Biodegradation of carbazole by Pseudomonas sp. GBS.5 immobilized in polyvinyl alcohol beads

The Pseudomonas sp. GBS.5 cells were immobilized in calcium alginate (2%): PVA (6%) matrix and the carbazole degradation was studied after dissolving the alginate linkages. This matrix was chosen for immobilization based on mechanical stability and immobilized cell viability. The maximum carbazole degradation rate achieved by PVA-alginate immobilized cells was 52.62 ppm h-1 as opposed to 39.06 ppm h-1 by cells immobilized in calcium alginate beads. The effect of cell loading capacity and initial carbazole concentration on carbazole degradation were also studied. The cells immobilized in PVA beads could be stably stored and be repeatedly used for eight cycles at 100 ppm carbazole concentration with high degradation activity. The immobilization process described in the paper resulted in increased carbazole degradation activity and hence the decrease in the cost of operations.