This study investigated the potential of Kappaphycus alvarezii hydrolysates, derived from dilute acid hydrolysis, as a sustainable and cost-effective fermentation substrate for polyhydroxyalkanoate (PHA) production by Cupriavidus necator KCTC 2649. Optimized hydrolysate production was achieved through a factorial experimental design and numerical optimization. Subsequently, the hydrolysate was treated with activated carbon to effectively remove fermentation inhibitors, ensuring its suitability for microbial growth. The treated hydrolysate was then successfully employed as a fermentation substrate in shake flask cultures. Our results demonstrated an optimized total reducing sugar (TRS) concentration of 52.724 g L −1 in the produced hydrolysate. Fermentation yielded a dry cell weight (DCW) of 3.33 g L −1 with a notable PHA content of 53.75% g PHA g DCW −1 . Characterization of the synthesized bioplastic using Fourier-transform infrared (FTIR) spectroscopy and differential thermal and thermogravimetric analysis (DTA-TGA) confirmed the successful production of PHA. These findings suggest that K. alvarezii hydrolysates are a promising and competitive fermentation substrate for PHA production, offering a viable alternative to other seaweed hydrolysates reported in the literature. This research highlights a novel approach to valorize abundant seaweed biomass into value-added bioplastics, contributing to the development of a more sustainable bio-based economy.
Tulipan et al. (2026) studied this question.