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, CH 2 deformation, CH 2 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.

Mycodegradation of low-density polyethylene by Cladosporium sphaerospermum, isolated from platisphere

“…Though weight loss was high in these cases, it takes nearly 90 days whereas C. sphaerospermum used in this study showed weight loss in a week time. The weight loss in LDPE films treated with C. sphaerospermum might be due to consumption of LDPE as a carbon source which is in accordance with previous reports 1 , 36 . The reduction rate (k) of LDPE by C. sphaerospermum was found to be 0.0224/day and the half-life (t 1/2 ) was 30.93 days.…”

“…This result is in accordance with previous reports of LDPE degradation by Aspergillus sp. 1 , 19 . It has been reported that fungal penetration resulted in physical weakening and disintegration of LDPE strip 1 .…”

“… 1 , 19 . It has been reported that fungal penetration resulted in physical weakening and disintegration of LDPE strip 1 . Sanyasi et al 18 reported the appearance of pits, grooves, and corrosion on LDPE strip treated with microalgae due to adhesion molecules or by lignin degrading enzymes.…”

“…Plastics have become an inevitable material in our lives, and it plays a significant role in the global economy 1 . Plastic production increased over time, and approximately three hundred and twenty million tons of plastics are produced every year 2 , 3 .…”

Role of fungi in bioremediation of emerging pollutants

“…These grew on low density polyethylene (LDPE) causing deformations and reducing the weight and tensile strength of the polymer. Other Aspergillus species isolated from landfills include Aspergillus clavatus (Gajendiran et al, 2016), Aspergillus flavus and Aspergillus terreus (Verma and Gupta, 2019) and with, these were also shown to degrade PE. Fusarium oxysporum, Fusarium falciforme and Purpureocillum lilacinum isolated from an abandoned dumpsite in Northern Italy, showed to cause changes in the PE film morphology (Spina et al, 2021).…”