Abstract: Provided are a method for preparing starch using carbon dioxide, a recombinant microorganism, a method for constructing the recombinant microorganism, and a reagent. The method for preparing starch using carbon dioxide comprises: (1) providing energy and carbon sources for microbial cells on the basis of carbon dioxide and extracellular non-optical energy; and (2) generating starch within the microbial cells on the basis of at least one of up-regulated glucose-1-phosphate adenylyltransferase and starch synthase in the microbial cells. In this way, by utilizing non-optical energy, such as electric energy or hydrogen energy, starch can be effectively prepared inside the microbial cells by fixing carbon dioxide.

Abstract: A starch biosynthesis method may implement total artificial biosynthesis from simple compounds such as dihydroxyacetone, formaldehyde, formic acid and methanol to starch. By coupling with methods such as chemical reduction of carbon dioxide, even total artificial biosynthesis of starch taking carbon dioxide as a starting raw material can be implemented. The method can utilize carbon dioxide of high concentration and high density and electric energy and hydrogen energy of high energy density, is more suitable for an industrial production mode, and the production cycle is shortened from several months in farming to several days.