A critical review of the state of knowledge on factors responsible for the degradation in soils of polyhydroxyalkanoates

Abstract

Plastic pollution in the environment, particularly in soils, has become a major ecological concern due to its persistence and potential risks to ecosystems and human health. To mitigate this issue, biodegradable polymers have been developed as sustainable alternatives to conventional plastics. Among them, polyhydroxyalkanoates (PHA) stand out due to their promising biodegradability under diverse environmental conditions. However, their degradation is governed by a complex interplay of intrinsic factors (e.g., chemical structure, crystallinity, molar mass and polydispersity, physical state …) and extrinsic factors (e.g., temperature, humidity, oxygen, microorganisms …), which remain only partially understood. Despite significant research efforts, the methodologies used to assess PHA degradation are often inconsistent or suboptimal, limiting the comparability and reliability of results. This review aims to provide a comprehensive analysis of the impact of these factors on PHA degradation in soils and suggests innovative experimental approaches to further the studies of these degradation processes.