C1 gas protein: A potential protein substitute for advancing aquaculture sustainability

Abstract Aquaculture has been the fastest‐growing food production sector and is considered to be so in the future. However, aquaculture feed is heavily dependent on wild‐captured forage fish, which is unsustainable, costly and non‐ecofriendly. Hence, the development of sustainable, eco‐friendly, cost‐effective and nutrient‐balanced novel fishmeal alternatives is critical to satisfying the forecasted expansion of aquaculture. Among fishmeal alternatives, attention to one‐carbon gas protein (C1GP) has reached an unprecedented level recently. The C1GP is produced through the fermentation of certain unique microorganisms by utilizing the substrates from C1‐related industrial exhaust gases, such as CH 4 , CO and CO 2 , which take much less time, land, water and resources, remove greenhouse gases and waste materials, and offer sustainable protein sources. These C1GP products, either as fishmeal or soybean meal alternatives, have been successfully used in fish and shrimp diets. This review introduces the latest research progress on microorganisms, protein production technology, nutrition and products using C1 gases as substrate, as well as their application in aquafeed. With the rapid development of synthetic biotechnology and engineering technology, it will become an important development field in the future in the construction of new strains and gas fermentation technology with high transformation efficiency, wide adaptation and abundant nutrients for the development of new ingredients for aquaculture.