Acyl-CoA-dependent acyltransferase; part of the gene cluster that mediates the biosynthesis of mannosylerythritol lipids (MELs), surface-active substances that enhance the availability of water-insoluble substrates (Probable) (PubMed:20564650, PubMed:31923270). Depending on the number of acetyl groups, mannosylerythritol lipids can be differentiated into MEL A (fully acetylated), MEL B and MEL C (monoacetylated at R-6 and R-4, respectively), and the fully deacetylated MEL D (By similarity). The first step in the pathway is the generation of mannosylerythritol by the glycosyltransferase EMT1 which catalyzes the transfer of GDP-mannose to the C-4 atom of meso-erythritol (Probable). This reaction has to be stereospecific, since only mannosyl-D-erythritol is generated (Probable). The produced disaccharide is subsequently acylated with fatty acids of various lengths by the acyltransferases MAC1 and MAC2 at positions C-2 and C-3, repectively (Probable). The existence of MEL derivatives which carry an acetyl group at C-2 implies that at least MAC1 also accepts acetyl-CoA as a donor (Probable). The final step of MEL biosynthesis is the acetylation of the fully acylated mannosylerythritol lipids catalyzed by the acetyl-CoA-dependent acetyltransferase MAT1 (Probable). MAT1 displays a relaxed regioselectivity and is able to transfer acetylgroups to both positions C-4 and C-6 of the mannosyl moiety (Probable). Secondary metabolite biosynthesis. Expression is induced when cells are grown in cultures containing vegetable oil as the carbon source. MELs not only have high potential as eco-friendly biosurfactants due to their excellent surface activity, but also have attracted considerable recent interest because of thei runique properties, including self-assembly, anti-tumor and cell differentiation induction activities, and moisturizing and hair-repairing properties. Belongs to the trichothecene O-acetyltransferase family.