TY - JOUR
T1 - Metabolic properties of Eubacterium pyruvativorans, a ruminal 'hyper-ammonia-producing' anaerobe with metabolic properties analogous to those of Clostridium kluyveri
AU - Wallace, R. John
AU - Chaudhary, Lal C.
AU - Miyagawa, Eiichi
AU - McKain, Nest
AU - Walker, Nicola D.
PY - 2004/9
Y1 - 2004/9
N2 - wEubacterium pyruvativorans 1-6(T) is a non-saccharolytic, arnino-acid-fermenting anaerobe from the rumen, isolated by its ability to grow on pancreatic casein hydrolysate (PCH) as sole C source. This study investigated its metabolic properties and its likely ecological niche. Additional growth was supported by pyruvate, vinyl acetate, and, to a lesser extent, lactate and crotonate, and also by a mixture of amino acids (alanine, glycine, serine and threonine) predicted to be catabolized to pyruvate. No single amino acid supported growth, and peptides were required for growth on amino acids. Alanine, followed by leucine, serine and proline, were used most extensively during growth, but only alanine and asparate were extensively modified before incorporation. Growth on PCH, but not on pyruvate, was increased by the addition of acetate, propionate and butyrate. L-Lactate was fermented incompletely, mainly to acetate, but no laclate-C was incorporated. Propionate and butyrate were utilized during growth, forming valerate and caproate, respectively. Labelling experiments suggested a metabolic pattern where two C atoms of butyrate, valerate and caproate were derived from amino acids, with the others being formed from acetate, propionate and butyrate. The metabolic strategy of E pyruvativorans therefore resembles that of Clostridium kluyveri, which ferments ethanol only when the reaction is coupled to acetate, propionate or butyrate utilization. The fermentative niche of E pyruvativorans appears to be to scavenge amino acids, lactate and possibly other metabolites in order to generate ATIP via acetate formation, using volatile fatty acid elongation with C-2 units derived from other substrates to dispose of reducing equivalents.
AB - wEubacterium pyruvativorans 1-6(T) is a non-saccharolytic, arnino-acid-fermenting anaerobe from the rumen, isolated by its ability to grow on pancreatic casein hydrolysate (PCH) as sole C source. This study investigated its metabolic properties and its likely ecological niche. Additional growth was supported by pyruvate, vinyl acetate, and, to a lesser extent, lactate and crotonate, and also by a mixture of amino acids (alanine, glycine, serine and threonine) predicted to be catabolized to pyruvate. No single amino acid supported growth, and peptides were required for growth on amino acids. Alanine, followed by leucine, serine and proline, were used most extensively during growth, but only alanine and asparate were extensively modified before incorporation. Growth on PCH, but not on pyruvate, was increased by the addition of acetate, propionate and butyrate. L-Lactate was fermented incompletely, mainly to acetate, but no laclate-C was incorporated. Propionate and butyrate were utilized during growth, forming valerate and caproate, respectively. Labelling experiments suggested a metabolic pattern where two C atoms of butyrate, valerate and caproate were derived from amino acids, with the others being formed from acetate, propionate and butyrate. The metabolic strategy of E pyruvativorans therefore resembles that of Clostridium kluyveri, which ferments ethanol only when the reaction is coupled to acetate, propionate or butyrate utilization. The fermentative niche of E pyruvativorans appears to be to scavenge amino acids, lactate and possibly other metabolites in order to generate ATIP via acetate formation, using volatile fatty acid elongation with C-2 units derived from other substrates to dispose of reducing equivalents.
KW - amino acids
KW - Selenomonas ruminantium
KW - SP-NOV
KW - bacteria
KW - rumen
KW - fermentation
KW - Peptostreptococcus
KW - monensin
KW - peptides
KW - sheep
U2 - 10.1099/mic.0.27190-0
DO - 10.1099/mic.0.27190-0
M3 - Article
SN - 1350-0872
VL - 150
SP - 2921
EP - 2930
JO - Microbiology
JF - Microbiology
IS - 9
ER -