Degradation of phorate by <i style="">Azotobacter</i> isolates

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Of 44 <i style="">Azotobacter</i> isolates from the soils of Maharashtra, 29 belonged to <i style="">A. chroococcum</i> and other were <i style="">A. vinelandii</i>. All <i style="">A. chroococcum</i> isolates were efficient in N fixation when tested by acetylene reduction test and also in cotton cv NHH-44. However, they showed variation to phorate tolerance. The maximum tolerance (150 <img src='/image/spc_char/micro.gif'> g/ml) was shown by ACI-17, ACI-18 and ACI-28 isolates. These isolates also showed maximum phorate degradation. TLC and HPLC studies indicated the presence of O,O-diethyl S-{(ethyl sulphonyl) methyl} phosphorothioate, O,O-diethyl S-{(ethyl sulphinyl) methyl} phosphorothioate and diethyl phosphoric acid as degradation products. Plasmid analysis indicated that the genes for phorate degradation might be located on the main chromosome and not on the plasmid. </smarttagtype>