Isolation of selenate resistant Enterobacter from Khouzestan industrial wastewaters

Background and Aim : Nowadays, pollutants cause increasing contamination of the most valuable source of the earth planet, waters. Among this, heavy metals have been attracted high attention because toxicity and inability to biodeterioration which make problems for all organism. With the regard of high costs of physicochemical treatments, bioremediation get attention as an alternative process which use natural materials such as bacteria. Microbial activity is responsible for transformations of at least one-third of periodic table elements. Selenium is a trace essential element which play important roles in many cellular processes; however, it is toxic at micro-molar concentrations.Methods : With this regard, isolation of efficient selenate resistant bacteria was performed from industrial wastewaters, Ahvaz, Khouzestan province using modified Luria-Bertani (mLBA) medium supplemented with ۳۲.۵-۱۲۰۰mM selenate. Study of resistance threshold of one promising isolate and toxicity effect of selenate on it, were investigated using MIC, MBC and disc diffusion methods. Finally, biochemical characterization was done based on Bergey’s manual. Further studies (molecular confirmation and the selenate removal mechanisms) are be doing.Results : Among the ۷۳ gathered isolates, AM۲-W۹a strain showed high resistance ability with MIC/MBC equal to ۶۰۰mM and low inhibition zone diameter was selected for following studies. The results of biochemical identification showed that this isolate was belonged to Enterobacter genus.Conclusion : Therefore, the only solution for recovery of environmental health is designing efficient process such as bioremediation. With the ability of introduced strain, it is necessary to study further its properties to becoming as a suitable candidate for bioremediation purposes.

کلیدواژه ها:

Enterobacter ، selenate ، Khouzestan ، wastewater