Zoogloea ramigera

The 3-ketothiolase has been purified and investigated from several poly(3HB)-synthesizing bacteria including Azotobacter beijerinckii [10], Ral-stonia eutropha [11], Zoogloea ramigera [12], Rhodococcus ruber [13], and Methylobacterium rhodesianum [14]. In R. eutropha the 3-ketothiolase occurs in two different forms, called A and B, which have different substrate specificities [11,15]. In the thiolytic reaction, enzyme A is only active with C4 and C5 3-ketoacyl-CoA whereas the substrate spectrum of enzyme B is much broader, since it is active with C4 to C10 substrates [11]. Enzyme A seems to be the main biosynthetic enzyme acting in the poly(3HB) synthesis pathway, while enzyme B should rather have a catabolic function in fatty-acid metabolism. However, in vitro studies with reconstituted purified enzyme systems have demonstrated that enzyme B can also contribute to poly(3HB) synthesis [15]. 

Masamune, S., Palmer, M.A.J., Gamboni, R., Thompson, S., Davis, J.T., Williams, S.F., Peoples, O.P., Sinskey, A.J., and Walsh, C.T. (1989) Bio-Claisen condensation catalyzed by thiolase from Zoogloea ramigera. Active site cysteine residues. Chemtracts Org. Chem. 2, 247-251. 

Norberg, A. B. and Persson, H. (1984). Accumulation of heavy metals by Zoogloea ramigera, Biotechnol. Bioeng., 26, 239-246. 

Kuhn, S. P. and Pfister, R. M. (1989). Adsorption of mixed metals and cadmium by calcium alginate immobilised Zoogloea ramigera, Appl. Microbiol., 31, 613-618. 

Ethyl (R)-3-hydroxybutanoate (15) of 100% e.e. is prepared by ethanolysis of poly-3-hydroxybutanoate (PHB) (16,1/7). Seebach et al. used PHB generated by Alcaligenes eutrophus (16), while we employed Zoogloea ramigera(15,17). 

Davis JT, Moore RN, Imperiali B, Pratt AJ, Kobayashi K, Masamune S, Sinskey AJ, Walsh CT, Eukni T, Tomita K. Biosynthetic thiolase from zoogloea-ramigera.1. Prehminary characterization and analysis of proton-transfer reaction. J. Biol. Chem. 1987 262 82-89. 

Palmer MAJ, Differding E, Gamboni R, Williams SF, Peoples OP, Walsh CT, Sinskey AJ, Masamune S. Biosynthetic thiolase from zoogloea-ramigera. Evidence for a mechanism involving Cys-378 as the active-site base. J. Biol. Chem. 1991 266 8369-8375. 

Tanaka, T., Hirama, M. Bio-Claisen condensation catalyzed by thiolase from Zoogloea ramigera. Active site cysteine residues. Chemtracts Org. Chem. 1989, 2, 247-251. 

Scheme 9 (a) The general mechanism of decarboxylating and nondecarboxylating Clalsen condensing enzymes, (b) A mechanistic proposal for the thiolase enzyme from Zoogloea ramigera as based on Its determined crystal structure. 

The Poly-3-hydroxybutyrate (P3HB) form of PHB [54, 55, 4, 56, 57] is probably the most common type of polyhydroxyalkanoate which is isolated from Azotobacter chroococcum. Pseudomonas putida. Pseudomonas oleovorans, Alcaligenes eutrophus, Zoogloea ramigera, and Alcaligenes sp. A-04 [ 58, 59, 55,60, 61,62,56]. 

Peoples O.P., Masamune S., Walsh C.T. and Sinskey A.J., 1987, Biosynthetic thiolase from Zoogloea ramigera. III. Isolation and characterization of the structural gene. J. Biol. Chem. 262 97-102. 

Logan, B. E. and Wilkerson, D. B. (1991). Eractal dimensions and porosities of Zoogloea ramigera and Saccharomyces cerevisae aggregates. Biotechnol. Bioeng., 23, 389-396. 

Fractal dimensions of both bacteria and yeast fiocs have also been determined in liquid culture in the laboratory, providing a useful quantification of fluid dynamic environment effects upon microbial aggregates. The bacterium Zoogloea ramigera had a A = 1-69 0.11 (determined from projected area. Section 8.2.4)... 

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