Utilization of organophosphonates by environmental micro‐organisms

A survey of the utilization by environmental micro‐organisms of a range of compounds containing the carbon–phosphorus (C–P) bond was carried out. Elective culture studies indicated that 15 of 19 alkylphosphonates tested served only as a sole source of phosphorus for microbial growth. Their metabolism did not lead to the extracellular release of inorganic phosphate. However, four organophosphonates—phosphonoacetate, phosphonoalanine, 2‐aminoethylphosphonate and phosphonomycin—supported microbial growth when supplied as either a phosphorus source or as a carbon and energy source, with near‐quantitative inorganic phosphate release. Four of five aminoalkylphosphonates tested were also utilized as a nitrogen source in the presence of 1 mmol l−1 inorganic phosphate. In a subsequent screening programme, 99% of bacterial isolates tested were able to utilize 2‐aminoethylphosphonate as a sole phosphorus source, 61% as a nitrogen source, 10% as a source of nitrogen and phosphorus, and 2% as a source of carbon, nitrogen and phosphorus ; 2% of isolates used phosphonoalanine as a nitrogen source. These results suggest that the uptake and metabolism of organophosphonates by bacteria is less `tightly' regulated by phosphorus starvation than has previously been supposed.