Is organic matter degradation in aquatic ecosystem attributed only to heterotrophic bacteria?

2016 Fiscal Year Final Research Report

• Project/Area Number: 26450245
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Ehime University (2015-2016); University of Tsukuba (2014)
• Principal Investigator: OBAYASHI Yumiko 愛媛大学, 沿岸環境科学研究センター, 助教 (60380284)
• Co-Investigator(Renkei-kenkyūsha): TAKAO Yoshitake 福井県立大学, 海洋生物資源学部, 准教授 (00511304)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 海洋生態系 / 有機物分子変換 / 海洋微生物群集 / 従属栄養性細菌 / 原生生物 / 細胞外加水分解酵素 / 微生物ループ / 物質循環

Outline of Final Research Achievements

Among biogeochemical processes in aquatic environment, degradation and/or transformation of natural organic matter in aquatic ecosystem is one of the most undescribed processes so far. Degradation of organic matter in aquatic ecosystem is generally thought to be attributed to heterotrophic bacteria, however, we hypothesized that not only heterotrophic bacteria but also eukaryotic microbes, especially protists, contribute to organic matter degradation processes in aquatic environment. In this study, we found that some kinds of protists showed high potential activities of extracellular proteases and parts of their enzymes were seemed to be secreted to the surrounding water. Further researches for the contribution of the protists to organic matter degradation in aquatic environment are expected.

Free Research Field

生物地球化学