near the source of Kawarage Ohyutaki; Thermoleptolyngbya under the water surface and Chloroflexus, Roseiflexus, and Thermosynechococcus at the hot spring spout in Kawara no Yukko; Cloacibacterium in the mud volcanoes of Doroyu Onsen; Thermoleptolyngbya on the rock surface of Ohyu Onsen; and Thermocrinis in the soil and Thermoleptolyngbya on rock wall surface of Oyasukyo Daifunto.
Among these survey sites are locations where rocks such as Jarosite and Geyserite (or Siliceous oolite) are produced, suggesting the possibility of biomineralization. Further investigations should clarify these relationships in detail.