講演情報
[1309-20-07]坑水からのMn酸化菌Sarocladium strictumの分離と培養特性
○盧 星燕1、山路 恵子1、谷内 美月1、松代 雄太1、梶原 海斗1、関口 隆史1、川原 里紗2、小原 義之2 (1. 筑波大学、2. （株）日本海水)
司会：有馬 孝彦（北海道大学）
キーワード：
マンガン酸化菌、Sarocladium strictum、坑水浄化
Mine water often contains high concentrations of heavy metals and is required to purify the water before drainage. Environmental-friendly biological treatments have been paid attention. Mn-oxidizing microbes would be potential candidates to use for mine water purification; because biogenic Mn oxides, which could be formed faster than synthetic ones, can adsorb heavy metals in mine water. The objective of this study was to isolate Mn-oxidizing microbes from mine water at a Mn-enriched mine site in Japan, and to examine the culture characteristics, such as the potential roles in mine water purification.
Water temperature and pH in the mine water were 25.8–27.4°C; pH, 5.74–6.01 in April, June and July, 2024. Additionally, the mine water contained high concentrations of Mn (75.8 mg/L) and HCO3- (728.9 mg/L). Above the water surface, high concentration of CO₂ (14%) was also detected. These factors would influence microbial growth and Mn-oxidizing ability of microbes in mine water; therefore, the influence of each factor on the growth and Mn-oxidizing ability of Sarocladium strictum, a Mn-oxidizing fungus isolated from the mine water, were examined.
The growth of S. strictum was highest at 25°C, and Mn-oxidizing ability was similar between 15 and 30°C. The mycelial growth and Mn-oxidizing ability did not differ between pH 5.5 and 7, indicating water temperature and pH at our study site would be suitable for S. strictum to grow and oxidize Mn. Moreover, S. strictum was incubated on Hay medium (pH6) containing HCO₃⁻ (730 mg/L) under 5% CO₂ at 25°C, which was similar to actual environment. The mycelial growth was enhanced compared with only Hay medium; on the contrary, the Mn-oxidizing ability was not influenced. Our findings indicated that S. strictum adapt to the mine water for growth and Mn oxidation.
Water temperature and pH in the mine water were 25.8–27.4°C; pH, 5.74–6.01 in April, June and July, 2024. Additionally, the mine water contained high concentrations of Mn (75.8 mg/L) and HCO3- (728.9 mg/L). Above the water surface, high concentration of CO₂ (14%) was also detected. These factors would influence microbial growth and Mn-oxidizing ability of microbes in mine water; therefore, the influence of each factor on the growth and Mn-oxidizing ability of Sarocladium strictum, a Mn-oxidizing fungus isolated from the mine water, were examined.
The growth of S. strictum was highest at 25°C, and Mn-oxidizing ability was similar between 15 and 30°C. The mycelial growth and Mn-oxidizing ability did not differ between pH 5.5 and 7, indicating water temperature and pH at our study site would be suitable for S. strictum to grow and oxidize Mn. Moreover, S. strictum was incubated on Hay medium (pH6) containing HCO₃⁻ (730 mg/L) under 5% CO₂ at 25°C, which was similar to actual environment. The mycelial growth was enhanced compared with only Hay medium; on the contrary, the Mn-oxidizing ability was not influenced. Our findings indicated that S. strictum adapt to the mine water for growth and Mn oxidation.