Actinomycetes as a Promising Tool for Plastic and Hydrocarbon Biodegradation

Plastics and hydrocarbons are among the most prominent contaminants causing severe harm to the environment. Low-density polyethylene is one of the most commonly used plastics in day-to-day life. The high surface area and hydrophobicity of this plastic material serve as a vector for the transfer of other organic pollutants, like hydrocarbons. Eliminating these pollutants helps combat climate change and provide a safer and more sustainable future for all. Addressing both plastic and hydrocarbon pollution together requires a combination of techniques that target both the contaminants to move toward more sustainable practices. Biodegradation is the most cost-effective and long-term way to deal with this pollution. The key to solving this problem may lie with microorganisms that have diverse metabolism with the ability to utilize complex polymers, and one such potent microbe is the actinomycetes. In this study, we isolated 50 actinomycetes from various plastic dumping sites of Rajkot, Gujarat, and tested them for low-density polyethylene (LDPE) degradation by growing them in to medium having LDPE as a sole carbon source. Furthermore, the clear zone assay was performed to confirm the LDPE degradation. Alkane degradation was confirmed by observing the growth of isolates using hexadecane as a sole carbon source. This LDPE degrading actinomycetes were used for LDPE sheet, and reportedly found 16.2 %, 15.5 %, 14.6 %, and 14 % of weight loss of LDPE sheets. In one month by isolates PUA 20, PUA 35, PUA 11, and PUA 6 were isolated, respectively. Subsequently, plastic deterioration was verified through FTIR analysis, which revealed chemical alterations in the structure of the LDPE sheets. Notably, new absorbance peaks were observed in the spectra of isolates PUA 20, PUA 35, and PUA 11 at 953.54 cm-¹, 1073.79 cm-¹, 1149.35 cm-¹, and 1251.59 cm-¹, indicating the formation of new functional groups associated with polymer degradation.