Inhibition of Rhizobium trifolii by Yeast Extracts or Glycine is Prevented by Calcium

Abstract

Summary: Washed suspensions and particulate fractions of Pseudomonas aeruginosa paci incorporated radioactivity from [i-14C]decanoic acid into bound 3-hydroxydecanoate, and from [i-14C]dodecanoate into bound 2- and 3-hydroxydodecanoate. Washed suspensions incorporated [i-14C]acetate into all three hydroxyacids, which are components of Lipid A in this organism. Degradation studies suggested that 2-hydroxydodecanoate was synthesized by direct hydroxylation of dodecanoate. Coenzyme A was required for synthesis of both 2- and 3-hydroxydodecanoates, synthesis of the former being stimulated by pyridine nucleotide coenzymes. Coenzyme A could not be replaced by acyl carrier protein which inhibited synthesis, but it was not required if [i-14C]dodecanoyl Coenzyme A was used as substrate. The hydroxyacids appeared to be incorporated into lipopolysaccharide since the radioactivity incorporated was extracted by hot 45% phenol and labelled hydroxyacids were then released only after acid or alkali hydrolysis.