Investigation of the Bioremediation of Herbicide Metribuzin with Bacillus subtilis Bacteria at Artifical Agricultural Field

The bioremoval of metribuzin (C8H14N4OS) which is one of the selective herbicide in tomato farming in Turkey was investigated with Bacillus subtilis bacteria under agitated culture conditions and artifical agricultural field. The bacterium was isolated in collected soil samples from one of the agricultural area in Elazig province of Turkey. The area is unexposed to metribuzin before. Five apparatuses were set up and 100 mL of metribuzin in 1750 ppm concentration (advised concentration of tomato farmers) was added to each Erlenmayer flasks. 5, 10, 20, 50 and 100 mL of enriched Bacillus subtilis solutions (in sabouraud dextrose broth) added to these flasks. Each mL of the enriched solutions contains ×107 Colony forming unit (CFU). These flasks were shaken at 160 rpm at 28 0C in sterile conditions for 17 days. In 24 hours intervals, each sample was collected to flasks and chemical oxygen demand (COD) was determined with DR/890 colorimeter by the line of closed reflux method while Biochemical oxygen demand (BOD5)experiments were performed via standard methods 5210D with oxitops. As a result of the study, best removal performance observed in 100 mL Bacillus subtilis as 98% at 17 days in COD. In a soil study, 100 mL mixture of Bacillus subtilis consortia used for bioremediation studies. According to the results of artifical agricultural field study, the bioremediation seen at COD and BOD5 parameters are 99.4% and 96% respectively at the end of 2. week. This experiments have focused that, Bacillus subtilis should be a selective type for bioremediation of metribuzin on receiving environments.