The Acetone-Butanol-Ethanol ABE Fermentation Process

Maddox IS (1980) Production of n-butanol from whey filtrate using Clostridium acetobutylicum NCIB 2951. Biotechnol Lett 2 493-498 Maddox IS, Steiner E, Hirsch S, Wessner S, Gutierrez NA, Gapes JR, Schuster KG (2000) The cause of acid crash and acidogenic fermentations during the batch acetone-butanol-ethanol (ABE-) fermentation process. J Molec Microbiol Biotechnol 2 95-100... 

Fermentative production of butanol by bacteria is known since the second half of the nineteenth century, and industrial production of butanol, based on fermentation with bacteria Clostridium acetobutylicum, was the second largest fermentative process in the world after ethanol production, during the first half of the twentieth century (Jones and Woods 1986 Durre 2008). In this process, known as the acetone-butanol-ethanol (ABE) fermentation, Clostridia consumes carbohydrates to produce primarily butanol and acetone. 

The industrial production of biobutanol started in 1916 as a fermentation process using bacteria Clostridia acetobutylicum (39). This type of fermentation has been addressed as acetone-butanol-ethanol (ABE) fermentation and is used with molasses and cereal grains. The materials used for ABE fermentation are detailed in Table 11.2. 

The C4-Platform is accessible by fermentation using corn or sugarcane bagasse as feedstock by acetone-butanol or acetone-butanol-ethanol (ABE) fermentation using Clostridium acetobutylicum or Clostridium beijerinckii under anaerobic conditions. This process has been industry standard since decades and produces the three solvents in a ratio ABE = 3 6 1. More recently, microbial fermentation technologies which genetically... 

Yen H-W, Li R-J, Ma T-W. The development process for a continuous acetone—butanol-ethanol (ABE) fermentation by immobilized Clostridium acetobutylicum. J Taiwan Inst Chem Eng November 2011 42(6) 902-7. 

For acetone-butanol-ethanol (ABE) fermentation, the broth contains about 25-35 g/1 of mixed solvents. Butanol concentration is usually less than 20 g/1, which makes its recovery by distillation expensive. This low butanol concentration in the fermentation broth is related to the inability of Clostridium species to produce more butanol due to solvent toxicity (Lee et al., 2008). Metabolic engineering and advanced fermentation techniques are ongoing to enhance the organisms abilities to produce and tolerate higher concentrations of butanol and increase productivity. Several integrated fermentation and recovery processes, such as fed-batch fermentation with pervaporation and continuous fermentation with gas stripping, have been reviewed elsewhere (Lee et al., 2008). 

Microorganisms play a vital role in the production of various biorefinery products. For product formation, a particular microbe has to be maintained under specific process conditions. Butanol production by the clostridial acetone-butanol-ethanol (ABE) fermentation... 

Corn steep liquor (CSL), a byproduct of the com wet-milling process, was used in an immobilized cell continuous biofilm reactor to replace the expensive P2 medium ingredients. The use of CSL resulted in the production of 6.29 g/L of total acetone-butanol-ethanol (ABE) as compared with 6.86 g/L in a control experiment. These studies were performed at a dilution rate of 0.32 hr1. The productivities in the control and CSL experiment were 2.19 and 2.01 g/(Lh), respectively. Although the use of CSL resulted in a 10% decrease in productivity, it is viewed that its application would be economical compared to P2 medium. Hence, CSL may be used to replace the P2 medium. It was also demonstrated that inclusion of butyrate into the feed was beneficial to the butanol fermentation. A control experiment produced 4.77 g/L of total ABE, and the experiment with supplemented sodium butyrate produced 5.70 g/L of total ABE. The butanol concentration increased from 3.14 to 4.04 g/L. Inclusion of acetate in the feed medium of the immobilized cell biofilm reactor was not found to be beneficial for the ABE fermentation, as reported for the batch ABE fermentation. 

The interest in w-butanol as a biofuel has increased in recent years owing to its superior fuel qualities compared to ethanol. These include a higher octane number, lower heat of vaporization, higher energy density (energy/volume), and lower vapor pressure. However, in the traditional ABE (acetone-butanol-ethanol) fermentation process, the concentration of n-butanol coming from the fermenter is lower than that achieved in ethanol fermentation. In addition, acetone and ethanol are also produced. Recent studies to improve yield and increase w-butanol concentration have explored fed-batch systems with stripping, adsorption, liquid-liquid extraction, distillation, and/or pervaporation to recover products. 

Butanol is naturally synthesised by Clostridia in a process called ABE (acetone-butanol-ethanol) fermentation. Butanol pathway, within ABE fermentation, consists of condensing two acetyl-CoA molecules (catalysed by a thiolase) and then reducing the product to butanol (requiring four reductases and one dehydratase). 

So far, the only known natural butanol produced are numerous clostridial species in a process called ABE (acetone-butanol-ethanol) fermentation. Butanol pathway in ABE fermentation consists of condensing two acetyl-CoA molecules (catalysed by a thiolase) and then reducing the product to butanol (requiring four reductases and one dehydratase). Except butanol, acetone and ethanol, Clostridia can also synthesise different chiral substances whose classical chemical synthesis would be challenging (Rogers et al. 1986), and they can degrade several toxic compounds (Francis et al. 1994 Spain 1995). 

ABE (acetone, butanol, and ethanol) fermentation has a long history of commercial use and perhaps the greatest potential for an industrial comeback. Acetone, butanol, and ethanol can all be isolated from this remarkable metabolic system carbon dioxide and hydrogen are additional products. The solvents were used as paint solvents in the expanding automobile industry. Ultimately these processes proved uncompetitive because of poor yields, low product... 

ABE fermentation Another name for the Weizmann process used for the production of acetone, butanol, and ethanol using the acid-resistant bacterium Clostridium acetobutylicum. 

Weizmann process A fermentation process used to produce acetone, butanol, and ethanol using the acid-resistant bacterium Clostridium acetobutylicum. The bacteria derived from soil and cereals is able to convert whey, sugar, and starch. The process was developed by Russian-born chemist Chaim Weizmann (1874-1952) and was used in the UK in the First World War for the production of acetone, which was used in the production of cordite. He became a UK citizen in 1910 and then the first president of Israel in 1949. The process is also known as the ABE fermentation. 

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