[A-HW22] 流域生態系における物質輸送と循環：源流から沿岸まで

[AHW22-P21] 琉球石灰岩地域の地下水のメタゲノム解析

*丸山 莉織¹、水澤 奈々美¹、安元 純²、飯島 真理子³、安元 剛¹、廣瀬 美奈⁴、井口 亮³、神保 充¹、渡部 終五¹ (1.北里大学海洋生命科学部、2.琉球大学農学部、3.国立研究開発法人　産業技術総合研究所、4.トロピカルテクノプラス)

キーワード：メタゲノム解析、地下水、沖縄県、石灰岩地域、細菌

While the microbial community has been considered to play an important role in organic matter decomposition and nutrient cycling in various ecosystems, our current understanding of the microbial community involved in groundwater ecosystem is strikingly insufficient. As a first step to evaluate the effect of the groundwater on coastal ecosystem, we performed metagenomic analysis on the groundwater of the Okinawajima in the southernmost region of Japan, along with measurement of environmental factors. Groundwater samples were collected from the Yaese Town characterized by high agricultural activities. Samples were filtered through 0.2 µm pore size filter and DNA were extracted from these filters using DNeasy PowerWater Kit (QIAGEN) for shotgun metagenomic analysis. The shotgun data of the groundwater showed that bacteria accounted for 93-98% of the total bacteria at the domain level for all the sampling locations, and Proteobacteria was most dominant at the phylum level, followed by Actinobacteria. Metagenomic analysis revealed the environmental parameters including Oxidation-reduction potential (ORP), Na, Fe and Pb were significantly correlated with certain microbial communities in the groundwater. Further studies are needed to elucidate how the bacterial communities are associated with organic matter decomposition and nutrient cycling in the groundwater and subsequent effects of its submarine discharge on coastal ecosystem.