Organophosphonate metabolism by a moderately halophilic bacterial isolate

A Gram-negative halophile isolated from soil beneath a road gritting salt pile grew optimally at 10% (w/v) NaCl and was shown most likely to be Chromohalobacter marismortui or Pseudomonas beijerinckii on the basis of 16S rRNA analysis. The strain utilised phosphonoacetate, 2-aminoethyl-, 3-aminopropyl-, 4-aminobutyl-, methyl- and ethyl-phosphonates as phosphorus sources for growth. Differences were observed in the growth rate on different phosphonates and the range of phosphonates utilised at elevated NaCl concentrations, possibly as a result of differentially-induced transport mechanisms. An assay of cell-free extracts of 2-aminoethylphosphonate (2AEP) grown cells showed no detectable 2AEP:pyruvate aminotransferase or phosphonoacetaldehyde hydrolase activity.