Bioremediation of pesticide contaminated soil utilizing Phanerochaete chrysosporium and a selective microbial consortium

A selected microbial consortium (SMC) capable of degrading two specific herbicides, alachlor (2-chloro-2', 6'-diethyl-N-[methoxymethyl]-acetanilide; AL) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-S-triazine; AT) was isolated from a pesticide-contaminated mix-load site soil.; Evaluation of bioaugmentation as a feasible bioremediation strategy for this highly contaminated mix-load site soil (Site 5A) was initiated using the SMC. Forty-eight percent of AT and 70% of AL were degraded in the inoculated biometers. The first-order rate constants were 0.0064 d-1 and 0.1331 d-1 for AT and AL, respectively. The calculated half-life of AT was 108 d while AL was 5 d. Based on the total net CO 2 produced (0.9481 mM), it was concluded that approximately 10% of the AT and AL initially present was completely mineralized.; This research examined the degradation of AT and AL in contaminated mix-load site soil utilizing an extracellular fungal enzyme solution (EES) derived from the white rot fungus, Phanerochaete chrysosporium. The resulting extracellular enzyme solution had a LiP activity of 149.0 U l -1 and an MnP activity of 77.6 U l-1.; Approximately 32% of the AT (0.2359 mM) and 54% of the AL (0.3424 mM) were transformed by the EES. The pseudo first-order rate constants for AT and AL degradation were 0.0882 and 0.2504 d-1, respectively. The half-life (t1/2) was 8.0 d for AT and 3 d for AL. The net CO 2 produced (0.2308 mM CO2) only represented 4% of the total expected CO2.; Inoculation of the enzyme treated, pesticide-contaminated mix-load site soil with the isolated indigenous SMC resulted in further degradation of both AT and AL. Approximately 52% of the AT (0.3814 mM) and 65% of the AL (0.1982 mM) were transformed. The overall rate constants for AT and AL biodegradation were 0.0050 and 0.0052 d-1, respectively. Based on the net CO2 evolved (1.122 mM CO2 d-1 ), about 12% of the AT and AL initially present was completely mineralized.