SBIR Phase I: Production of mealworm biomass and recovery of resources from plastic wastes

The broader impact/commercial potential of this Small Business Innovation Research Phase I project includes the development of new methods to biodegrade waste plastics. Plastic waste is an significant environmental burden. Over 300 million tons of plastic are used each year, resulting in millions of tons of persistent plastic waste, some of which can take up to 600 years to degrade. Mealworms (Tenebrio molitor) can digest polystyrene, also known as Styrofoam, a persistent and widespread source of plastic waste. Beta Hatch Inc. is developing a novel approach to reduce plastic waste. As the mealworms feed, they convert polystyrene into protein and biological waste (frass), both valuable nutrient inputs for animal feed or for fertilizer. This project will screen mealworm strains to identify the best candidates for optimization, develop polystyrene feed mixes to improve the efficiency of digestion, and test the end-products to understand how these might be commercial used. The project will also confirm the safety of polystyrene derived biological products (mealworm protein and frass) for use in the production of non-food animals and fiber crops. This work will support the development of novel and commercially viable approaches for biodegradation of plastics. The technical objectives in this Phase I research project are to develop the commercial potential of mealworms for plastic bioremediation. Polystyrene (PS) is a synthetic long-chain hydrocarbon polymer. It is a major waste product that takes up 30% of landfill space. The formation of strong molecular bonds between neighboring styrene monomers makes polystyrene extremely stable and therefore extremely difficult to degrade. Mealworms are the only proven organism capable of depolymerizing and mineralizing polystyrene, with the help of beneficial gut microbes. However, for polystyrene biodegradation to be commercially viable, the efficiency of digestion needs to be increased, and the safety of products derived from PS feeding needs to be assessed. Existing work has shown that there is strain-specific variability in PS digestion, and that PS digestion efficiency is only ~50% without additional nutrients. Further, PS feeding may decrease the fertility of mealworms, which would limit the long-term commercial feasibility of mealworm based PS-digestion. This project will identify mealworm strains that show high potential for polystyrene (PS) digestion, test the ability to breed animals with enhanced PS capability, develop feed mixes for optimal efficiency of PS biodigestion, quantify impacts of PS feeding on mealworm life cycles, and collect preliminary data on toxicity of PS-derived biomass and frass products. These experiments support the objectives of 1) identifying pathways for scaling up PS biodigestion by mealworms, 2) integration of PS wastes as a feed for mealworm farming, and 3) collection of key data on the marketability of end-products from polystyrene digestion. This feasibility project
will also catalyze conversations with customers and regulators on the business challenges and opportunities associated with plastic biodigestion.