Abstract: The method for treating a microalgal biomass, characterized in the following steps: having a microalgal biomass comprising at least 15% by weight of lipids relative to the total weight of the biomass and having a dry matter concentration of between 1 g/l and 200 g/l, milling said biomass by a bead mill, operated under the following conditions: the mean diameter of the beads (dGM) ranges from 0.2 to 2.5×10?3 m, preferably from 0.4 to 1.0×10?3 m and is preferably approximately 0.6×10?3 m, the blade-tip agitation speed (?) ranges from 4 to 50 m·s?1, preferably from 5 to 20 m·s?1 and is preferably approximately 8 m·sec?1; recovering the composition obtained.