Influence of phenol on the biodegradation of pyridine by freely suspended and immobilized Pseudomonas putida MK1

Aims: To study the effect of co-contaminants (phenol) on the biodegradation of pyridine by freely suspended and calcium alginate immobilized bacteria. Methods and Results: Varying concentrations of phenol were added to free and calcium alginate immobilized Pseudomonas putida MK1 (KCTC 12283) to examine the effect of this pollutant on pyridine degradation. When the concentration of phenol reached 0·38 g l−1, pyridine degradation by freely suspended bacteria was inhibited. The increased inhibition with the higher phenol levels was apparent in increased lag times. Pyridine degradation was essentially completely inhibited at 0·5 g l−1 phenol. However, immobilized cells showed tolerance against 0·5 g l−1 phenol and pyridine degradation by immobilized cell could be achieved. Conclusions: This works shows that calcium alginate immobilization of microbial cells can effectively increase the tolerance of P. putida MK1 to phenol and results in increased degradation of pyridine. Significance and Impact of the Study: Treatment of wastewater stream can be negatively affected by the presence of co-pollutants. This work demonstrates the potential of calcium alginate immobilization of microbes to protect cells against compound toxicity resulting in an increase in pollutant degradation.