https://www.cas.cn/cm/202412/t20241218_5042841.shtml
China’s soybean dependence on foreign countries is relatively high. Customs data show that in 2023, China imported 160 million tons of grain, of which soybeans accounted for more than 60%, reaching 99.41 million tons. In recent years, global soybean production continued to decline, and the contradiction between supply and demand intensified, pushing up the cost of animal husbandry and affecting China’s food security.
Single-cell protein is a protein resource which can be obtained by large-scale artificial cultivation of yeast, fungi, bacteria and algae. One-carbon raw materials such as methanol, methane, carbon dioxide, and carbon monoxide are widely available and inexpensive. In order to achieve efficient utilization and conversion of one-carbon raw materials, researchers at the CAS Institute of Industrial Biotechnology in Tianjin have constructed a variety of microbial chassis as core catalysts for one-carbon biomanufacturing in recent years, and have achieved a high level of single-cell protein biosynthesis. Based on their studies, in 2023, China has built the first 10,000-ton industrial demonstration plant for Pichia pastoris hydrolyzed protein using methanol as a carbon source, and it has been successfully put into production. The fermentation process used by the factory is safe and efficient, and can run stably and continuously for more than 100 days. The fermentation system is energy-saving and environmentally friendly, and no “three wastes” are produced, which solves the problem of high environmental pressure on fermentation enterprises. The system achieves low cost and high output, and the single-cell protein produced is of high quality.
In September 2024, the factory’s 100,000-ton Pichia pastoris hydrolyzed protein project was successfully signed. After it is put into production, the annual output will be equivalent to the soybean protein equivalent planted on one million mu of land each year.
In addition to one-carbon raw materials, China also has rich industrial and agricultural by-product resources, such as straw, bean dregs, and distiller’s grains, which can also be developed as raw materials for synthesizing single-cell proteins. China’s corn planting area is about 600 million mu, and the output of corn straw is generally 1.3-1.6 times the output of corn grain, about 700 million tons per year. Corn stalks contain a total energy that is basically equivalent to that of ordinary grains, and also contain many nutrients that are beneficial to the growth and development of livestock and poultry. With the support of the National Key R&D Program, technical innovations were made in the breeding and transformation of straw-efficient degradation engineering bacteria, the customized development of enzyme preparations highly compatible with straw structural characteristics, and the creation of bacterial enzyme synergistic solid-state fermentation systems. The Tianjin team has built a complete full-chain technology system for large-scale biosynthesis of feed protein from straw. The technology can be applied to the production of single-cell protein from a variety of industrial and agricultural by-products.
