Recovery and microbial synthesis of high-value aquaculture feed additives from food-processing wastewater

By 2050 the World’s population is expected to reach 9 billion, which combined with improving diets will increase demand for animal protein; hence, crop production will have to increase by 60% to feed livestock and aquaculture. This highlights the need for a fundamental reorientation of the food supply chain towards greater resource efficiency. Developing more sustainable animal feed sources, and advanced resource recycling technologies, is key to decoupling economic growth from the overuse of natural resources, ensuring food security and mitigating the environmental impact of waste streams. Our goal is to develop an integrated sustainability approach in the food industry through advanced resource recycling of food-processing wastewaters to produce high-quality aquaculture feed. This multidisciplinary proposal brings together industrial knowhow and research expertise in the fields of environmental biotechnology, biochemical engineering, biosynthesis, food quality and animal nutrition in Singapore. In the first stage, wastewaters from key breweries, soy sauce and soy milk industries in Singapore will be screened. Their potential will be evaluated by analysing their chemical and microbial properties, and the most valuable stream selected for advanced resource recovery. This will entail a stepwise approach: 1) initial separation of valuable products; 2) production of feed-grade microbial products from the wastewater, 3) formulation of high-value feed additives; and, 4) aquaculture trials using these products and/or additives. Additionally, the absence of pathogens, antimicrobial resistance genes, and toxins will be assessed to ensure the health of the animals, and the resulting effluent treated to recycle energy and water. The sustainability and economic feasibility of the integrated process will be evaluated by comparing it with conventional treatment and feed production, using life cycle analysis and life cycle cost. The methodology developed in this study offers a roadmap toward sustainable resource management, and a case study for other food processing industries and animal feed producers.