Can Toxicities Induced by Insecticide Methomyl be Remediated Via Soil Bacteria Ochrobactrum thiophenivorans and Sphingomonas melonis?

Abstract

The research study was about revealing the biochemical response of Gammarus pulex related to insecticide methomyl before and after bioremediation by two soil bacteria species, Ochrobactrum thiophenivorans and Sphingomonas melonis. Catalase (CAT), glutathione S-transferase.(GST), cytochrome. P4501A1 (CYP1A1) activities in G. Pulex related to methomyl solution were investigated in 24h and 96h. ELISA method was used for test studies. CAT enzyme was decreased in Gammarus pulex that was exposed to methomyl after all exposure period (P < 0.05). CAT activities were returned to control results after bioremediation assays. GST enzyme activity was decreased depending on methomyl exposure during 24h but increased during 4days (P < 0.05). After 8days of bioremediation period, GST activity increased again during 24h while decreased during 4days (P < 0.05). CYP1A1 activity increased in Gammarus pulex that was exposed to methomyl after all exposure period (P > 0.05). After bioremediation, statistically significant changes were not revealed in CYP1A1 activities (P > 0.05). According to the results of our study, CYP1A1, CAT, and GST activities in G. pulex sanctioned the capability of Ochrobactrum thiophenivorans and Sphingomonas melonis in methomyl bioremediation. Isolated and enriched Ochrobactrum thiophenivorans and Sphingomonas melonis that were added to 2.5ppb concentrations of methomyl for 8 days. Each day, chemical oxygen demand (COD) and biochemical oxygen demand (BOD5), pH and dissolved oxygen parameters were monitored. At the final phase of the bioremediation step, it was determined that these bacteria have efficient methomyl bioremediation properties in a mixed corsortia at a rate of 86%. These results show that these bacteria can be used for bioremediate the receiving environments that are polluted by these kinds of insecticides.