Sustainable Production of High-Performance Antimicrobial Scaffold via an Engineered Halomonas Dual-Product Factory

This study presents a transformative "one-pot" biorefinery approach for the simultaneous production of hyaluronic acid (HA) and polyhydroxybutyrate (PHB) using an engineered, non-pathogenic Halomonas bluephagenesis TD01 chassis. By leveraging the principles of Next-Generation Industrial Biotechnology (NGIB), a one-step fermentation process was developed in nutrient-rich 40-LBG-Y medium, achieving a balanced metabolic flux that yielded 1.99 g/L and high-molecular-weight (HMw) HA (9.6 × 10⁶ Da) as the highest HA-Mw reported by heterogeneous bacteria, alongside intracellular PHB (0.68 to 1.6 g/L). A bioactive HA-PHB nanoparticle scaffold was fabricated, exhibiting a highly porous, interconnected 3D sponge-like architecture with a significant particle size shift from 12 nm to 450 nm, confirming successful polymer complexation. Antimicrobial evaluations revealed that the scaffold exhibited preliminary antimicrobial potential against representative Gram-positive and Gram-negative strains against Staphylococcus aureus, Klebsiella variicola, and Candida albicans. Notably, while Pseudomonas aeruginosa metabolically exploited purified HA, the integrated scaffold reversed this effect, providing preliminary antimicrobial potential by sterically hindering bacterial hyaluronidases. Furthermore, Halomonas-derived HA consistently outperformed Moringa oil and complex emulsions in preliminary tests against a wide range of pathogenic microbes. These results demonstrate that this dual-product platform provides a sustainable, cost-effective source of high-performance functional materials for advanced antimicrobial coatings and clinical wound management.