Biorefinery using one-carbon compounds (C1) as feedstock by enzyme cascade reaction

The chemical industry provides about 10% GDP in China and 4% in Europe. It contributes 15% CO2 emission in China and 4% in Europe, it is still largely based on fossil raw materials and is a major consumer of fossil resources and energy. Since both China and Europe have committed to reducing CO2 emissions from fossil sources in the interest of climate protection, the chemical industry must reduce its fossil consumption.

CO2 can be chemically or biotechnological converted into organic compounds. Hexulose can be precursor of any carbon-based chemical products. In this work, we developed enzyme cascade to produce hexulose from one-carbon compounds (C1), such as formaldehyde. 

The key enzyme hexulose-6-phosphate synthase (HPS), which catalyses hexulose-6-phosphate from formaldehyde and D-ribulose-5-phosphate (D-Ru5P). To improve the conversion, the crystal structure of HPS from Pyrococcus horikoshii was determined at 2.64 Å resolution. The structure was investigated using molecular docking, sequence comparison, and alanine scanning to identify key residues, which affect the catalytic properties. Two mutants were obtained after rational enzyme design, mutant activity was six times higher than the wild-type. The enzyme cascade reaction conditions were optimised to catalyse the formation of D-fructose 6-phosphate from D-xylose and formaldehyde. Fructose can be further converted to any organic compounds by microorganisms. 

Speaker

Prof. Luo Liu, College of Life Science and Technology, Beijing University of Chemical Technology. 

He studied technical biology at Institute for Technical Biochemistry, University of Stuttgart. Now he is associate professor at Beijing University of Chemical Technology. He is focusing on biocatalysis and biotransformation. He is principal researcher of 4 national projects and 3 subprojects, he has more than 100 peer-reviewed articles including ACS catalysis, etc.