Lignocellulosic biomass as a sustainable carbon source for microbial production of polyhydroxyalkanoates

Growing demand for biodegradable alternatives to conventional plastics has propelled efforts in the study of polyhydroxyalkanoates (PHAs), biodegradable plastics made from renewable carbon sources. This review highlights the utilization of lignocellulosic biowaste as a superior and cost-effective feedstock material for PHA synthesis. An extensive bibliometric review in the Scopus database detected a sudden spike in global PHA publications over the past decade, mostly after 2019, which points towards increasing research and industrial interest in economical bioplastics. The review reports 461 associated studies examining the interaction between PHAs and lignocellulosic biomass, with strong contributions from the United States, India, and China, detailing rising global collaborations. Salient points include (i) a brief introduction to various lignocellulosic biomass such as sugarcane bagasse, rice husk, and wood biomass; (ii) a detailed review of pretreatment processes—mechanical, chemical, and biological—necessary for proper release of sugars and fermentation; and (iii) an evaluation of existing problems and future trends of scale-up of PHA production. This review highlights that the integration of lignocellulosic waste valorization into biorefinery strategies can reduce production costs, advance circular economy performance, and drive the sustainable development of next-generation biodegradable plastics.