Influence of pH and undissociated butyric acid on the production of acetone and butanol in batch cultures of Clostridium acetobutylicum

Monot, Frédéric; Engasser, Jean‐Marc; Petitdemange, H.

doi:10.1007/bf00454381

Cited by 200 publications

(134 citation statements)

References 12 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…In typical batch fermentations, initiation of solventogenesis is associated with a pH-acid effect. Lowering the intracellular pH and thereby increasing the concentration of undissociated butyric acid has a positive effect on the production of acetone and butanol (2,13,14,28,29,38). The alteration of the electron flow by carbon monoxide, a reversible inhibitor of the hydrogenase, can also induce the shift from an acidogenic fermentation to an alcohologenic one (9,20,25,27): alcohol (butanol and ethanol) and lactate production at very high specific rates is obtained, without acetone and little or no acetate and butyrate formation.…”

mentioning

confidence: 99%

Regulation of carbon and electron flow in Clostridium acetobutylicum grown in chemostat culture at neutral pH on mixtures of glucose and glycerol

1994

View full text Add to dashboard Cite

The metabolism of Clostridium acetobutylicum was manipulated, at neutral pH and in chemostat culture, by changing the overall degree of reduction of the substrate, using mixtures of glucose and glycerol. Cultures grown on glucose alone produced only acids, and the intracellular enzymatic pattern indicated the absence of butyraldehyde dehydrogenase activity and very low levels of coenzyme A-transferase, butanol, and ethanol dehydrogenase activities. In contrast, cultures grown on mixtures of glucose and glycerol produced mainly alcohols and low levels of hydrogen. The low production of hydrogen was not associated with a change in the hydrogenase level but was correlated with the induction of a ferredoxin-NAD reductase and a decreased level of NADH-ferredoxin reductase. The production of alcohols was related to the induction of a NAD-dependent butyraldehyde dehydrogenase and to higher expression of NAD-dependent ethanol and butanol dehydrogenases. The coenzyme A-transferase was poorly expressed, and thus no acetone was produced. These changes in the enzymatic pattern, obtained with cultures grown on a mixture of glucose and glycerol, were associated with a 7-fold increase of the intracellular level of NADH and a 2.5-fold increase of the level of ATP.The complex anaerobic metabolism of Clostridium acetobutylicum has been studied in considerable detail in recent years, but the factors involved in triggering the metabolic shift, and the physiological state associated with the transition from the acidogenic to solventogenic phase, are still not totally understood.In a number of studies, the effects of electron flow regulation, nutrient limitation, and end product accumulation on the onset and maintenance of solvent production have been investigated. In typical batch fermentations, initiation of solventogenesis is associated with a pH-acid effect. Lowering the intracellular pH and thereby increasing the concentration of undissociated butyric acid has a positive effect on the production of acetone and butanol (2,13,14,28,29,38). The alteration of the electron flow by carbon monoxide, a reversible inhibitor of the hydrogenase, can also induce the shift from an acidogenic fermentation to an alcohologenic one (9,20,25,27): alcohol (butanol and ethanol) and lactate production at very high specific rates is obtained, without acetone and little or no acetate and butyrate formation. The decrease of hydrogenase activity or concentration by iron limitation conditions (19) specifically yields butanol and ethanol as the major fermentation end products. It has also been shown, in continuous cultures at low pH, that phosphate limitation, nitrogen limitation, and glucose excess are conditions under which primarily solvents are produced by C. acetobutylicum (3,4,35).In this study, the metabolic flexibility of C. acetobutylicum was studied in chemostat culture by increasing the NAD(P)H pressure, using mixtures of glucose and a more reduced chemical like glycerol. The pH of the culture was maintained at 6.5 so that no changes could be r...

show abstract

mentioning

confidence: 99%

Regulation of carbon and electron flow in Clostridium acetobutylicum grown in chemostat culture at neutral pH on mixtures of glucose and glycerol

1994

View full text Add to dashboard Cite

show abstract

“…After producing acetate and butyrate during exponential growth, the organism switches to the formation of acetone, butanol, and ethanol shortly before entering the stationary phase. The mechanisms responsible for the onset of solventogenesis are currently the focus of much scientific research.In batch cultures, the initiation and sustained production of solvents are associated with a low extracellular and intracellular pH and a high undissociated butyric acid concentration (7,15,20). In continuous culture, ATP and NAD(P)H availabilities appear to play a key role in product selectivity.…”

mentioning

confidence: 99%

Regulation of Clostridium acetobutylicum metabolism as revealed by mixed-substrate steady-state continuous cultures: role of NADH/NAD ratio and ATP pool

1994

View full text Add to dashboard Cite

Glycerol-glucose-fed (molar ratio of 2) chemostat cultures of Clostridium acetobutylicum were glucose limited but glycerol sufficient and had a high intracellular NADH/NAD ratio (I. Vasconcelos, L. Girbal, and P. Soucaille, J. Bacteriol. 176:1443-1450, 1994. We report here that the glyceraldehyde-3-phosphate dehydrogenase, one of the key enzymes of the glycolytic pathway, is inhibited by high NADH/NAD ratios. Partial substitution of glucose by pyruvate while maintaining glycerol concentration at a constant level allowed a higher consumption of glycerol in steady-state continuous cultures. However, glycerol-sufficient cultures had a constant flux through the glyceraldehyde-3-phosphate dehydrogenase and a constant NADH/NAD ratio. A high substitution of glucose by pyruvate [P/(G + P) value of 0.67 g/g] provided a carbon-limited culture with butanol and butyrate as the major end products. In this alcohologenic culture, the induction of the NADH-dependent butyraldehyde and the ferredoxin-NAD(P) reductases and the higher expression of alcohol dehydrogenases were related to a high NADH/NAD ratio and a low intracellular ATP concentration. In three different steady-state cultures, the in vitro phosphotransbutyrylase and butyrate-kinase activities decreased with the intracellular ATP concentration, suggesting a transcriptional regulation of these two genes, which are arranged in an operon (K. A. Walter, R V. Nair, R. V. Carry, G. N. Bennett, and E. T. Papoutsakis, Gene 134:107-111, 1993).Clostridium acetobutylicum, a strictly anaerobic spore-forming bacterium, usually shows a biphasic batch fermentation pattern. After producing acetate and butyrate during exponential growth, the organism switches to the formation of acetone, butanol, and ethanol shortly before entering the stationary phase. The mechanisms responsible for the onset of solventogenesis are currently the focus of much scientific research.In batch cultures, the initiation and sustained production of solvents are associated with a low extracellular and intracellular pH and a high undissociated butyric acid concentration (7,15,20). In continuous culture, ATP and NAD(P)H availabilities appear to play a key role in product selectivity. High ATP concentration related to low ATP demand or high efficiency of ATP generation would lead to enhanced solvent production (i) for glucose-sufficient cultures at a low pH with biomass recycling (12, 13); (ii) for iron-, nitrogen-, or phosphate-limited cultures (1, 2, 19); and (iii) during shifts induced on phosphatelimited cultures by lowering the pH or adding organic acids (6). Ethanol and butanol productions were associated with increased availability of reducing power (i) when the in vivo activity of the hydrogenase was decreased by CO gassing (5, 10, 13, 14) or by adding methyl viologen (6); (ii) during a shift in solvent production induced by lowering the pH when acetyl coenzyme A (CoA) was first converted to acetone (a pathway consuming no reducing energy), creating a redox imbalance (6); (iii) when an NADH pressure was ...

show abstract

“…This assumption was also supported by the data obtained in our separated experiment, which show that by using the very small working volume (10 mL) the consumed xylans after 24 h fermentation was much lower than that in the experiment using a higher working volume (250 mL) (Ambarsari et al 2010). The second phase of bacterial growth was then suggested to be caused by the concurrent consumption of total sugar and acids in xylans fermentation as happened previously in another study (Monot et al 1984).…”

Section: Discussionmentioning

confidence: 68%

Production of Acetone, Butanol and Ethanol as Bioenergy Source Materials by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) using Different Substrates

Ambarsari¹,

Sonomoto

2013

Microbiol Indones

View full text Add to dashboard Cite

The cost of raw materials has been known to be the major limitation on the economic feasibility of acetone-butanol-ethanol (ABE) production. About 60-70% of the total ABE production cost is the cost for substrates (Madihah et al. 2001). Therefore, many researches have been conducted to find the most economical substrates for ABE production, for examples those who used simple sugars such as glucose, lactose, galactose, and xylose (Shinto et al.2008;Keis et al. 2001;Bahl et al. 1986), or moreIn the effort of developing bioenergy source materials, a laboratorium study was performed to investigate the effects of substrate types and concentrations on the production of acetone-butanol-ethanol (ABE) from various substrates by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) in defined TYA (Tryptone-Yeast extract-Acetate) media. The results demonstrated that the ABE ratios produced by the strain N1-4 were greatly influenced by the types of substrate and the concentrations being used. It was also shown that fermentation of disaccharides (cellobiose and dextrin) by the strain N1-4 could give relatively as high butanol and ABE yields as glucose fermentation after 24 h fermentation time. The strain N1-4 was also found to be able to ferment xylans from birchwood sources producing a relatively high ABE concentration, especially at a prolonged incubation time (after 48 h incubation period). A subsequent experiment using several different concentrations of glucose or cellobiose revealed that the higher the concentration of the substrate being used, then the higher the total ABE concentration or productivity could be obtained but not necessarily in the same increasing ratio. To the best of our knowledge, there was no other previous study about the effect of substrate type and concentration on the ABE ratio by C. saccharoperbutylacetonicum N1-4 (ATCC 13564) using various substrates in defined TYA media, specifically by using xylans and dextrin substrates.Key words: ABE ratio, acetone-butanol-ethanol fermentation, biomass substrate effect, Clostridium saccharoperbutylacetonicum N1-4Dalam rangka mendapatkan bahan baku bioenergi, sebuah studi laboratorium dilakukan untuk mengetahui pengaruh dari jenis dan konsentrasi substrat biomasa terhadap proses fermentasi langsung yang menghasilkan aseton, butanol, dan etanol oleh bakteri Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) dalam media TYA (Tryptone-Yeast extract-Acetate) yang terdefinisi. Hasil penelitian menunjukkan bahwa rasio dari aceton:butanol:etanol (rasio ABE) ternyata sangat dipengaruhi oleh jenis substrat biomass dan konsentrasi yang dipergunakan dalam proses fermentasinya. Data menunjukkan bahwa dengan menggunakan substrat disakarida (yang diwakili oleh dextrin dan cellobiose), strain N1-4 mampu menghasilkan ABE dengan yield yang relatif sama tinggi dengan menggunakan glukosa setelah masa fermentasi 24 jam. Strain N1-4 ternyata juga mampu memproduksi ABE dengan konsentrasi yang cukup tinggi dengan menggunakan substrat xylan yang diekstraksi dari kayu, wa...

show abstract

Influence of pH and undissociated butyric acid on the production of acetone and butanol in batch cultures of Clostridium acetobutylicum

Cited by 200 publications

References 12 publications

Regulation of carbon and electron flow in Clostridium acetobutylicum grown in chemostat culture at neutral pH on mixtures of glucose and glycerol

Regulation of carbon and electron flow in Clostridium acetobutylicum grown in chemostat culture at neutral pH on mixtures of glucose and glycerol

Regulation of Clostridium acetobutylicum metabolism as revealed by mixed-substrate steady-state continuous cultures: role of NADH/NAD ratio and ATP pool

Production of Acetone, Butanol and Ethanol as Bioenergy Source Materials by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) using Different Substrates

Contact Info

Product

Resources

About