Interaction of plant secondary metabolites and organic carbon substrates affected on biodegradation of polychlorinated biphenyl.

Using plant secondary metabolites (PSM) as an inducer to stimulate biodegradation of polychlorinated biphenyl (PCB) is considered a promising strategy to remove PCB from the environment. In this study, the effects of PSM including naringin, salicylic acid or biphenyl on PCB biodegradation using soil isolates were tested in mineral salt medium using either soil organic carbon (MSMS) or glucose (MSMG). In addition, the effects of surfactant hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were examined. The results indicated that PCB removal was higher in medium with glucose as carbon substrate than in medium with SOC, and further enhanced with biphenyl amendment. However, interactions between salicylic acid and glucose limited PCB removal in treatments using both chemicals as carbon substrate while PCB removal was sustained in treatment using salicylic acid and SOC. Removal of tetra-chlorinated PCB was improved by adding HP-beta-CD, suggesting increased bioavailability due to surfactant. These results suggest that interaction of organic carbon substrates could influence PCB degradation in contaminated environments.