南シナ海玄徳環礁における底質微生物群集と環境汚染指標としての可能性

Sediment Microbial Communities and Their Potential Role as Environmental Pollution Indicators in Xuande Atoll, South China Sea.

• Biao Zhang
• Yan Li
• Shi-Zheng Xiang
• Yu Yan
• Rui Yang
• Meng-Ping Lin
• Xue-Mu Wang
• Yu-Long Xue
• Xiang-Yu Guan

抄録

本研究では，南シナ海の玄徳環礁にあるQilian島，Iltis銀行，永興島から39の堆積物サンプルを採取し，微生物群集の構造と分布を解析した．微生物群集は自然環境要因と人間活動の両方の影響を受けていた。病原性や汚染物質の分解に関連する属名や、汚染物質分解に関連する属名は、永興島やイルティスバンクよりも奇連島の方が有意に多く、人間活動による汚染の可能性を示唆していると考えられた。病原性または典型的な汚染物質分解細菌は、海底堆積物中の一般的な細菌集団のほとんどと負の相関関係があり、これらの細菌は深層水層の堆積物中に出現する可能性が高いことがわかった。この共起パターンは、ゴミ処理、農業、船舶からの油流出などの人間活動による汚染や、水深などの環境変化への細菌の適応によるものと考えられます。本研究で得られた知見は、微生物レベルでの人間活動が生態系に及ぼす潜在的な影響を理解するのに役立つ可能性がある。

In this study, 39 sediment samples were collected from Qilian Island, Iltis Bank, and Yongxing Island in Xuande Atoll in the South China Sea (SCS), and the microbial community structures and distribution were analyzed. The microbial community was influenced by both natural environmental factors and human activities. The abundance of genera and , which are associated with pathogenicity and pollutant degradation, were significantly higher in Qilian Island than in Yongxing Island and Iltis Bank, suggesting possible contamination of Qilian Island area through human activities. Pathogenic or typical pollutants-degrading bacteria were found to be negatively correlated with most of the commonly occurring bacterial populations in marine sediment, and these bacteria were more likely to appear in the sediment of deep water layer. This co-occurrence pattern may be due to bacterial adaptation to environmental changes such as depth and contaminations from human activities, including garbage disposal, farming, and oil spills from ships. The findings of this study could help in understanding the potential influences of human activities on the ecosystem at the microbial level.

Copyright © 2020 Zhang, Li, Xiang, Yan, Yang, Lin, Wang, Xue and Guan.