Catalyzes the first step in the biosynthesis of ornithine lipids, which are phosphorus-free membrane lipids (Probable). Catalyzes the 3-hydroxyacyl-acyl carrier protein-dependent acylation of ornithine to form lyso-ornithine lipid (LOL) (By similarity). a (3R)-hydroxyacyl-[ACP] + L-ornithine = a lyso-ornithine lipid + H(+) + holo-[ACP] Lipid metabolism. Mutant lacking this gene is unable to produce ornithine lipids. Belongs to the acetyltransferase family. OlsB subfamily.