DEVELOPMENT OF NOVEL BACTERIAL STRAINS FOR ENHANCED BIODEGRADATION OF PLASTIC POLYMERS BY PROTOPLAST FUSION

摘要

The plastic polymers, polyvinyl chloride (PVC) and polyvinyl alcohol (PVA) biodegrading strains were isolated and developed them into new strains with better biodegradation ability with the help of protoplast fusion technique. A strain of Micrococcussp. PVC-4 was isolated from the plastic waste site having capability for biodegradation of PVC. This isolate was chosen for protoplast fusion with Bacillus sp. PVA-7, a degrader of PVA also isolated from plastic waste site for enhancing its capabilitiesof biodegradation of both the polymers. Protoplasts of Micrococcus sp. PVC-4 with PVC biodegradation capability were obtained by 1 mg/mL lysozyme treatment and protoplasts of Bacillus sp. PVA-7 with PVA biodegradation capability were obtained by additionof 2 mg/mL lysozyme in hypertonic solution. Protoplasts of both the organisms were mixed and allowed to fuse in the fusion fluid containing 40 % PEG 6000. Fusants after regenerating their cell walls in regeneration medium were screened and analyzed forthe presence of PVC degradation marker of one parent and PVA degradation marker of another parent strain. Among the many fusants analyzed, few hybrids were found to be with the desired characteristics. The capabilities of fusants for plastic polymer biodegradation were assayed and compared with the parent strains. These fusants showed substantive increase in plastic biodegradation capability.