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., respectively 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 Attenuated total reflection Fourier-transform infrared spectroscopy (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 confirmed by remineralization of carbon and enzymatic activities. This study revealed that the active biodegradation of LDPE film by marine bacteria and these bacteria could reduce plastic pollution in the marine environment.

数十年来，聚乙烯一直被认为是不可降解的，而通过海洋细菌降解聚乙烯的研究却很少。但是，LDPE在海洋环境中发现了重要的污染源。在本研究中，从海洋环境中分离出了四种能够降解LDPE的细菌菌株。这些细菌分离株H-237，H-255，H-256和H-265，揭示密切相似Cobetia藻，盐单胞菌，Exigobacterium SP。和Alcanivorax分别基于16S rRNA基因测序方法。使用布什内尔-哈斯（Bushnell-Haas）培养基，将这些分离的细菌单独培养90天，以LDPE膜作为碳源。在生物降解测定过程中，细菌分离物在LDPE表面上形成了可行的生物膜，这降低了膜的热稳定性。在孵育研究结束时，细菌分离物H-255观察到LDPE膜的最大失重为1.72％。薄膜上的细菌附着改变了物理结构（表面腐蚀，粗糙度和降解），这通过场发射扫描电子显微镜和原子力显微镜得以证实。通过衰减全反射傅里叶变换红外光谱（ATR-FTIR）分析LDPE膜的化学结构变化。该ATR-FTIR与对照LDPE膜相比，显示出C–H拉伸和C = C键拉伸的峰移动以及新的C–O和–C = C–键峰形成。另外，通过碳的再矿化和酶活性也证实了LDPE膜的生物降解。这项研究表明，海洋细菌对LDPE薄膜具有积极的生物降解作用，这些细菌可以减少海洋环境中的塑料污染。