In-vitro biodegradation of discarded marine microplastics across the eastern coast of the Bay of Bengal, India using Exiguobacterium sp.

Discarded marine plastics (DMPs) are emerging pollutants currently attracting significant attention. This present investigation focuses on the collection, characterization, and distribution analysis of DMPs collected from marine sediments followed by isolation and molecular characterization of microplastic-degrading native bacteria sequestered from Chandipur coast sediments, Bay of Bengal India. The study identified two potential microplastic-degrading strains, Exiguobacterium sp. (ON627837) and Bacillus amyloliquefacin (ON653029). The biodegradation investigation of 0.5 g of microplastic incubated under optimized conditions resulted in 4% weight loss after 30 days subject to 200 rpm constant shaking. SEM and FT-IR spectroscopy analysis of the microbial-degraded plastics' surface morphology and composition revealed uneven surfaces with residues compared with the control samples and suggested an abundance of PET (37%) which was further used for bioremediation analysis. This investigation emphasizes the significance of the biodegradation properties of the native bacterial isolates assessing the conditions and degradability of the microorganisms.