Development of nonradioacitve method for measuring bacterial production rate in aquatic environments

2014 Fiscal Year Final Research Report

• Project/Area Number: 25550019
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: National Institute for Environmental Studies
• Principal Investigator: IMAI AKIO 独立行政法人国立環境研究所, 地域環境研究センター, 研究センター長 (40203286)
• Co-Investigator(Kenkyū-buntansha): SANO Tomoharu (独)国立環境研究所, 主任研究員 (10178808)
• Co-Investigator(Renkei-kenkyūsha): KOMATSU Kazuhiro (独)国立環境研究所, 主任研究員 (20391104) ; TOMIOKA Noriko (独)国立環境研究所, 主任研究員 (40168399)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 細菌生産速度測定法 / 非放射性同位体

Outline of Final Research Achievements

We developed a nonradioactive quantitative measurement of bacterial production using stable isotope nitrogen-15-labeled deoxyadenosine (15N-dA) by liquid chromatography mass spectrometry (LC-MS). The procedures of the 15N-dA method were the incubation of seawater with 15N-dA, the filtration onto a membrane filter, the DNA extraction, the enzymatic hydrolysis of DNA to nucleosides and the quantification of 15N-dA by LC-MS. Incorporation rate of 15N-dA was significantly positively correlated to that of tritium labeled thymidine (3H-TdR) in samples of coastal seawaters. Average 15N-dA : 3H-TdR incorporation ratio was 0.55 with 2.5% and 97.5% confidence intervals of 0.51 and 0.58, respectively. The results indicated that 15N-dA could accurately predict TdR incorporations over a wide range of bacterial production.

Free Research Field

水環境工学