Biodegradation of conventional plastics: Candidate organisms and potential mechanisms

With the benefits of coming at low-cost, being light-weight and having a high formability and durability, conventional plastics are widely used in both industry and daily life. However, because of their durability and extensive half-life with poor degradability and the low recycling rate, large amounts of plastic waste are accumulated in various environments, posing a significant threat to organisms and ecosystems. Compared to conventional physical and chemical degradation, biodegradation of plastic might become a promising and environmentally friendly solution for this problem. One of the aims of this review is to briefly describe the impact of plastics (especially microplastics). To facilitate rapid advancements in the area of plastic biodegradation, this paper provides a comprehensive review of the candidate organisms capable of biodegrading plastics and originating from four categories including natural microorganisms, artificially derived microorganisms, algae and animal organisms. In addition, the potential mechanism during plastic biodegradation and associated driving factors are summarized and discussed. Furthermore, the recent biotechnological progress (e.g. synthetic biology, systems biology, etc.) is highlighted as being key for future research. Finally, innovative research avenues for future studies are proposed. Concluding, our review is addressing the practical application of plastic biodegradation and the plastic pollution, thus necessitating more sustainable developments.