Pseudomonas aeruginosa sources

Pseudomonas aeruginosa is resistant to many antibacterial agents (Chapters 9,13) and is biochemically very versatile, being able to use many disinfectants as food sources. 

Examples of preservatives are phenylmercuric nitrate or acetate (0.002% w/v), chlorhexidine acetate (0.01 % w/v), thiomersal (0.01 % w/v) and benzalkorrium chloride (0.01 % w/v). Chlorocresol is too toxic to the comeal epithehum, but 8-hydroxyquinoline and thiomersal may be used in specific instances. The principal considerahon in relation to antimicrobial properties is the activity of the bactericide against Pseudomonas aeruginosa, a major source of serious nosocomial eye infections. Although benzal-konium chloride is probably the most active of the recommended preservatives, it cannot always be used because of its incompatibility with many compounds commonly used to treat eye diseases, nor should it be used to preserve eye-drops containing anaesthetics. Since benzalkonium chloride reacts with natural mbber, silicone or butyl rabber teats should be substituted. Since silicone mbber is permeable to water vapour, products should not be stored for more than 3 months after manufacture. As with all mbber components, the mbber teat should be pre-equilibrated with the preservative prior to... 

Wang CL, You SL, Wang SL (2006) Purification and characterization of a novel catechol 1, 2-dioxygenase from Pseudomonas aeruginosa with benzoic acid as a carbon source. Process Biochem 41 1594—1601... 

Table 5.2 contains data about selected copper enzymes from the references noted. It should be understood that enzymes from different sources—that is, azurin from Alcaligenes denitrificans versus Pseudomonas aeruginosa, fungal versus tree laccase, or arthropodan versus molluscan hemocyanin—will differ from each other to various degrees. Azurins have similar tertiary structures—in contrast to arthropodan and molluscan hemocyanins, whose tertiary and quaternary structures show large deviations. Most copper enzymes contain one type of copper center, but laccase, ascorbate oxidase, and ceruloplasmin contain Type I, Type II, and Type III centers. For a more complete and specific listing of copper enzyme properties, see, for instance, the review article by Solomon et al.4... 

It is noteworthy that, in contrast to mammalian systems, the majority of bacterial strains exhibited sufficient activity even when the cells were grown under non-optimized conditions. Since enzyme induction is still a largely empirical task, cells were grown on standard media in the absence of inducers. Furthermore, all attempts to induce epoxide hydrolase activity in Pseudomonas aeruginosa NCIMB 9571 and Pseudomonas oleovorans ATCC 29347 by growing the cells on an alkane (decane) or alkene (1-octene) as the sole carbon source failed [27]. 

Hydride Transfer in NAD+- and NADP -Dependent Enzymes. The transfer of the hydride ion in redox reaction of NAD+- and NADP+-dependent enzymes can occur either to the re- or the xi-face of the pyridine ring of the coenzyme . Such stereochemistry is crucial in the characterization of these enzymes. The same enzymes from different sources can express different stereospecificities. For example, E. coli NAD(P)+ transhydrogenase expressed one form of stereospecificity whereas the Pseudomonas aeruginosa enzyme catalyzes the identical reaction with the other NAD form . 

In some culture conditions, extracellular PolyP was identified as a good source of phosphate (Curless et al, 1996). Using a typical medium in a high-cell-density fermentation of E. coli, 40 % higher cell density was obtained when using PolyP instead of Pi as a phosphate source (Curless et al, 1996). It is probable that the expression of specific porins allows PolyP transfer from the culture medium into the cells. The outer membrane porin PhoE of E. coli (Bauer et al, 1989) and the OprO porin of Pseudomonas aeruginosa (Siehnel et al, 1992 Hancock etal, 1992), induced by phosphate starvation, are examples of proteins which prefere PP and PolyP rather than P . 

Direct electrochemistry has also been used (72-78) to couple the electrode reactions to enzymes for which the redox proteins act as cofactors. In the studies, the chemically reduced or oxidized enzyme was turned over through the use of a protein and its electrode reaction as the source or sink of electrons. In the first report (72, 73) of such application, the electrochemical reduction of horse heart cjd,ochrome c was coupled to the reduction of dioxygen in the presence of Pseudomonas aeruginosa nitrite reductase/cytochrome oxidase via the redox proteins, azurin and cytochrome C551. The system corresponded to an oxygen electrode in which the four-electron reduction of dioxygen was achieved relatively fast at pH 7. 

Ransom et al. 193 cloned the gene for mandelate racemase from Pseudomonas putida in Pseudomonas aeruginosa on the basis of the inability of the latter strain to grow on D-mandelate as a sole carbon source. The amino acid sequence was deduced from the nucleotide sequence, and the predicted molecular mass of the enzyme was 38 750[193. The enzyme is composed of eight identical subunits. The crystal structure of mandelate racemase has been solved and refined at 2.5 A resolution [194. The secondary, tertiary and quaternary structures of mandelate racemase are quite similar to those of muconate lactonizing enzyme 195, 196. Mandelate racemase is composed of two major structural domains and a small C-terminal domain. The N-terminal domain has an a + P structure, and the central domain has an a/p-barrel topology. The C-terminal domain consists of an L-shaped loop. 

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