Screening of a new Kosakonia species for polyethylene biodegradation

Abstract

Polyethylene (PE) is among the most widely used synthetic plastics globally, serving as an essential material in daily life and numerous industries, such as packaging for bottles and food, as well as in the production of toys and pipes. PE is used for various purposes owing to its high durability and low production costs, leading to a steadily increasing demand. However, PE waste is a significant contributor to environmental pollution, posing serious threats to marine and soil ecosystems. Therefore, the efficient decomposition of PE, a synthetic polymer known for its resistance to degradation, using bacteria offers a sustainable and effective method for reusing PE. In this study, we isolated a novel species of Kosakonia, designated Kosakonia cowanii JNU01, from a landfill site, capable of biodegrading PE. K. cowanii JNU01 exhibited the highest cell growth rate in media containing PE, indicating its effectiveness in decomposing PE for use as a sole carbon source in its metabolic pathway. Treatment of PE with K. cowanii JNU01 resulted in the emergence of new chemical functional groups, including hydroxyl, carboxyl, amide, and ether groups, within the inert hydrocarbon structure. Analysis of the PE film treated with K. cowanii JNU01 revealed considerable physical degradation on the film's surface. Additionally, various metabolites released from PE by K. cowanii JNU01 were identified. These findings suggest that K. cowanii JNU01 proves to be an effective candidate bacterium for PE degradation.