The end products of the metabolism of aromatic amino acids by clostridia

Abstract

The end products of the metabolism of phenylalanine, tyrosine and tryptophan by growing cultures of clostridia have been identified. The species used were Clostridium aminovalericum; C. bifermentans; C. botulinum proteolytic type A; C. botulinum proteolytic type B; C. cochlearium; C. difficile; C. ghoni; C. histolyticum; C. lentoputrescens; C. limosum; C. lituseburense; C. malenomenatum; C. mangenoti; C. propionicum; C. putrefaciens; C. sordellii; C. sporogenes; C. sporosphaeroides; C. sticklandii; C. subterminale; C. tetani; C. tetanomorphum. The mixture of aromatic compounds formed, which depended upon the species, included phenyl acetic acid, phenyl propionic acid, phenyl lactic acid, phenol, p-cresol, p-hydroxy phenyl acetic acid, p-hydroxy phenyl propionic acid, indole, indole acetic acid and indole propionic acid.

On a hitherto unknown fermentation path of several amino acids by proteolytic clostridia

“…The enoate reductase plays an important role in the reductive branch of the scheme. In the meantime we detected enoate reductase in other proteolytic clostridia and according to reports in [8,9] and our own observations the end products (5) and (6) of table 1 are formed. Therefore we assume that the suggested fermentation scheme plays a role in many proteolytic clostridia.…”

“…sporogenes ATCC 3584 was grown in a meat broth supplemented with 0.4% peptone (from Casein, Merck), 0.5% yeast extract (Difco), 0.4% Phe, 0.4% Leu or Be and 4 X lo-M FeS04 or in a peptone medium [8,9]. Cultures (150 ml) grown overnight were harvested at 4000 X g for 5 min at 30°C in an anaerobic box (Coy, Ann Arbor) and washed once with 30 ml 20 mM potassium phosphate buffer containing 145 mM NaCl and 10 mM MgS04.…”

The Lipid Fatty Acids of Proteolytic Clostridia

“…As in our previous work (Elsden et al, 1976;Elsden & Hilton, 1978), we used the type strains of Smith & Hobbs (1974) supplemented where necessary with organisms from our own collection. The organisms used were Clostridium bifi.rmentans NCIB 10716, C. cadaveris NCIB 10676, C. cochlearium ATCC 17787, C. d$ficile NCIB 10666, C. ghoni NCIB 10636, C. glycolicum ATCC 14480, C. histolyticum NCIB 503, C. Zentoputrescens NCIB 10629, C. limosum NCIB 10638, C. lituseburense NCIB 10637, C. ntalenominatum ATCC 25776, C. mangenotii NCIB 10639, C. propionicum NCIB 10656, C. putrefaciens NCIB 9836, C. putrificum NCIB 10677, C. sordellii NCIB 10717, C. spovogenes NCIB 10696, C. sticklandii NCIB 10654, C. subterminale NClB 9384 and C. tetani NCIB 10628; the non-reference strains used were C. caloritokrans NCIB 9360, C. scatologmes NCIB 8855 and C. tetanomorphum NCTC 500.…”

“…The other six species, C. tetanomorphum, C. tetani, C. limosum, C. lentoputrescens, C. malenominaturn and C. cochlearium ferment glutamic acid to acetic and n-butyric acids via the methyl aspartate pathway (Buckel & Barker, 1974;W. Buckel, personal communication); they also have in common the ability to convert tyrosine to phenol (Elsden et al, 1976;M. G. Hilton, unpublished).…”

Purification of 2-hydroxyglutaryl-CoA dehydratase from Acidaminococcus fermentans. An iron-sulfur protein

“…The latter is then activated to the CoAester and dehydrated to (E)-enoyl-CoA which is finally saturated. In addition to these four examples there is some evidence that also threonine [7], tyrosine [6], tryptophan [8], methionine [9] and precursors of glutamate may be fermented by this general pathway as are histidine [lo] and glutamine (Scheme 1). The most interesting reaction of the 2-hydroxyacid pathway is the reversible dehydration of (R)-Zhydroxyacyl-CoA to (9-enoyl-CoA with a syn-geometry [5,111.…”