Scientists from Nanyang Technological University, Singapore (NTU Singapore) and Temasek Polytechnic have made a breakthrough in sustainable aquaculture practices by successfully replacing half of the fishmeal protein in the diets of farmed Asian seabass with a ‘single cell protein’ cultivated from microbes in soybean processing wastewater. This innovative approach paves the way for more environmentally friendly fish farming practices by reducing reliance on wild-caught fish for feed and addressing overfishing concerns. The research, led by the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) and Temasek Polytechnic’s Aquaculture Innovation Centre (AIC), highlights the potential of using waste-to-resource methods to enhance food security and waste reduction in the aquaculture industry.
Farmed aquaculture species traditionally rely on feed made from fishmeal, which is unsustainable and contributes to overfishing of the seas. Single cell protein cultivated from food processing wastewater presents a sustainable alternative that can provide essential nutrients for healthy fish growth. The microbes found in soybean processing wastewater contain probiotic potential, making them suitable for cultivating single cell protein. By harnessing these microbial communities, the research team has demonstrated the feasibility of producing a viable protein replacement for fish feed, contributing to the sustainability and circular economy goals outlined in the United Nations Paris Agreement.
The waste-to-resource approach employed in the study involves utilizing food processing wastewater that is free of pathogens and contaminants to grow single cell protein. By repurposing this nutrient-rich wastewater for microbial cultivation, the researchers are able to maximize resource use and reduce waste in the aquaculture industry. The study’s results, published in the peer-reviewed journal Scientific Reports, offer a significant step forward in sustainable aquaculture practices and support NTU’s strategic plan to mitigate human impact on the environment through innovative research.
The research team’s approach involved adding soybean processing wastewater from a Singapore-based food processing company into bioreactors to cultivate single cell protein. The bioreactors were operated under controlled conditions for over four months, demonstrating the feasibility of producing single cell protein at ambient temperatures in tropical regions like Singapore. Feeding two groups of young Asian seabass with diets containing traditional fishmeal and a combination of fishmeal and single cell protein, the study found that both groups of fish grew equally, with the latter group exhibiting more consistent growth. These findings suggest that diets incorporating single cell protein may contribute to more uniform fish growth and offer a sustainable alternative to costly and unsustainable fishmeal.
As the aquaculture industry aims to support Singapore’s nutritional needs through intensive production, the research team’s waste-to-resource approach provides a promising solution to replacing fishmeal with single cell protein. Future research will focus on conducting trials with higher levels of fishmeal replacement and exploring the impact of single cell protein diets on different aquaculture species. By continuing to investigate the potential of using food processing wastewater for sustainable aquaculture feed production, the researchers aim to support the transition to a circular bioeconomy and enhance food security and resilience in the aquaculture industry.
