FACTORS AFFECTING POTENTIALS OF CERTAIN BACTERIAL ISOLATES FOR ATRAZINE BIOREMEDIATION

Abstract

Different bacterial isolates from two types of soil with different atrazine applications history were propagated. Four isolates from each soil sample (clay loam and calcareous) were classified, counted, and tested for their atrazine degradation efficacy. Isolates showed good capabilities for degrading 0.06 mM atrazine reached to 47.97 % after 48hrs.  These percentages were found to be correlated to isolates counts in the soil. Calcareous soil isolates showed high intensity for atrazine degradation than to those of clay loam soil isolates.Optimum conditions such as pH, temperature, atrazine concentration, and addition of cobalt chloride influences isolates atrazine degradation efficiencies have been studied. The optimum temperature degree was recorded as 25º C; while at 35º C an enhanced degradation percent was recorded for 0.12 mMof atrazine treatment. Isolates from calcareous soil showed enhancement for atrazine degradation at pH 3 while those of clay loam soil presented the most efficiency at pH 5.  Identification of isolate F was conducted using molecular methods indicating the validity of Pseudomonas sp.