The conversion of D-glucose to L-fucose by Aerobacter cloacae.

L-Fucose (6-deoxy-L-galactose) is widely distributed in nature as a component of serum glycoproteins (a), the blood group substances (3), and many plant (4) and bacterial polysaccharides (5). The pathway of biosynthesis of this compound is unknown. Dudman and Wilkinson (5) reported that Aerobacter cloacae NCTC 5920 produces a polysaccharide which contains approximately equal quantities of L-fucose, D-glucose, D-galactose, and uranic acid. In the present studies, this organism was grown on specifically labeled glucose as the sole source of carbon. The distribution of isotope in the L-fucose was determined and compared with the distribution in n-glucose and Dgalactose of the polysaccharide. The results of these experiments indicate that the specifically labeled n-glucose carbon chain is converted to that of L-fucose, n-glucose, or Dgalactose without significant inversion or randomization of the isotope.