Stable degradation of catechol by Pseudomonas sp. strain NGK1 encapsulated in alginate and polyurethane foam

Abstract

Catechol is a terminal metabolite formed during the degradative pathways of various aromatic compounds, generally pollutants. Pseudomonas sp. strain NGK1 (NCIM 5120), a soil microbe, is capable of utilizing catechol as the carbon and energy source. This bacterium was encapsulated in alginate and polyurethane foam (PUF). The degradation rate of 20 and 40 mM of catechol in shaken batch cultures, repeated batch cultures, and continuous degradation in a packed bed reactor by free cells was compared with the degradation rate by alginate-and PUF-immobilized cells. The degradation for 72 hrs incubation in batch cultures was: free cells, 6 and 4; alginate-encapsulated cells, 15 and 18; and PUF-encapsulated cells, 18 and 30 mM catechol. Further, the alginate- and PUF-encapsulated cells were used in repeated batch degradation of catechol. Alginate- and PUF-encapsulated cells were found more efficient for the degradation than free cells. Continuous degradation in a packed bed reactor was also investigated. The efficiency of both the immobilized systems for the degradation of catechol was examined.