TABLE 1.
Range of organophosphonate substrates utilized by G. caldoxylosilyticus T20 as the sole phosphorus or nitrogen source
| Organophosphonate substrate | Growth (μg of protein ml−1) on substrate asa:
|
|
|---|---|---|
| Sole P source (1 mM) | Sole N source (5 mM) | |
| Positive control | 315 | 300 |
| Negative control | 30 | 20 |
| Methylphosphonate | 30 | − |
| Ethylphosphonate | 40 | − |
| Phenylphosphonate | 45 | − |
| Aminomethylphosphonate | 25 | 20 |
| 2-Aminoethylphosphonate | 45 | 25 |
| 2-Amino-3-phosphono propionate | 75 | 20 |
| Phosphomycin | 20 | − |
| Phosphono formate | 260 | − |
| Phosphono acetate | 50 | − |
| N-[Phosphonomethyl]-glycine (glyphosate) | 310 | 20 |
| Phosphonomethyl-iminodiacetate | 320 | 20 |
| 2-Phosphonopropionate | 60 | − |
| 3-Phosphonopropionate | 40 | 15 |
| 2-Amino-4-phosphono butyrate | 55 | 20 |
| 2-Phosphono butyrate | 110 | − |
| 4-Phosphono butyrate | 40 | − |
a
Results were scored negative if the protein yield, as measured by the method of Ahmad et al. (1), was less than 20% of that of the positive control containing 1 mM inorganic phosphate. Results are the mean of duplicates, which on no occasion varied by more than 5%.