Objectives: To clone and express a diacylglycerol acyltransferase (DGAT) gene from Mortierella alpina in Saccharomyces cerevisiae and characterize oil production and fatty acid composition of the resulting recombinant RESULTS: A new, full-length cDNA, putatively encoding a DGAT, was cloned from M. alpina. We subsequently cloned the gene, except the transmembrane-encoding region, termed MaDGAT, its molecular mass was 31.3 kDa. MaDGAT shares 75% identity with a DGAT from Mortierella verticillata NRRL 6337. A recombinant vector expressing MaDGAT, pYES2-DGAT, was constructed and transformed into S. cerevisiae H1246, a neutral, lipid-deficient quadruple mutant. TLC analysis showed that the recombinant vector restored triacylglycerol biosynthesis and its content in the recombinant strain was 3.9%.
Conclusion: MaDGAT is a novel DGAT gene and could increase TAG biosynthesis in M. alpina or other filamentous fungi, thereby promoting the synthesis of polyunsaturated fatty acids.
Keywords: Diacylglycerol acyltransferase; Heterologous expression; Mortierella alpina; Saccharomyces cerevisiae; Triacylglycerols.