Previous Article | Next Article ![]()
J. Bacteriol., Jun 1996, 3140-3145, Vol 178, No. 11
M Misoph and HL Drake
The fermentative capacities of the acetogenic bacterium Peptostreptococcus
productus U-1 (ATCC 35244) were examined. Although acetate was formed from
all the substrates tested, additional products were produced in response to
CO2 limitation. Under CO2-limited conditions, fructose-dependent growth
yielded high levels of lactate as a reduced end product; lactate was also
produced under CO2-enriched conditions when fructose concentrations were
elevated. In the absence of supplemental CO2, xylose-dependent growth
yielded lactate and succinate as major reduced end products. Although
supplemental CO2 and acetogenesis stimulated cell yields on fructose,
xylose-dependent cell yields were decreased in response to CO2 and
acetogenesis. In contrast, glycerol-dependent growth yielded high levels of
ethanol in the absence of supplemental CO2, and pyruvate was subject to
only acetogenic utilization independent of CO2. CO2 pulsing during the
growth of CO2- limited fructose cultures stopped lactate synthesis
immediately, indicating that CO2-limited cells were nonetheless
metabolically poised to respond quickly to exogenous CO2. Resting cells
that were cultivated at the expense of fructose without supplemental CO2
readily consumed fructose in the absence of exogenous CO2 and formed only
lactate. Although the specific activity of lactate dehydrogenase was not
appreciably influenced by supplemental C02 during cultivation, cells
cultivated on fructose under CO2-enriched conditions displayed minimal
capacities to consume fructose in the absence of exogenous CO2. These
results demonstrate that the utilization of alternative fermentations for
the conservation of energy and growth of P. productus U-1 is augmented by
the relative availability of CO2 and growth substrate.
Copyright © 1996, American Society for Microbiology
Effect of CO2 on the fermentation capacities of the acetogen Peptostreptococcus productus U-1
Lehrstuhl fur Okologische Mikrobiologie, BITOK, Universitat Bayreuth, Germany.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»