BIODEGRADATION OF 2-CHLOROETHANOL BY FREELY SUSPENDED AND ADSORBED IMMOBILIZED PSEUDOMONAS-PUTIDA US2 IN SOIL

The degradation of 2-chloroethanol by Pseudomonas putida US2 was inves tigated in batch, repeated batch and continuous cultures especially in a packed-bed fermenter with sand. The degradation of 2-chloroethanol was connected with a release of protons, which led to a decrease of th e pH in the medium. Higher initial concentration than 25 mM 2-chloroet hanol were not degraded completely because they entailed a decrease of the pH to 5.0, which inhibited further growth and degradation. P. put ida US2 showed a typical repression of catabolites and diauxic growth with succinate as cosubstrate. The addition of succinate as a second s ubstrate caused a decrease in degradation of 2-chloroethanol. Activate d sludge added to adsorbed cultures in a continuous fermentation did n ot lead to a decrease in metabolic activity. After 2 weeks of continuo us cultivation the specialized strain could be retained.