A Synthetic Biology Approach to Recycling Waste Plastic into Biodegradable Plastic

Current reliance on petroplastics is unsustainable. Efforts to replace ubiquitous petroplastics polypropylene (PP) and polyethylene (PE) with bioplastics is currently hindered by cost. Polyhydroxybutyrate (PHB) is a biodegradable polymer with properties suited to replace PP and PE. Unlike many bioplastics, PHB does not require industrial composting; rather, PHB degrades into water and trace amounts of CO2 in only a few weeks. The major bottleneck of introducing PHB to consumer products is raw material costs, which currently drives prices to over five times that of petroplastics. Transfoam will utilize inexpensive waste as a raw material to reduce both the cost and carbon footprint of PHB production. Using SBIR Phase I funds, the complete conversion of waste styrene into PHB will be tested in genetically modified bacteria. Transfoam’s preliminary data and independent published research indicate that PHB can be produced in E. coli, and that styrene metabolism is possible. Transfoam, working with the University of Virginia, will complete three objectives to demonstrate this process is commercially viable: i) heterologous protein expression in E. coli, ii) efficient extraction and purification of PHB, and iii) confirmation of desired physical and chemical properties of PHB. Achievement of these objectives will enable Transfoam to competitively enter the $1.2 billion biodegradable plastics market. Our interested customers include Bio-Pak, Mobius and goodnaturedProducts that offer attached letters of support. The biodegradable plastics market projects a 21.3% CAGR for the next six years; however, the existing ability to serve the growing demand is limited by pricey, unscalable raw materials. Compared to other bioplastic processes, the proposed use of inexpensive waste plastic as feedstock will reduce the reliance on virgin (unused and non-recycled) material in the biopolymer manufacturing process, reducing the cost of production up to 50% and lowering the environmental impact of production. After validating the technical viability of our bioprocess, we will begin testing applications of PHB starting with biopolymer blends. As bioplastic demand increases, affordable additives are needed to meet the rapidly-expanding market applications. Increased accessibility to PHB will allow for a competitive price with bioplastic alternatives, serving the unmet demand. Unlike petroplastics, which fragment into microplastics, PHB offers a nontoxic end of life. Transfoam impacts sustainability at both ends of its product’s lifespan by using existing waste to produce a truly biodegradable replacement and offers three environmental benefits: 1. Recycling existing styrene waste 2. Reducing footprint of PHB production 3. Complete degradation in 6-8 weeks