Sl. Daniel et Hl. Drake, OXALATE-DEPENDENT AND GLYOXYLATE-DEPENDENT GROWTH AND ACETOGENESIS BYCLOSTRIDIUM-THERMOACETICUM, Applied and environmental microbiology, 59(9), 1993, pp. 3062-3069
The acetogenic bacterium Clostridium thermoaceticum ATCC 39073 grew at
the expense of the two-carbon substrates oxalate and glyoxylate. Othe
r two-carbon substrates (acetaldehyde, acetate, ethanol, ethylene glyc
ol, glycolaldehyde, glycolate, and glyoxal) were not growth supportive
. Growth increased linearly with increasing substrate concentrations u
p to 45 mM oxalate and glyoxylate, and supplemental CO2 was not requir
ed for growth. Oxalate and glyoxylate yielded 4.9 and 9.4 g, respectiv
ely, of cell biomass (dry weight) per mol of substrate utilized. Aceta
te was the major reduced end product recovered from oxalate and glyoxy
late cultures. C-14 labeling studies showed that oxalate was subject t
o decarboxylation, and product analysis indicated that oxalate was uti
lized by the following reaction: 4-OOC-COO- + 5H2O --> CH3COO- + 6HCO3
- + OH-. Oxalate- and glyoxylate-dependent growth produced lower aceta
te concentrations per unit of cell biomass synthesized than did H-2-,
CO-, methanol-, formate-, O-methyl-, or glucose-dependent growth. Prot
ein profiles of oxalate-grown cells were dissimilar from protein profi
les of glyoxylate-, CO-, or formate-grown cells, suggesting induction
of new proteins for the utilization of oxalate. C. thermoaceticum DSM
2955 and Clostridium thermoautotrophicum JW 701/3 also grew at the exp
ense of oxalate and glyoxylate. However, oxalate and glyoxylate did no
t support the growth of C. thermoaceticum OMD (a nonautotrophic strain
) or six other species of acetogenic bacteria tested.