(489b) Biodegradable Polyhydroxyalkanoate Production from Plasma Oxidized Non-Degradable Polypropylene

The proliferation of plastic wastes represents a significant global environmental threat, with no easy way to breakdown natural in danger without creating further threats such as microscopic fibers that travel up the food chain. This creates a need for a way to repurpose the current world plastic waste as well the creation of more environmentally friendly bio-degradable plastic. Polyhydroxyalkanoates (PHA) are biodegradable and environmental friendly plastics natural produced by many microorganisms, and are potential replacement for petroleum based plastics. In this research, petroleum based polypropylene (PP) was first functionalized by SO₃H group and then oxidized by plasma and UiO-66 catalysts at low temperature (60°C). This resulted in converting 50% of PP into organic acid mixture, mainly formic acid and acetic acid. This organic acid mixture was further used as carbon source in the fermentation process of Pseudomonas putida KT2440 to produce PHA. The simultaneous metabolism of different organic acids in P. putida and the effect acid’s ratio to PHA yield and composition were studied. Two strategies were used to further increase PHA production. First, evolutionary adaptation was performed on P. putida to build up its tolerance to the toxicity of PP-derived acid mixture; second, detoxification methods were also used to remove potential inhibitors in the acid mixture. In this research, we successfully used a non-degradable plastic waste (PP) as feedstock to produce biodegradable PHA, fulfilled the degradation and recycling of plastic waste for the production new biodegradable plastics.