SELECTIVE PLATING MEDIUM FOR ENUMERATION AND RECOVERY OF A HEXACHLOROCYCLOHEXANE-DEGRADING PSEUDOMONAS PTM+ STRAIN FROM SOIL

A double selective plating medium has been developed to enumerate a Ps eudomonas Ptm+ strain capable of assimilating hexachlorocyclohexane (H CH). The ability of the isolate to utilize HCH and/or streptomycin as sole sources of carbon was chosen to impart selectivity. In trials whe n serial 10-fold soil dilutions were spread on HCH plus streptomycin m ineral agar and incubated, the normal microflora did not grow. When so il containing an HCH degrading Pseudomonas was cultured, only the targ et colonies developed. This double selective plating method is suitabl e for environmental monitoring of HCH scavengers as the medium is sens itive, specific and practical.