Starch biosynthesis method

A method for synthesis of starch, comprising pathway of converting starting material compound D, namely dihydroxyacetone, into starch by catalysis with multiple enzymes;

• wherein the pathway comprises the following steps:
• step (1):
• converting the starting material compound D, namely dihydroxyacetone, into a compound F, namely D-glyceraldehyde 3-phosphate, by catalysis with one or more enzymes;
• step (2):
• converting the compound F obtained in step (1) into a compound I, namely D-glucose-6-phosphate, by catalysis with one or more enzymes;
• and
• step (3):
• converting the compound I obtained in step (2) into starch by catalysis with one or more enzymes;
• the enzyme used in step (1) is an enzyme or a combination of enzymes which catalyzes conversion of dihydroxyacetone into D-glyceraldehyde 3-phosphate by one-step or multi-step reaction;
• the enzyme used in step (2) is an enzyme or a combination of enzymes which catalyzes conversion of D-glyceraldehyde 3-phosphate into D-glucose-6-phosphate by one-step or multi-step reaction;
• the enzyme used in step (3) is an enzyme or a combination of enzymes which catalyzes conversion of D-glucose-6-phosphate into amylose or amylopectin by one-step or multi-step reaction.

A method for the synthesis of dihydroxyacetone, comprising pathway of converting starting material methanol into dihydroxyacetone by catalysis with one or more enzymes;

• wherein the pathway comprises the following steps:
• step (1):
• converting starting material methanol into formaldehyde by catalysis with an enzyme having the function of catalyzing conversion of methanol into formaldehyde;
• and
• step (2):
• converting the formaldehyde obtained in step (1) into dihydroxyacetone by catalysis with an enzyme having the function of catalyzing conversion of formaldehyde into dihydroxyacetone;
• preferably, the enzyme having the function of catalyzing conversion of methanol into formaldehyde in step (1) includes, but is not limited to, alcohol oxidase (AOX) or mutants thereof, cholesterol oxidase or mutants thereof, alcohol dehydrogenase (ADH) or mutants thereof, methanol dehydrogenase or mutants thereof, L-threonine-3-dehydrogenase or mutants thereof, cyclohexanol dehydrogenase or mutants thereof, or n-butanol dehydrogenase or mutants thereof;
• the enzyme having the function of catalyzing conversion of formaldehyde into dihydroxyacetone in step (2) includes, but is not limited to, formolase (FLS) or mutants thereof (FLS-M), or glycolaldehyde synthase (GALS) or mutants thereof;
• wherein steps (1) and (2) can be performed simultaneously or step by step;
• when steps (1) and (2) are simultaneously performed, a reaction system comprises substrate methanol, the enzyme having the function of catalyzing conversion of methanol into formaldehyde and the enzyme having the function of catalyzing conversion of formaldehyde into dihydroxyacetone;
• optionally, an auxiliary enzyme such as catalase may also be comprised.