بررسی برهمکنش 1395-IR strain toruloides Rhodotorula با جیوه بهمنظور فرایندهای زیستپاالیی جیوه از محیطهای آبی.

Introduction: Nowadays, the heavy metals pollution is one of the most important environmental problems. Due to the high cost of common refining methods, the use of microbial biomass is recommended to clean up heavy metals. The aim of this study was to evaluate the interactions of Rhodoterula toruloides strain IR-1395 with mercury. Materials and methods: In this study, the growth rate and types of interactions of the strain IR1395 with mercury in the Sucrose Broth medium were investigated and the amount of mercury accumulated was measured using the Spectrophotometry method. Then, in order to determine the best biosorption conditions, the effect of parameters such as pH, mercury concentration, biomass concentration, contact time, and the temperature was measured. Also, the biosorption was investigated by treated cells with 2,4 dinitrophenol and autoclave. Finally, the biosorbent was characterized by Scanning Electron Microscope equipped with Energy Dispersive X-Ray Analysis. Results: Studies have shown that the maximum growth rate of the strain IR-1395 was after 36 hours and then it entered the stationary phase. Also, this strain was able to the biosorption and bioaccumulation (61.86%) and 10.17% biovolatilization of mercury from the medium at the concentration of 10 mg/l of chloride mercury for seven days. In examining the factors affecting the mercury biosorption, it was indicated that the optimal pH was 4. The highest biosorption was observed at 300 mg/l of mercury in 10 minutes at 15 ˚C. In the study of the effect of 2,4- dinitrophenol treatment and autoclave, it was found that mercury adsorption has reduced by the treated yeast. Finally, the results of the EDX confirmed the biosorption of mercury by this yeast. Discussion and conclusion: By examining the types of interactions of the strain IR-1395 with mercury and its potential in biosorption, it was found that this strain is a valuable microorganism in mercury bioremediation processes from contaminated aquatic environments. [ABSTRACT FROM AUTHOR]