Abstract

Qi Yun, Zhao Lin* and Tan Xin

The 3-chlorobenzoate degradation pathway by Rhodococcus erythropolis strain S-7 was studied. Result affirms our previous work. 3-chlorobenzoate was converted initially to chlorocatechol, and then degraded by modified ortho-pathway. R. erythropolis S-7 was able to grow on 3-cholobenzoate as sole growth substrate, but it was unable to grow on any of the other monochlorobenzoate isomers or to degrade these substrates. When glucose was added as grow substrate, strain S-7 can cometabolic degrade 2-chlorobenzoate, but cannot biodegrade 4- chlorobenzoate. Entrapment of strain in four supports(calcium alginate, polyvinyl alcohol, polyvinyl alcohol-calcium alginate and chitosan-calcium alginate) was studied. The surface and internal sturctures of PVA-calcium alginate and chitosancalcium alginate beads were studied by scanning electron microscopy(SEM). Both SEM and 3- chlorobenzoate degradation results showed that PVA-calcium alginate gel can be used as support to immobilized strain cell.