A KINETIC-STUDY ON THE BIOREMEDIATION OF SODIUM-CYANIDE AND ACETONITRILE BY FREE AND IMMOBILIZED CELLS OF PSEUDOMONAS-PUTIDA

Pseudomonas putida capable of utilizing organic nitrile (acetonitrile) and inorganic cyanide (sodium cyanide) as the sole source of carbon and nitrogen was isolated from contaminated industrial sites and waste water. The bacterium possesses nitrile aminohydrolase (EC 3.5.5.1) and amidase (EC 3.5.1.4), which are involved in the transformation of cyanides and nitriles into ammonia and CO2 through the formation of amide as an intermediate. Both of the enzymes have a high selectivity and affinity toward the (CN)-C-- group. The rate of degradation of acetonitrile and sodium cyanide to ammonia and CO2 by the calcium-alginate immobilized cells of P. putida was studied. The rate of reaction during the biodegradation of acetonitrile and sodium cyanide, and the substrate- and product-dependent kinetics of these toxic compounds were studied using free and immobilized cells of P. putida and modeled using a simple Michaelis-Menten equation.