Clostridium acetobutylicum acetoacetate decarboxylase

Some decarboxylases do form Schiff bases with their substrates, and some are dependent on metal ions.235 The acetone-forming fermentation of Clostridium acetobutylicum requires large amounts of acetoacetate decarboxylase (Eq. 13-44). 

Another example where mechanism and model have been developed is that for the decarboxylation of acetoacetic acid here no coenzyme is required, and the chemistry involves the enzyme itself. The mechanism for the enzymic decarboxylation with crystalline decarboxylase from Clostridium acetobutylicum has been worked out in some detail it is presented below (20, 21). The initial work, carried out in the author s laboratory by G. Hamilton (22) and I. Fridovich (23, 24) proved that the essential intermediate is a ketimine much of the subsequent development of the enzymic system resulted from the researches of W. Tagaki (25). 

Clostridium acetobutylicum Acetone and butanol production Overexpression of acetoacetate decarboxylase (adc) and phosphotransbutyrylase (ptb) by introducing a Bacillus subtilis/C acetobutylicum shutde vector into C. acetobutylicum by an improved electrotransformation protocol, which resulted in acetone and butanol formation 88... 

Ballongue, J., Amine, J, Masion, E., Petitdemange, H. et al. (1985) Induction of acetoacetate decarboxylase in Clostridium acetobutylicum. FEMS Microbiol Lett, 29, 273-277. 

Petersen, D.J. and Bennett, G.N. (1990) Purification of acetoacetate decarboxylase from Clostridium acetobutylicum ATCC 824 and cloning of the acetoacetate decarboxylase gene in Escherichia coli. Appl Environ. Microbiol, 56, 3491-3498. 

Jiang, Y, Xu, C., Dong, E, Yang, Y. et al (2009) Disruption of the acetoacetate decarboxylase gene in solvent-producing Clostridium acetobutylicum increases the butanol ratio. Metah. Eng., 11, 284-291. 

Schiel, B., Bohringer, M., Schaffer, S., and Durre, P. (2003) Identification and characterization of a potential transcriptional regulator of the acetoacetate decarboxylase gene of Clostridium acetobutylicum. Biospektrum Spec. Issue, KB003, 39. 

FIGURE 9.2 Physiology of ABE fermentation metabolism of Clostridium acetobutylicum with the respective enzymes and products. CoA, coenzyme A Ldh, lactate dehydrogenase Pdc, pyruvate decarboxylase Pfor, pyruvate ferredoxin oxidoreductase Fdred, ferredoxin reduced Thl, thiolase Hbd, p-hydroxybutyryl-CoA dehydrogenase Crt, crotonase Bed, butyryl-CoA dehydrogenase Etf, electron transfer flavoprotein Pta, phosphotransacetylase Ack, acetate kinase Ptb, phosphotransbutyrylase Buk, butyrate kinase Ctf A/B, acetoacetyl-CoA acyl-CoA transferase Adc, acetoacetate decarboxylase AdhE, aldehyde/alcohol dehydrogenase Bdh, butanol dehydrogenase. 

Gerischer U, Dii P (1990) Cloning, sequencing, and molecular analysis of the acetoacetate decarboxylase gene r on from Clostridium acetobutylicum. J Bacterid 172 6907-6918... 

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