BIODEGRADATION OF CYANIDES, CYANATES AND THIOCYANATES TO AMMONIA AND CARBON-DIOXIDE BY IMMOBILIZED CELLS OF PSEUDOMONAS-PUTIDA

Pseudomonas putida utilizes cyanide as the sole source of carbon and n itrogen, Agar, alginate, and carrageenan were screened as the encapsul ating matrices for P. putida. Alginate-immobilized cells of P. putida degraded sodium cyanide (NaCN) more efficiently than non-immobilized c ells or cells immobilized in agar or carrageenan. The end products of biodegradation of cyanide were identified as ammonia (NH3) and carbon dioxide (CO2), These products changed the medium pH, In bioreactors, t he rate of cyanide degradation increased with an increase in the rate of aeration. Maximum utilization of cyanide was observed at 200 ml min (-1) of aeration, Immobilized cells of P. putida degraded cyanides, cy anates and thiocyanates to NH3 and CO2. Use of Na[C-14]-CN showed that 70% of carbon of Na[C-14]-CN was converted into (CO2)-C-14 and only 1 0% was associated with the cell biomass, The substrate-dependent kinet ics indicated that the K-m and V-max values of P. putida for the subst rate, NaCN were 14 mM and 29 nmol of oxygen consumed mg protein(-1) mi n(-1) respectively.