ORIGINAL PAPER Marine bacterial biodegradation of low-density polyethylene (LDPE) plastic Shrikant D. Khandare . Doongar R. Chaudhary . Bhavanath Jha Received: 3 January 2020 / Accepted: 13 January 2021 Ó The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature 2021 Abstract Polyethylene has considered as non- degradable for decades, and their degradation through marine bacteria has rarely studied. However, LDPE found a significant source of pollution in the marine environment. In the present study, four bacterial strains capable of biodegradation of LDPE were isolated from the marine environment. These bacterial isolates H-237, H-255, H-256 and H-265 were revealed close similarity with Cobetia sp., Halomonas sp., Exigobacterium sp. and Alcanivorax sp., respec- tively based on 16S rRNA gene sequencing method. These bacterial isolates were individually incubated for 90 days supplied with LDPE films as a carbon source using the Bushnell-Haas medium. During the biodegradation assay, bacterial isolates were formed the viable biofilm on the LDPE surface, which decreased the thermal stability of the films. At the end of the incubation study, a maximum weight loss of 1.72% of LDPE film was observed by the bacterial isolate H-255. The bacterial attachment on the film changed the physical structure (surface erosion, roughness and degradation) which were confirmed by field emission scanning electron microscopy and atomic force microscopy. The changes in the chemical structure of the LDPE film were analyzed by Atten- uated total reflection Fourier-transform infrared spec- troscopy (ATR-FTIR). This ATR-FTIR showed the shifting of peaks of C–H stretch and C=C bond stretching and the new peaks formation of C–O and – C=C– bonds in comparison to control LDPE film. Further, biodegradation of LDPE film was also con- firmed by remineralization of carbon and enzymatic activities. This study revealed that the active biodegra- dation of LDPE film by marine bacteria and these bacteria could reduce plastic pollution in the marine environment. Keywords Biodegradation Á Low-density polyethylene Á Marine bacteria Á Marine environment Á Marine pollution Introduction Materials made from polyethylene shown extensive use in domestic and industrial applications. Con- versely, this extensive use of non-degradable and highly inert plastic poses a significant effect on the Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/ s10532-021-09927-0. S. D. Khandare Á D. R. Chaudhary (&) Academy of Scientific and Innovative Research (AcSIR), CSIR, New Delhi, India e-mail: drchaudhary@csmcri.res.in S. D. Khandare Á D. R. Chaudhary Á B. Jha Division of Biotechnology and Phycology, CSIR - Central Salt and Marine Chemicals Research Institute, G. B., Bhavnagar, Gujarat 364 002, India 123 Biodegradation https://doi.org/10.1007/s10532-021-09927-0