Waste Streams of the Animal-Processing Industry as Feedstocks to Produce Polyhydroxyalkanoate Biopolyesters

Animal processing industry in the EU-28 states, encompassing slaughterhouses, rendering companies, and others, generates high quantities of waste streams containing about 500,000 t of lipids plus considerable amounts of offal material and meat and bone meal. These materials need to be utilized in a value-creating way, such as via bioconversion towards polyhydroxyalkanoate biopolyesters of diverse molecular composition and various plastic-like features. As a novelty, the present article summarizes for the first time previous and current efforts to utilize these animal-based waste streams for polyhydroxyalkanoate production in terms of selection of suitable microbial production strains, upstream processing of the raw material to generate accessible carbon sources, kinetics of the bioprocess, characterization of the produced biopolyesters of diverse molecular architecture, environmental process assessment, and economic feasibility. Results and conclusion: The compared case studies clearly demonstrate that utilization of animal processing waste as a second generation feedstock for biopolyester production can definitely become an economically viable and sustainable process provided the utilization of optimized microbial strains, tailored feeding regime, short transportation distances, and clear business plans for commercialization of the final products. Most of all, using animal based waste for generation of second generation biopolyesters and second generation biofuel contributes to food security by preserving raw materials of nutritional value. Conflict of interest: The authors declare no conflict of interest.