Assessment of LDPE degrading potential Aspergillus species isolated from municipal landfill sites of Agra

Abstract

Polythene bags have become an article of common usage in daily life. Huge accumulation of plastic waste cause severe threat to humans, animals and our environment. Recently microbes have become the focus of interest for environment friendly disposal of plastic waste. In present study 18 different types of fungal species were isolated from soil and two fungal species were screened by using polythene powder. The fungal identification was carried out by genomic DNA isolation followed by PCR and ITS rRNA sequencing. BLAST and phylogenetic analysis gave a similarity with the database of Aspergillus flavus and Aspergillus terreus of 99%. The microbial degradation of LDPE was analyzed by SEM and FTIR analysis. SEM results show disruption of surface texture of LDPE film as compared to control. FTIR analysis gives a close view of CH stretching, CH2 deformation, CH2 bending etc. Degradation experiment was done in synthetic media for 4 months and in soil for 9 months. Percentage of weight loss of LDPE film after degradation was 30.6% and 11.4% by A. flavus and A. terreus respectively in soil after 9 months. In synthetic medium percent weight loss of polythene was 14.3% and 13.1% by A. flavus and A. terreus respectively after 4 months. There are scanty reports of fungal biodegradation in soil under natural conditions. 30.6% biodegradation in 9 months period with A. flavus, a species isolated from dumping sites, give hope of degradation of such LDPE’s under environmental conditions without providing any supplement or prior treatment.