Chinese scientists have developed a cost-effective method of converting coal into protein, which they say could feed livestock much more efficiently than natural plants while using a tiny fraction of the land, according to reports.

The Chinese Academy of Sciences (CAS) developed a process that first transforms coal into methanol via gasification. That methanol is then fed to a special strain of Pichia pastoris yeast, which ferments the methanol to produce a single-cell protein complete with a range of amino acids, vitamins, inorganic salts, fats and carbohydrates. The resulting organism is much richer in protein than plants are, and it can be used to partially replace fish, soybeans, meat and skimmed milk in a range of animal feeds, scientists reported.

Researchers led by Professor Wu Xin achieved a conversion rate of 92% of the theoretical value. This method boasts a dry cell weight and crude protein content of 120g/liter and 67.2%, respectively.

The team's key innovation was in selecting and genetically engineering the yeast strain, making it more tolerable to the toxic effects of methanol than previous strains to maximize conversion efficiency and minimize the amount of carbon lost during the process.

Researchers have already hooked up with an undisclosed manufacturing partner to start industrial-scale demonstrations that have already produced “thousands of tonnes of this protein in a plant”, local news reported.

Reference:

Gao, L., Meng, J., Dai, W. et al. Deciphering cell wall sensors enabling the construction of robust P. pastoris for single-cell protein production. Biotechnol Biofuels 16, 178 (2023). https://doi.org/10.1186/s13068-023-02428-7