N-Acetylmannosamine digestion by human oral bacteria.

Abstract

LEACH1 showed that N-acetylneuraminic acid was rapidly metabolized by human saliva and ascribed this to the presence of an inducible aldolase produced by contaminating micro-organisms since such destruction was prevented by the addition of ‘Ledermycin’ or by heating the saliva in boiling water. This appears to be the second step in a process whereby salivary mucoproteins having N-acetylneuraminic acid residues as their non-reducing end groups act as inducer molecules to oral bacteria, producing first a neuraminidase and later an aldolase which cleaves the N-acetylneuraminic acid liberated by the neuraminidase into N-acetylmannosamine and pyruvic acid. Such a sequence has been found by us2 to occur when (α1-glycoprotein, which is present in sputum, is used as an inducer molecule in cultures of Klebsiella aerogenes. We wish to report on the third step whereby N-acetylmannosamine itself is digested.