Pseudomonas degradation

Endosulfan in aqueous solutions is also expected to undergo biodegradation. In laboratory tests at pH 7 and 20 , Pseudomonas bacteria degraded endosulfan (isomers not specified) under aerobic conditions with a half-life of about 1 week (Greve and Wit 1971). Biotic and abiotic transformations of endosulfan in seawater/sediment microcosms have been reported (Gotham and Bidleman 1989). In biotic tests, half-lives for the a- and P-isomers in seawater-only microcosms (pH 8) were about 5 and 2 days, respectively. In seawater-only microcosms under sterile conditions at a pH of 8 or higher, the half-life for the a-isomer was 2-3 days, whereas the half-life for the p-isomer was 1-2 days. Half-lives were longer in seawater/sediment microcosms, possibly because of the lower pHs (7.3-7.7) in these test systems half-lives were 22 and 8.3 days for the a- and P-isomers, respectively. Endosulfan diol was the main metabolite identified. 

Microbial degradation of validamycin A (8) with a cell suspension of Pseudomonas dentrificans afforded validamine (202) and valienamine (203). Hydrogenolysis of validamycin B, followed by acid hydrolysis, yielded hydroxy validamine (204). Valiolamine (205) was isolated and shown to be a component of validamycin G. ° Biosynthesis of these carba-glycosylamines was extensively studied, and the intramolecular aldol addition of the... 

Phenol is an important intermediate in the anaerobic degradation of many complex and simple aromatic compounds. Tschech and Fuchs proposed that the carboxylation of phenol to 4-hydroxybenzoate is the first step in the degradation of phenol under denitrifying conditions. However, 4-hydroxybenzoate is not detected in the cultures or cell extracts of the denitrifying Pseudomonas species in the presence of CO2 and phenol, but it is detected if phenol is replaced by phenolphosphate. In contrast, 4-hydroxybenzoate is readily detected as an intermediate of phenol degradation in the iron-reducing bacterium GS-15, and 4-hydroxybenzoate may prove to be a common intermediate in the anaerobic transformation. Thus, in anaerobic degradation of phenolic compounds, it has been postulated that carboxylation reactions may play important roles. 

The oxidation by strains of Pseudomonas putida of the methyl group in arenes containing a hydroxyl group in the para position is, however, carried out by a different mechanism. The initial step is dehydrogenation to a quinone methide followed by hydration (hydroxylation) to the benzyl alcohol (Hopper 1976) (Figure 3.7). The reaction with 4-ethylphenol is partially stereospecific (Mclntire et al. 1984), and the enzymes that catalyze the first two steps are flavocytochromes (Mclntire et al. 1985). The role of formal hydroxylation in the degradation of azaarenes is discussed in the section on oxidoreductases (hydroxylases). 

The degradation of 2-hydroxybiphenyl by Pseudomonas azelaica HBPl is initiated by 2-hydroxybiphenyl 3-monooxygenase (Suske et al. 1999). 

The initial hydroxylation in the degradation of some terpenes the ring methylene group of camphor by Pseudomonas putida (Katagiri et al. 1968 Tyson et al. 1972 Koga et al. 1986), and the isopropylidene methyl group of linalool by a strain of P. putida (Ullah et al. 1990). 

The first step in the aerobic degradation of dehydroabietic acid by Pseudomonas abietaniphila strain BMKE-9 is hydroxylation at C-7 (Smith et al. 2004). 

The degradation of isoquinoline by Pseudomonas diminuta strain 7 is initiated by an oxidoreductase that contains [2Fe-2S] centers and the cofactor molybdopterin cytosine dinucleotide (Lehmann et al. 1994). 

Arias-Barrau E, ER Olivera, JM Lnengo, C Eemandez, B Galan, JL Garcia, E Dfaz, B Minambres (2004) The homogentisate pathway a central catabolic pathway involved in the degradation of L-phenylalanine, L-tyrosine, and 3-hydroxyphenylacetate in Pseudomonas putida J Bacterial 186 5062-5077. 

Gao X, CL Tan, CC Yeo, CL P (2005) Molecular and biochemical characterization of the x/ D-encoded 3-hydroxybenzoate 6 hydroxylase involved in the degradation of 2,5-xylenol via the gentisate pathway in Pseudomonas alcaligenes NCIMB 9S61. J Bacterial 187 7696-7702. 

Gieg LM, A Otter, PM Fedorak (1996) Carbazole degradation by Pseudomonas sp. LD2 metabolic characteristics and identification of some metabolites. Environ Sci Technol 30 575-585. 

Kaschabek SR, T Kasberg, D Muller, AE Mars, DB Janssen, W Reineke (1998) Degradation of chloroaromat-ics purification and characterization of a novel type of chlorocatechol 2,3-dioxygenase of Pseudomonas putida GJ31. J Bacterial 180 296-302. 

Renganathan V (1989) Possible involvement of toluene-2,3-dioxygenase in defluorination of 3-fluoro-sub-stituted benzenes by toluene-degrading Pseudomonas sp strain T-12. Appl Environ Microbiol 55 330-334. 

Sander P, R-M Wittich, P Fortnagel, H Wilkes, W Francke (1991) Degradation of 1,2,4-trichloro- and 1,2,4,5-tetrachlorobenzene by Pseudomonas strains. Appl Environ Microbiol 57 1430-1440. 

Schreiber A, M Hellwig, E Dorn, W Reineke, H-J Knackmuss (1980) Critical reactions in fluorobenzoic acid degradation by Pseudomonas sp. B13 Appl Environ Microbiol 39 58-67. 

Shields MS, MJ Reagin, RR Gerger, R Campbell, C Somerville (1995) TOM, a new aromatic degradative plasmid from Burkholderia (Pseudomonas) cepacia G4. Appl Environ Microbiol 61 1352-1356. 

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