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

A.N. Kulakova, D. Hobbs, M. Smithen, E. Pavlov, J.A. Gibert, John Quinn, John McGrath

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

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 23-58% 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 28-55% 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.
Original languageEnglish
Pages (from-to)7799-7803
Number of pages5
JournalEnvironmental Science and Technology
Volume45
Issue number18
Early online date29 Aug 2011
DOIs
Publication statusPublished - 15 Sep 2011

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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