Method and composition for increasing the accumulation of squalene and specific sterols in yeast

摘要

A method of increasing the accumulation of squalene and specific sterols in yeast comprising increasing the expression level of a structural gene encoding a polypeptide having HMG-CoA reductase activity in a mutant yeast having single or double defects in the expression of sterol biosynthetic enzymes is provided. The expression level of a structural gene is preferably increased by transforming yeast with a recombinant DNA molecule comprising a vector operatively linked to an exogenous DNA segment that encodes a polypeptide having HMG-CoA reductase activity and a promoter that is suitable for driving the expression of the encoded polypeptide in the transformed yeast. The polypeptide having HMG-CoA reductase activity is preferably a truncated, active HMG-CoA reductase enzyme. Recombinant DNA molecules useful for transforming yeast and mutant yeast transformed with such recombinant DNA molecules are also disclosed.