An Oxidative Pathway for Microbial Utilization of Methylphosphonic Acid as a Phosphate Source

ACS Chem Biol. 2019 Apr 19;14(4):735-741. doi: 10.1021/acschembio.9b00024. Epub 2019 Mar 13.


Methylphosphonic acid is synthesized by marine bacteria and is a prominent component of dissolved organic phosphorus. Consequently, methylphosphonic acid also serves as a source of inorganic phosphate (Pi) for marine bacteria that are starved of this nutrient. Conversion of methylphosphonic acid into Pi is currently only known to occur through the carbon-phosphorus lyase pathway, yielding methane as a byproduct. In this work, we describe an oxidative pathway for the catabolism of methylphosphonic acid in Gimesia maris DSM8797. G. maris can use methylphosphonic acid as Pi sources despite lacking a phn operon encoding a carbon-phosphorus lyase pathway. Instead, the genome contains a locus encoding homologues of the non-heme Fe(II) dependent oxygenases HF130PhnY* and HF130PhnZ, which were previously shown to convert 2-aminoethylphosphonic acid into glycine and Pi. GmPhnY* and GmPhnZ1 were produced in E. coli and purified for characterization in vitro. The substrate specificities of the enzymes were evaluated with a panel of synthetic phosphonates. Via 31P NMR spectroscopy, it is demonstrated that the GmPhnY* converts methylphosphonic acid to hydroxymethylphosphonic acid, which in turn is oxidized by GmPhnZ1 to produce formic acid and Pi. In contrast, 2-aminoethylphosphonic acid is not a substrate for GmPhnY* and is therefore not a substrate for this pathway. These results thus reveal a new metabolic fate for methylphosphonic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Biocatalysis
  • Escherichia coli / metabolism*
  • Lyases / metabolism*
  • Organophosphorus Compounds / metabolism*
  • Oxidation-Reduction
  • Phosphates / metabolism*


  • Bacterial Proteins
  • Organophosphorus Compounds
  • Phosphates
  • methylphosphonic acid
  • Lyases
  • carbon-phosphorus lyase