Direct Quantification of Inorganic Polyphosphate in Microbial Cells Using 4鈥?6-Diamidino-2-Phenylindole (DAPI)

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• 作者：Anna N. Kulakova ; Darragh Hobbs ; Matthew Smithen ; Evgeny Pavlov ; Jack A. Gilbert ; John P. Quinn ; John W. McGrath
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：September 15, 2011
• 年：2011
• 卷：45
• 期：18
• 页码：7799-7803
• 全文大小：774K
• 年卷期：v.45,no.18(September 15, 2011)
• ISSN：1520-5851

文摘

Inorganic polyphosphate (polyP) is increasingly being recognized as an important phosphorus sink within the environment, playing a central role in phosphorus exchange and phosphogenesis. Yet despite the significant advances made in polyP research there is a lack of rapid and efficient analytical approaches for the quantification of polyP accumulation in microbial cultures and environmental samples. A major drawback is the need to extract polyP from cells prior to analysis. Due to extraction inefficiencies this can lead to an underestimation of both intracellular polyP levels and its environmental pool size: we observed 23鈥?8% loss of polyP using standard solutions and current protocols. Here we report a direct fluorescence based DAPI assay system which removes the requirement for prior polyP extraction before quantification. This increased the efficiency of polyP detection by 28鈥?5% in microbial cultures suggesting quantitative measurement of the intracellular polyP pool. It provides a direct polyP assay which combines quantification capability with technical simplicity. This is an important step forward in our ability to explore the role of polyP in cellular biology and biogeochemical nutrient cycling.