A kinetic model of growth and product formation of the anaerobic microorganism Thermoanaerobacter thermohydrosulfuricus

Heitmann, T.; Wenzig, Edda; Mersmann, Alfons

doi:10.1016/0168-1656(96)01567-2

Cited by 5 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The metabolism of C. thermolacticum was thus linked to the growth rate or phase: acetate and ethanol were strictly growth-dependent, whereas lactate was not. Similar results have been reported for C. cellulolyticum growing on cellobiose (Payot et al 1999) and for C. thermohydrosulfuricum on starch (Heitmann et al 1996).…”

Section: Discussionsupporting

confidence: 88%

Metabolism of lactose by Clostridium thermolacticum growing in continuous culture

et al. 2006

View full text Add to dashboard Cite

The objective of the present study was to characterize the metabolism of Clostridium thermolacticum, a thermophilic anaerobic bacterium, growing continuously on lactose (10 g l(-1)) and to determine the enzymes involved in the pathways leading to the formation of the fermentation products. Biomass and metabolites concentration were measured at steady-state for different dilution rates, from 0.013 to 0.19 h(-1). Acetate, ethanol, hydrogen and carbon dioxide were produced at all dilution rates, whereas lactate was detected only for dilution rates below 0.06 h(-1). The presence of several key enzymes involved in lactose metabolism, including beta-galactosidase, glyceraldehyde-3-phosphate dehydrogenase, pyruvate:ferredoxin oxidoreductase, acetate kinase, ethanol dehydrogenase and lactate dehydrogenase, was demonstrated. Finally, the intracellular level of NADH, NAD+, ATP and ADP was also measured for different dilution rates. The production of ethanol and lactate appeared to be linked with the re-oxidation of NADH produced during glycolysis, whereas hydrogen produced should come from reduced ferredoxin generated during pyruvate decarboxylation. To produce more hydrogen or more acetate from lactose, it thus appears that an efficient H2 removal system should be used, based on a physical (membrane) or a biological approach, respectively, by cultivating C. thermolacticum with efficient H2 scavenging and acetate producing microorganisms.

show abstract

Section: Discussionsupporting

confidence: 88%

Metabolism of lactose by Clostridium thermolacticum growing in continuous culture

et al. 2006

View full text Add to dashboard Cite

show abstract

“…The α-amylase of G. thermoleovorans was decreased when the cells entered into the stationary phase; this could be due to increasing lysis of the cells, depletion of nutrients after vigorous growth, or due to production of other biocatalysts such as acidic proteases [fall of pH from neutral (7.0) to acidic (4.5)] and xylanase, as observed in Bacillus coagulans [12]. Lactic acid was detected as a by-product in the fermentation broth of G. thermoleovorans, but ethanol was not detected as observed in Thermoanaerobacter thermohydrosulfuricus by Heitmann et al [34]. The production of ethanol and acetic acid had been reported by Antranikian [35] from Clostridium sp.…”

Section: Discussionmentioning

confidence: 61%

Hyperthermostable, Ca2+-Independent, and High Maltose-Forming α-Amylase Production by an Extreme Thermophile Geobacillus thermoleovorans: Whole Cell Immobilization

Rao

Satyanarayana

2009

Appl Biochem Biotechnol

View full text Add to dashboard Cite

The synthesis of extracellular alpha-amylase in Geobacillus thermoleovorans was constitutive. The enzyme was secreted in metabolizable carbon sources as well as non-metabolizable synthetic analogues of glucose, but the titers were higher in the former than that in the latter. G. thermoleovorans is a fast-growing facultatively anaerobic bacterium that grows under both aerobic and anaerobic conditions and produces an extracellular amylolytic enzyme alpha-amylase with the by-product of lactic acid. G. thermoleovorans is a rich source of various novel thermostable biocatalysts for different industrial applications. alpha-Amylase synthesis was subject to catabolite repression in the presence of high concentrations of glucose. The addition of cAMP to the medium containing glucose did not result in the repression of alpha-amylase synthesis. The addition of maltose (1%) to the starch arginine medium resulted in a twofold enhancement in enzyme titers. Polyurethane foam (PUF)-immobilized cells secreted alpha-amylase, which was higher than that with the free cells. PUF appeared to be a better matrix for immobilization of the thermophilic bacterium than the other commonly used matrices. The repeated use of PUF-immobilized cells was possible over 15 cycles with a sustained alpha-amylase secretion. The use of this enzyme in starch saccharification eliminates the addition of Ca(2+) in starch liquefaction and its subsequent removal by ion exchangers from the product streams.

show abstract

“…To operate the fermentation process effectively and efficiently, kinetic modeling of cell growth and ethanol fermentation is necessary to predict the results of industrial fermentations under optimized conditions . Kinetic modeling of ethanol fermentation is important to understand metabolic processes, to estimate process parameters and their influence on cell growth and product utilization, in the scale‐up of the process and the control of bioreactors .…”

Section: Introductionmentioning

confidence: 99%

“…Thermophilic/thermotolerant microorganisms and thermostable enzymes are of great scientific interest, principally with regard to their potential industrial applications due to their stability at high temperatures . Thermophiles have distinct advantages over mesophiles for ethanol production in terms of increased solubility of substrates, improved mass transfer due to decreased viscosity, increased diffusion rates, high bioconversion rates, ability to use a variety of inexpensive biomass feed‐stocks, low risk of contamination, and facilitated product recovery …”

Section: Introductionmentioning

confidence: 99%

Kinetic studies of ethanol fermentation using Kluyveromyces sp. IIPE453

Kumar

Dheeran

Singh

et al. 2013

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

Background To operate the fermentation process effectively and efficiently, the kinetic modeling of cell growth and ethanol fermentation is necessary to predict the results of industrial fermentations under the optimized conditions. Results A kinetic study was conducted for glucose utilization for growth of the yeast strain Kluyveromyces sp. IIPE453 and ethanol formation. Effect of temperature, pH and initial glucose concentration on cell growth and ethanol formation was studied. The data obtained experimentally were validated with existing kinetic models for product and/or substrate inhibition. Conclusion Of all the models, the Aiba model for substrate inhibition was found to be the best fit to the experimental data for the growth of Kluyveromyces sp. IIPE453, and the Luong model for product inhibition was found to be the best fit for ethanol formation using Kluyveromyces sp. IIPE453. © 2013 Society of Chemical Industry

show abstract

A kinetic model of growth and product formation of the anaerobic microorganism Thermoanaerobacter thermohydrosulfuricus

Cited by 5 publications

References 24 publications

Metabolism of lactose by Clostridium thermolacticum growing in continuous culture

Metabolism of lactose by Clostridium thermolacticum growing in continuous culture

Hyperthermostable, Ca2+-Independent, and High Maltose-Forming α-Amylase Production by an Extreme Thermophile Geobacillus thermoleovorans: Whole Cell Immobilization

Kinetic studies of ethanol fermentation using Kluyveromyces sp. IIPE453

Contact Info

Product

Resources

About