Acetobacterium

The fermentative fixing of CO2 and water to acetic acid by a species of acetobacterium has been patented acetyl coen2yme A is the primary reduction product (62). Different species of clostridia have also been used. Pseudomonads (63) have been patented for the fermentation of certain compounds and their derivatives, eg, methyl formate. These methods have been reviewed (64). The manufacture of acetic acid from CO2 and its dewatering and refining to glacial acid has been discussed (65,66). 

Another example for the use of hydrogen as reductant is observed in the reduction of imine [5b]. New imine reductase activity has been discovered in the anaerobic bacterium Acetobacterium woodii by screening a dynamic combinatorial library of virtual imine substrates, using a biphasic water-tetradecane solvent system. 

Tschech A, N Pfennig (1984) Growth yield increase linked to caffeate reduction in Acetobacterium woodii. 

Eichler B, B Schink (1984) Oxidation of primary aliphatic alcohols by Acetobacterium carbinolicum sp. nov., a homoacetogenic anaerobe. Arch Microbiol 140 147-152. 

The anaerobic methylotrophic homoacetogen Acetobacterium dehalogenans is able to grow with methyl chloride and COj, and uses a pathway comparable to that noted above for the aerobic... 

FIGURE 7.59 Degradation of methyl chloride hy Acetobacterium halogenans. 

Tetrachloroethene can be dechlorinated to trichloroethene as the sole prodnct by the homoacetogen Sporomusa ovata nsing methanol as the electron donor, and cell extracts of other homoacetogens inclnding Clostridiumformicoaceticum and Acetobacterium woodii were able to carry this ont nsing CO as electron donor (Terzenbach and Blant 1994). 

Cultures of a number of anaerobic bacteria are able to dechlorinate tetrachloromethane and Acetobacterium woodii formed dichloromethane as the final chlorinated metabolite by successive dechlorination, although CO2 was also produced by an unknown mechanism (Egli et al. 1988). 

Egli C, T Tschan, R Scholtz, AM Cook, T Leisinger (1988) Transformation of tetrachloromethane to dichloro-methane and carbon dioxide by Acetobacterium woodii. Appl Environ Microbiol 54 2819-2824. 

Hasham SA, DL Freedman (1999) Enhanced biotransformation of carbon tetrachloride by Acetobacterium woodii upon addition of hydroxycobalamin and fructose. Appl Environ Microbiol 65 4537-4542. 

Kaufmann F, G Wohlfarth, G Diekert (1998) 0-demethylase from Acetobacterium dehalogenans. Substrate specificity and function of the participating proteins. Eur J Biochem 253 706-711. 

Bache R, N Pfennig (1981) Selective isolation of Acetobacterium woodii on methoxylated aromatic acids and determination of growth yields. Arch Microbiol 130 255-261. 

Schramm E, B Schink (1991) Ether-cleaving enzyme and diol dehydratase involved in anaerobic polyethylene glycol degradation by a new Acetobacterium sp. Biodegradation 2 71-79. 

Krumholz LR, Harris SH, Tay ST, Suflita JM. 1999. Characterization of two subsurface H2-utilizing bacteria, Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov., and their ecological roles. Appl Environ Microbiol 65 2300-6. 

Muller V, Aufurth S, Rahlfs S. 2001. The Na -cycle in Acetobacterium woodii identification and characterization of a Na -translocating FiFo-ATPase with a mixed oligomer of 8 and 16-kDa proteolipids. Biochim Biophys Acta 1505 108-20. 

Aufurth S, Schagger H, Muller V. 2000. Identification of subunits a, b, and cl from Acetobacterium woodii Na -FiFo-ATPase. Subunits cl, c2, and c3 constitute a mixed c-oligomer. J Biol Chem 275 33297-301. 

Heise R, Muller V, Gottschalk G. 1992. Presence of a Na -translocating ATPase in membrane vesicles of the homoacetogenic ha.cXermm Acetobacterium woodii. Eur J Biochem 206 553-7. 

Redlinger J, Muller V. 1994. Purification of ATP synthase from Acetobacterium woodii and identification as a Na -translocating FiFq type enzyme. Fur J Biochem 223 275-83. 

Kaufmann, F., Wohlfarth, G., and Diekert, G., 1998, O-Demethylase from Acetobacterium dehalogenans. Cloning, sequencing, and active expression of the gene encoding the corri-noid protein. Eur. J. Biochem. 257 515n521. 

Ragsdale, S. W., and Ljungdahl, L. G., 1984, Hydrogenase from Acetobacterium woodii. Arch. Microbiol. 139 3619365. 

The A/iNa formed may be converted via a Na /H antiporter into a AftfT which then drives the synthesis of ATP via a DCCD-sensitive H -translocating ATP synthase. This ATP formation explains net ATP synthesis coupled to acetate formation from H2/CO2 [192,195,199], Alternatively, A/lNa" could drive ATP synthesis directly via Na "-translocating ATP synthase. A Na -stimulated ATP-synthase activity has recently been reported for Acetobacterium woodii [200]. 

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