Effect of addition of nitrogen, phosphorus and potassium fertilizers on biodegradation of crude oil by marine bacteria

Abstract

Role of marine bacteria <i style="">viz</i>. <i style="">Marinococcus albus, Methylobacterium mesophilicum </i>and<i style=""> Nocardia otitidiscaviarum </i>in bioremediation of crude oil contaminated Alang sea coast has been evaluated in the present study. Optimum concentrations of inorganic nutrients N, P & K as urea, super phos and potash fertilizers respectively on growth and degradation has been determined. Addition of optimum concentrations of N (1%), P (0.5%) and K (0.01%) in combination significantly enhanced biodegradation by 22 to 32%. Bioremediation studies indicated that a Bacterial consortium (BC) exhibited maximum growth and degradation on addition of optimum concentrations of N, P and K. Maximum effect in increase in growth was on a BC (0.54 mg/ml) whereas, maximum effect on increase in degradation was on <i>N. otitidiscaviarum</i> (31.9%). However, complete degradation was not possible due to the presence of recalcitrant molecules and accumulation of toxic metabolites during biodegradation. Three isolates can successfully be used to formulate a successful bioremediation strategy for oil contaminated marine environment.