The potential application of polyhydroxyalkanoates as biocontrol agents

Abstract Microbially synthesized biodegradable biopolymers, such as polyhydroxyalkanoates (PHAs), have emerged as alternatives to plastics based on fossil fuels. Despite a wide range of applications, the commercialization of PHAs has been limited by high production costs. Thus, low‐cost production and their application as high‐value products would be decisive factors in circumventing this challenge. Recent advances have focused on applications of PHAs in which biodegradability, biocompatibility, and bioactivity are critical. Research‐based evidence has demonstrated that PHAs, especially their monomers, chemically modified derivatives, and degradation products, exhibit antimicrobial and antipathogenic properties. These factors have contributed to the emergence of PHAs as promising biocontrol agents (BCAs), especially in aquaculture systems that face significant challenges, including antibiotic‐resistant pathogens and disease outbreaks. PHA metabolic products and modifications to their functional groups have been proving more effective in suppressing bacterial virulence, disrupting pathogen metabolism, and enhancing host immune responses. This review summarizes the recent progress in PHA production strategies, structural modification, and functional applications such as BCAs. The potential of PHA‐assisted farming systems to improve animal health is discussed, along with critical challenges and future directions for sustainable deployment. © 2026 Society of Chemical Industry.