Alternatives to conventional plastics: Polyhydroxyalkanoates (PHA) from microbial sources and recent approaches - A review

Imagine a world where plastic doesn't harm our environment, that's what Polyhydroxyalkanoates (PHAs) could offer us. These amazing materials represent an innovative class of biodegradable polymers offering sustainable alternatives to conventional plastics. Synthesized by a range of microbial strains, PHAs are valued for their environmental compatibility, biocompatibility, and versatility. This review delves into microbial production of PHAs, focusing on Pseudomonas putida, Bacillus sp., Ralstonia eutropha, Cyanobacteria, Methanogens, and Algal biomass along with different co-polymers, highlighting their customizable properties and enhanced functionalities for diverse applications. However, PHAs production isn't cheap or easy yet, encounters several challenges, including high costs of substrates and downstream processing, which hinder commercial scalability. Recent advancements, such as the utilization of low-cost carbon-rich wastes, eco-friendly extraction solvents, and mixed microbial cultures, have shown promise in overcoming these barriers. Furthermore, metabolic pathway engineering, genetical and morphological modifications in microbes are proving effective in increasing yields and reducing costs. The expanding applications of PHA co-polymers in packaging, agriculture, and medical sectors underscore their pivotal role in transitioning toward a sustainable, plastic-free future. The really exciting part is how versatile these materials are, they could replace plastic in everything from food packaging to medical devices. While we're not quite there yet, PHAs might be our ticket to a future where plastic doesn't outlive us by hundreds of years.