An Immobilized Cell System for Biodegradation of Pyrene by Mycobacterium Frederiksbergense

Abstract

Pyrene biodegradation by immobilized cells of Mycobacterium frederiksbergense was investigated in the present study. For immobilizing the cells, ion tropic gelation method using sodium alginate and CaCl₂ as the immobilizing materials was applied. Concentration of sodium alginate was optimized based on immobilized cell growth and mechanical stability of the resulting beads. Based on the results obtained beads prepared using 5% sodium alginate and 3.5% CaCl₂ was chosen for pyrene biodegradation by M. frederiksbergense in which encapsulated silicone oil containing pyrene was used for delivery of pyrene. For a very high pyrene concentration of 2000 mg/l in the oil phase, nearly 90% degradation of pyrene could be achieved by the immobilized cell system without any significant lag phase in degradation. Further, the study indicated the possibility of using non-biocompatible and bio-available non aqueous phase liquid (NAPL) in two phase partitioning bioreactor system for pyrene biodegradation by the immobilized microorganism present in the aqueous phase.

Key Words:

• pyrene
• alginate bead
• biodegradation
• cell immobilization
• Mycobacterium frederiksbergense
• encapsulation

ACKNOWLEDGEMENT

This research work was sponsored by the Department of Biotechnology, Government of India (BT/PR-8844/BCE/08/519/2007).