Microbial glycolipid production under nitrogen limitation and resting cell conditions.

Rhodococcus erythropolis is able to synthesize an anionic trehalose-2,2',3,4-tetraester during cultivation on n-alkanes. Preconditions for an overproduction are nitrogen limitation, temperature- and pH-shift. The optimum carbon source was technical grade n-C-10, which led to 0.35 g g-1 of glycolipid per n-alkane. Electron microscopical observations showed that n-C-14,15 (technical grade) grown cells contained numerous lipid inclusions in contrast to n-C-10 (technical grade) grown cells. Nocardia corynebacteroides synthesizes a novel pentasaccharide lipid and as size products small amounts of trehalose-corynomycolates. Optimum precursors for overproduction are n-alkanes from n-tetradecane to n-hexadecane with yields in the range of 0.17 g g-1 of glycolipid per carbon source.