Enterobacter cloacae

Enterobacter aerogenes Enterobacter cloacae Enterobacteriaceae Enterobacter ridant Enterobactin Enterococcus faecalis Enterohepatitis Enteroviruses... 

Amino-2 -deoxypurines. 2 -AmiQo-2 -deoxyadenosine (15) is a naturally occurring A[-nucleoside isolated from A.ctinomadura that shows antknycoplasmal activity (1,4). Adenosine is the direct precursor for its biosynthesis (30). 2 -Arnino-2 -deoxyguanosine (16), isolated from a strain of Enterobacter cloacae (1,4), shows the growth of HeLa S3 cells and Sarcoma 180 in vivo and has been tested for antibacterial activity. 

I Citrobacter freundii Klebsiella pneumoniae Enterobacter cloacae Yersinia enterocolitica... 

Figure 17.14 Model of evolved mutant from cephalosphorinase shuffling. The sequence of the most active cephalosporinase mutant was modeled using the crystal structure of the class C cephalosporinase from Enterobacter cloacae. The mutant and wild-type proteins were 63% identical. This chimeric protein contained portions from three of the starting genes, including Enterobacter (blue), Klebsiella (yellow), and Citrobacter (green), as well as 33 point mutations (red). (Courtesy of A. Crameri.)...

Benzyl- and Phenoxymethylpenicillins, Ampidllin, Carbenicillin Cephalosporin C Cephaloglycine, Cephaloridine, Cephalothin Hydrolysis Corresponding p-lactam ring cleavage products Escherichia coli Streptomyces aibus Pseudomonas aeruginosa Enterobacter cloacae Streptomyces sp. 

Studies on 4-hydroxybenzoate decarboxylase and 3,4-hydroxybenzoate decarboxylase have been restricted to obligate anaerobic bacteria, C. hydroxy-benzoicum Aside from the obligate anaerobic microorganism, C. hydroxy-benzoicum, very recently facultative anaerobic bacteria, Enterobacter cloacae strains exhibiting high 4-hydroxybenzoate decarboxylase or... 

The occurrence of 3,4-dihydroxybenzoate decarboxylase was also found widely in facultative anaerobes. Among them, Enterobacter cloacae P241 showed the highest activity of 3,4-hydroxybenzoate decarboxylase, and the activity of the cell-free extract of E. cloacae P241 was determined to be 0.629 p.mol min (mg protein) at 30°C, which was more than that of C. hydroxybenzoicum, 0.11 (xmol min mg protein)" at 25°C. The E. cloacae P241 enzyme has a molecular mass of 334 kDa and consists of six identical 50 kDa subunits. The value for 3,4-dihydroxybenzoate was 177 p.M. The enzyme is also characteristic of its narrow substrate specificity and does not act on 4-hydroxybenzoate and other benzoate derivatives. The properties of E. cloacae P241 3,4-hydroxybenzoate decarboxylase were similar to those of C. hydroxybenzoicum in optimum temperature and pH, oxygen sensitivity, and substrate specificity. 

The decarboxylation of 4-hydroxycinnamic acid to 4-hydroxystyrene, and of fernlic acid (3-methoxy-4-hydroxycinnamic acid) to 4-vinylgnaiacol by several strains of Haf-nia alvei and H. protea, and by single strains of Enterobacter cloacae and K. aerogenes (Fignre 2.7d) (Findsay and Priest 1975). The decarboxylase has been pnrihed from Bacillus pumilis (Degrassi et al. 1995). 

FIGURE 2.8 Metabolism of ferulic acid by Enterobacter cloacae. 

French CE, S Nicklin, NC Bruce (1996) Sequence and properties of pentaerythritol tetranitrate reductase from Enterobacter cloacae PB 2. J Bacteriol 178 6623-6627. 

Ridley H, CA Watts, DJ Richardson, CS Butler (2006) Resolution of distinct membrane-bound enzymes from Enterobacter cloacae SKLDla-1 that are responsible for selective reduction of nitrate and selenate anions. Appl Environ Microbiol 12 5173-5180. 

A membrane-bound chromate reductase has been purified from Enterobacter cloacae (Wang et al. 1990). 

The selenate reductase from Enterobacter cloacae SLDla-1 functions only under aerobic conditions, and is not able to serve as an electron acceptor for anaerobic growth, in contrast to the periplasmic enzyme from Thauera selenatis (Schroder et al. 1997). In E. cloacae there are separate nitrate and selenate reductases, both of which are membrane-bound. The selenate reductase is able to reduce chlorate and bromate though not nitrate, contains Mo, heme and nonheme iron, and consists of three subunits in an a3p3y3 configuration. 

Bryant C, L Hubbard, WD McFlroy (1991) Cloning, nucleotide sequence, and expression of nitroreductase gene from Enterobacter cloacae. J Biol Chem 266 4126-4130. 

Bryant C, M DeLuca (1991) Purification and characterization of an oxygen-insensitive N AD(P)H nitroreductase from Enterobacter cloacae. J Biol Chem 266 4119-4125. 

Wang P, T Mori, K Toda, H Ohtake (1990) Membrane-associated chromate reductase activity from Enterobacter cloacae. J Bacterial 172 1670-1672. 

Although reduction of chromate Cr to Cr has been observed in a number of bacteria, these are not necessarily associated with chromate resistance. For example, reduction of chromate has been observed with cytochrome Cj in Desulfovibrio vulgaris (Lovley and Phillips 1994), soluble chromate reductase has been purified from Pseudomonas putida (Park et al. 2000), and a membrane-bound reductase has been purified from Enterobacter cloacae (Wang et al. 1990). The flavoprotein reductases from Pseudomonas putida (ChrR) and Escherichia coli (YieF) have been purified and can reduce Cr(VI) to Cr(III) (Ackerley et al. 2004). Whereas ChrR generated a semi-quinone and reactive oxygen species, YieR yielded no semiquinone, and is apparently an obligate four-electron reductant. It could therefore present a suitable enzyme for bioremediation. 

Losi ME, WT Frankenberger (1997) Reduction of selenium oxyanions by Enterobacter cloacae SLDla-1 isolation and growth of the bacterium and its expulsion of selenium particles. Appl Environ Microbiol 63 3079-3084. 

The chlorate reductase has been characterized in strain GR-1 where it was found in the periplasm, is oxygen-sensitive, and contains molybdenum, and both [3Fe-4S] and [4Fe-4S] clusters (Kengen et al. 1999). The arsenate reductase from Chrysiogenes arsenatis contains Mo, Fe, and acid-labile S (Krafft and Macy 1998), and the reductase from Thauera selenatis that is specific for selenate, is located in the periplasmic space, and contains Mo, Fe, acid-labile S, and cytochrome b (Schroeder et al. 1997). In contrast, the membrane-bound selenate reductase from Enterobacter cloacae SLDla-1 that cannot function as an electron acceptor under anaerobic conditions contains Mo and Fe and is distinct from nitrate reductase (Ridley et al. 2006). 

French CE, S Nicklin, NC Brnce (1998) Aerobic degradation of 2,4,6-trinitrotolnene by Enterobacter cloacae PB2, and by pentaerythritol tetranitrate rednctase. Appl Environ Microbiol 64 2864-2868. 

Khan H, T Barna, RJ Harris, NC Bruce, I Barsukov, AW Munro, PCE Moody, NS Scrutton (2004) Atomic resolution structures and solution behavior of enzyme-substrate complexes of Enterobacter cloacae PB2 pentaerythritol tetranitrate reductase. J Biol Chem 279 30563-30572. 

The biotransformation of gylcerol trinitrate by strains of Bacillus thuringiensis/cereus or Enterobacter agglomerans (Meng et al. 1995), by strains of Pseudomonas sp., and some Entero-bacteriaceae (Blehert et al. 1997) involves the expected successive loss of nitrite with the formation of glycerol. The biotransformation of pentaerythritol tetranitrate by Enterobacter cloacae proceeds comparably with metabolism of two hydroxymethyl groups produced by loss of nitrite to the aldehyde (Binks et al. 1996). 

The third study has employed 4,6-dinitrobenzofuroxan and as metabolic systems the one-electron reductants NADPHxytochrome P450 reductase and ferredoxin NADP(+) reductase and the two-electron reductants DT-diaphorase and Enterobacter cloacae nitroreductase [239]. The compound is activated either by DT-diaphorase or nitroreductase. 

Figure 6.1 Sections (mlz 5000-10,000) from unpublished spectra—standard (a) and blind-coded (b)—obtained from Enterobacter cloaca from work reported in Holland et al.17 showing the very low mass resolution, additional peaks, and three consistent signals used to identify this organism in the first reported whole-cell MALDI experiments in 1996.

Figure 14.1 MALDI MS of Enterobacter cloacae and Proteus mirabilis.

Dungan R.S., Frankenberger W.T. Jr. Factors affecting the volatilization of dimethylselenide by enterobacter cloacae SLDla-1. Soil Biol Biochem 2000 1353-1358. 

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