Microbial degradation of nitrobenzene by immobilized cells of Micrococcus luteus

Micrococcus luteus Z3 was immobilized in polyurethane foam and its ability to degrade nitrobenzene was investigated. Batch experiments showed that polyurethane-foam-immobilized cells possessed a higher degradation capacity. Compared to freely suspended cells (FSC), immobilized cells degraded nitrobenzene more efficiently under alkali and acid conditions, as well as higher temperature. Kinetic studies revealed that higher concentrations of nitrobenzene were better tolerated and more quickly degraded by immobilized cells. Moreover, in the presence of NaCl (<= 10%, w/v) immobilized cells exhibited better tolerance toward salinity. Therefore immobilization of Z3 in polyurethane foam could be a promising method for treating nitrobenzene industrial wastewater, especially with high salinity.