SOME PRODUCTS OF C 14 O 2 FIXATION BY HYDROGENOMONAS FACILIS

Abstract

C14O2 assimilation by H. facilis was studied using chromatographic and radioautographic techniques, Phospho-glyceric acid, fructose-6-phosphate, sedoheptulose-7-phosphate, and ribulose diphosphate are products of assimilation for 45 seconds and 25 seconds under autotrophic conditions. Under heterotrophic conditions, qualitatively similar labelling occurs but with intermediates labeled to a lesser extent. 2, 4-dinitrophenol (2x10-4 [image]) apparently blocks the formation of these sugar phosphates from phosphoglyceric acid during 45-second fixation under autotrophic conditions and completely inhibits heterotrophic fixation for this length of exposure. Alanine, aspartic acid, glutamic acid, glycine, serine, and threonine are products of 1-minute autotrophic fixation, whereas glutamic acid is a major product of 1-minute heterotrophic fixation.