Organophosphonate metabolism by a moderately halophilic bacterial isolate

Abstract

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. ß

Microbial degradation of organophosphorus compounds

“…It is a representative of the phosphonic acid group of compounds, which is characterized by a direct carbon to phosphorus (C–P) bond. The C–P linkage is chemically and thermally very stable and renders the molecule much more resistant to non‐biological degradation in the environment than its analogues with O‐P linkage (Hayes et al , 2000). Mode of action of glyphosate includes inhibition of the plant enzyme 5‐ enol ‐pyruvyl‐shikimate‐3‐phosphate synthase, which catalyzes synthesis of aromatic amino acids (Fisher et al , 1984; Cole, 1985).…”

“…Recently, a thermophile, Geobacillus caldoxylosilyticus T20 was isolated from a central heating system which also degrades glyphosate by this pathway, utilizing the compound as a sole source of phosphorus (Obojska et al, 2002). A halophilic bacterium, Chromohalobacter marismortui, isolated from soil beneath a road gritting salt pile was capable of utilizing several organophosphonates including aminomethyl phosphonic acid as a source of phosphorus (Hayes et al, 2000). Utilization of aminoalkylphosphonates as a source of nitrogen by different bacterial isolates has been reported (McMullan & Quinn, 1994;Ternana & McMullan, 2000).…”

Utilisation of aminomethane sulfonate by Chromohalobacter marismortui VH1

“…Sulfonate biodegradation, and C^S bond cleavage in particular, is generally accepted to be under control of the sulfur-starvation-induced stimulon, such that these compounds are not degraded except under conditions of sulfur-limitation [7]. As C. marismortui VH1 could utilise certain organophosphonates as phosphorus sources for growth [15], structurally related organosulfonate compounds were chosen which were direct analogues of the organophosphonates previously used. C. marismortui VH1 was screened for growth on methane sulfonate, AMSA, 2-aminoethane sulfonate (taurine), 3-amino-1-propane sulfonate, L-2-amino-3-propane sulfonate (cysteic acid), sulfoacetate and 2-hydroxyethane sulfonate (isethionate) in the presence of 5, 10 and 15% (w/v) NaCl (Table 1).…”

“…A Gram-negative moderate halophile, isolated on the basis of its ability to utilise organophosphonates as sole phosphorus sources for growth [15], was initially identi¢ed as Pseudomonas beijerinckii; this strain has recently been reclassi¢ed as C. marismortui [16]. Liquid culture experiments with C. marismortui VH1 were carried out in de-¢ned halophile medium at 37³C and 150 rpm, in 250 ml Erlenmeyer £asks containing 50 ml medium.…”

Phosphonate metabolism in Helicobacter pylori

“…In addition, phosphonate catabolism has been described in a number of bacteria known to metabolise phosphonates but that lack the genes for the known phosphonate metabolic pathways (Hayes et al 2000;Mendz et al 2005). The Gram-negative, e-Proteobacterium Helicobacter pylori (Marshall and Warren 1983), classified as a Type I carcinogen by the World Health Organisation, has been shown to transport (Ford et al 2007) and degrade two phosphonates, N-phosphonoacetyl-L-aspartate (PALA) and phosphonoacetate (Burns et al 1998).…”