SYNTHESIS OF FLUOROACETATE FROM FLUORIDE, GLYCEROL, AND BETA-HYDROXYPYRUVATE BY STREPTOMYCES-CATTLEYA

Streptomyces cattleya produces fluoroacetate and 4-fluorothreonine from inorganic fluoride added to the culture broth. We have shown by F-19 nuclear magnetic resonance (NMR) spectrometry that fluoroacetate is accumulated first in the culture broth and that accumulation of 4-fluorothreonine is next. To show precursors of the carbon skeleton of fluoroacetate, we carried out tracer experiments with various C-14- and C-13-labeled compounds. Radioactivity of [U-C-14]glucose, [U-C-14]glycerol, [U-C-14]serine, and [U-C-14]beta-hydroxypyruvate was incorporated into fluoroacetate to an extent of 0.2 to 0.4%, whereas [3-C-14]pyruvate, [2,3-C-14]succinate, and [U-C-14]aspartate were less efficiently incorporated (0.04 to 0.08%). The addition of [2-C-13]glycerol to the mycelium suspension of Streptomyces cattleya caused exclusive enrichment of the carboxyl carbon of fluoroacetate with C-13; about 40% of carboxyl carbon of fluoroacetate was labeled with C-13. We studied the radioactivity incorporation of [3-C-14]-, [U-C-14]-, and [1-C-14]beta-hydroxypyruvates to show that C-2 and C-3 of beta-hydroxypyruvate are exclusively converted to the carbon skeleton of fluoroacetate. These results suggest that the carbon skeleton of fluoroacetate derives from C-1 and C-2 of glycerol through beta-hydroxypyruvate, whose hydroxyl group is eventually replaced by fluoride.