The invention provides an isolated genetically modified non-mammalian organism, wherein the activity of acyl-CoA: sterol acyltransferase/sterol O-acyltransferase (EC 2.3.1.26) and/or diacylglycerol acyltransferase/diacylglycerol O-acyltranferase (EC 2.3.1.20) and/or lecithin cholesterol acyl transferase/phospholipid: diacylglycerol acyltransferase (EC 2.3.1.158) and/or acyl CoA-wax alcohol acyltransferase (EC 2.3.1.75) is reduced or abolished in comparison with a corresponding wildtype organism, methods of use of such an organism, shuttle vehicles for making such an organism and methods for producing such an organism.
