Integrated production of microbial biopolymer (PHA) with other value-added bioproducts: an innovative approach for sustainable production

Polyhydroxyalkanoates (PHA), due to their remarkable biodegradability, biocompatibility, and favorable physical and chemical properties, are tested for applications in the agricultural, industrial, and medical fields in place of conventional plastic. Sustainable microbial PHA production is a challenge because of the economic aspects accrued due to the cost-effective substrates and downstream processing. Different approaches are adopted to circumvent the high economic price of PHA production by co-production, employing recombinant strain, mixed cultures, and low-cost feedstock. The review focuses on the co-production of intracellular microbial PHA with an extracellular value-added product. The present review highlights the feasibility of other bio-based products from the feedstock to offset the cost of PHA production with emphasis on another viable option. The paper discusses the recent progress in the simultaneous production of PHA with exopolysaccharides, pigments, enzymes, bio-surfactants, biofuels which primarily fulfill the criteria of higher yield of PHA, and another high-value product that can be achieved. This approach not only maximizes resource utilization but also provides opportunities for the development of a wide range of sustainable bio-based products to improve the overall feasibility of the process.