Removal Mechanism of Hexavalent Chromium by a Novel Strain of Pichia anomala Isolated from Industrial Effluents of Fez （Morocco）

作     者：W. Bahafid H. Sayel N. Tahri Joutey N. EL Ghachtouli 

作者机构：Microbial Biotechnology Laboratory Faculty of Sciences and Technology Sidi Mohammed Ben Abdellah University Fez 30000Morocco 

出 版 物：《Journal of Environmental Science and Engineering》 (环境科学与工程（英文版）)

年 卷 期：2011年第5卷第8期

页      面：980-991页

学科分类：0710[理学-生物学] 082803[工学-农业生物环境与能源工程] 07[理学] 08[工学] 0828[工学-农业工程] 09[农学] 0804[工学-仪器科学与技术] 071007[理学-遗传学] 0901[农学-作物学] 0836[工学-生物工程] 090102[农学-作物遗传育种] 

主　　题：Bioremediation Cr(VI) removal Cr(VI) tolerant yeasts Pichia anomala 

摘      要：Hexavalent chromium （Cr（VI）） pollution has become one of the most serious environmental problems today. One removal strategy comprises the microbial reduction of Cr（VI）, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters. In this work a yeast strain that exhibits high Cr（VI） resistance was isolated from soil sediment. The isolated yeast was identified as Pichia anomala by sequencing analysis. The yeast showed a remarkable capacity to completely reduce 25 and 50 mg/L of Cr（VI） in 48 h under aerobic conditions. The increase of initial Cr（VI） concentration influenced reduction, growth and specific growth rate. This strain also exhibited multiple heavy metal tolerance. The presence of anions and cations in the medium had a great influence on chromium reduction. Fractionation of the cells showed that the mechanism of Cr（VI） removal by this strain is ＂adsorption-coupled reduction＂ and the hexavalent chromate reductase activity was expressed constitutively. FTIR analysis of the biomass exposed to chromium showed that the binding process of the chromium ions involves the active participation of functional groups present in the external surface of biomass. High Cr（VI） concentration resistance and high Cr（VI） reducing ability of this strain make it a suitable candidate for bioremediation.