Degradation of o-xylene by a novel strain, Zoogloearesiniphila HJ1: Identification, kinetics and metabolic pathway

Abstract

Biodegradation has become a popular alternative remediation technology due to its economical and ecological advantages. A strain able to degrade o-xylene effectively was selected and identified as Zoogloearesiniphila HJ1. The organism, strain HJ1, could degrade o-xylene with concentration as high as 256 mg L–1 at pH 6.8 and 26.3 °C. The Haldane model adequately described the relationship between specific growth rate and substrate concentration. The maximum specific growth rate and yield coefficient were 0.118 h-1 and 0.2572, respectively. A high mineralization rate of 67.9% was observed. Theenzyme activity and metabolic intermediates analysis showed that the ring cleavage of o-xylene was catalyzed by catechol 1,2-dioxygenase, and 3,4-dimethylcatechol was the main metabolic product. The present study demonstrated that the isolated strain, Zoogloearesiniphila HJ1, had a great application prospect for remediation of o-xylene-contaminated environment.