Isolation and characterisation of ethoprophos-degrading bacteria

An enrichment culture technique was used to isolate bacteria responsible fo r the enhanced biodegradation of ethoprophos in a soil From Northern Greece . Restriction fragment length polymorphism patterns of the 16S rRNA gene, p artial 16S rRNA sequence analysis, and sodium dodecylsulfate-polyacrylamide gel electrophoresis total protein profile analysis were used to characteri se the isolated bacteria. Two of the three ethoprophos-degrading cultures w ere pure and both isolates were classified as strains of Pseudomonas putida (epI and epII). The third culture comprised three distinct components, a s train identical to P. putida epI and two strains with 16S rRNA sequence sim ilarity to Enterobacter strains. Isolate epI effectively removed a fresh et hoprophos addition from both fumigated and non-fumigated soil when introduc ed at high inoculum density, but removed it only from fumigated soil at low inoculum density. Isolates epI and epII degraded cadusafos, isazofos, isof enphos and fenamiphos, but only at a slow rate. This high substrate specifi city was attributed to minor (cadusafos), or major (isazofos, isofenphos, f enamiphos) structural differences from ethoprophos. Studies with C-14-label led ethoprophos indicated that isolates epI and epII degraded the nematicid e by removing the S-propyl moiety. (C) 2000 Federation of European Microbio logical Societies. Published by Elsevier Science B.V. All rights reserved.