Microbial peroxidase

Goszczynski S, A Paszczynski, MB Pasti-Grigsby, RL Crawford, DL Crawford (1994) New pathways for degradation of sulfonated azo dyes by microbial peroxidases of Phanerochaete chrysosporium and Streptomyces chromofuscus. J Bacterial YIU. 1339-1347. 

Soil. Propanil degrades in soil forming 3,4-dichloroaniline (Bartha, 1968, 1971 Bartha and Pramer, 1970 Chisaka and Kearney, 1970 Duke et al., 1991) which degrades via microbial peroxidases to 3,3, 4,4 -tetrachlorazobenzene (Bartha and Pramer, 1967 Bartha, 1968 Chisaka and Kearney, 1970), 3,3, 4,4 -tetrachloroazooxybenzene (Bartha and Pramer, 1970), 4 (3,4-dichloroanilo)-3,3, 4,4 -tetrachloroazobenzene (Linke and Bartha, 1970), and l,3-bis(3,4-dichloro-phenyl)triazine (Plimmer et al., 1970), propionic acid, carbon dioxide, and unidentified products (Chisaka and Kearney, 1970). Evidence suggests that 3,3, 4,4 -tetrachloroazobenzene reacted with... 

Holm KA. Automated determination of microbial peroxidase activity in fermentation samples using hydrogen peroxide as the substrate and 2,2 -azino-bis(3-ethylbenzothiazoUne-6-sulfo-nate) as the electron donor in a flow-injection system. Analyst 1995 120 2101-2105. 

Blood False positives may arise from oxidizing contaminants (such as hypochlorite), or microbial peroxidase (e.g., as a result of a urinary tract infection). 

PCDD and PCDF arise, unlike most other organochlorine contaminants, almost exclusively as byproducts of anthropogenic activities. Recent research has also confirmed the formation of trace amounts of PCDD and PCDF in enzymatically catalysed reactions. For example, they may be biosynthesised by microbial peroxidases in sewage sludge contaminated with chlorophenols. The most important primary emission sources were or still are ... 

Microbial transformations of ellipticine (15) and 9-methoxyellipticine (16) were reported by Chien and Rosazza (143, 144). Of 211 cultures screened for their abilities to transform 9-methoxyellipticine (16), several, including Botrytis alii (NRRL 2502), Cunninghamella echinulata (NRRL 1386), C. echinulata (NRRL 3655), and Penicillium brevi-compactum (ATCC 10418), achieved O-demethylation of 16 in good yield (Scheme 9). P. brevi-compactum was used to prepare 9-hydroxyellipticine (22) from the methoxylated precursor, and 150 mg of product was obtained from 400 mg of starting material (37% yield). The structure of the metabolite was confirmed by direct comparison with authentic 9-hydroxyellipticine (143). O-Demethylation is a common microbial metabolic transformation with 16 and many other alkaloids (143). Meunier et al. have also demonstrated that peroxidases catalyze the O-demethylation reaction with 9-methoxyellipticine (145). 

Recent work in our laboratories has confirmed the existence of a similar pathway in the oxidation of vindoline in mammals (777). The availability of compounds such as 59 as analytical standards, along with published mass spectral and NMR spectral properties of this compound, served to facilitate identification of metabolites formed in mammalian liver microsome incubations. Two compounds are produced during incubations with mouse liver microsome preparations 17-deacetylvindoline, and the dihydrovindoline ether dimer 59. Both compounds were isolated and completely characterized by spectral comparison to authentic standards. This work emphasizes the prospective value of microbial and enzymatic transformation studies in predicting pathways of metabolism in mammalian systems. This work would also suggest the involvement of cytochrome P-450 enzyme system(s) in the oxidation process. Whether the first steps involve direct introduction of molecular oxygen at position 3 of vindoline or an initial abstraction of electrons, as in Scheme 15, remains unknown. The establishment of a metabolic pathway in mammals, identical to those found in Strep-tomycetes, with copper oxidases and peroxidases again confirms the prospective value of the microbial models of mammalian metabolism concept. 

Kristensen BK, Bloch H, Rasmussen SK (1999) Barley coleoptile peroxidases. Purification, molecular cloning, and induction by pathogens. Plant Physiol 120 501-512 Kubanek J, Jensen PR, Keifer PA, Sullards MC, Collins DO, Fenical W (2003) Seaweed resistance to microbial attack a targeted chemical defense against marine fungi. Proc Natl Acad Sci USA 100 6916-6921... 

To study the effect of veratryl alcohol, purified lignin peroxidase or unfractionated enzyme preparation was incubated with buffer, pH 3.0 or 5.0. The concentration of veratryl alcohol in the incubation mixture was 0, 10 or 100 mM. Incubation times were 38 days at 20°C and 40 days at 4°C. The protein concentration of purified enzyme was 80/tg/ml and of unfractionated preparation 180 tg/ml. The incubation mixtures were sterile filtered to prevent microbial growth. 

Similarly, catechin polymers formed upon horseradish peroxidase-catalyzed oxidation of catechin or polycondensation of catechin with aldehydes prove much more efficient than catechin (at identical monomer concentration) at inhibiting XO and superoxide formation. A more detailed investigation with the catechin-acetaldehyde polycondensate (which is expected to form in wine because of the microbial oxidation of ethanol to acetaldehyde) shows that inhibition is noncompetitive to xanthine and likely occurs via binding to the FAD or Fe/S redox centers involved in electron transfers from the reduced molybdenum center to dioxygen with simultaneous production of superoxide. 

Scheme 23.16 Microbial pathways from triterpene and tetraterpene (carotenoid) precursors to valuable flavour and fragrance compounds. 1 Carotenoid-cleaving peroxidase-containing supernatant of certain fungal cultures, e.g. Lepista irina 2 Serratia liquefaciens, Botrytis sp.

Hammel, K. E. Moen, M. A. (1991). Depolymerization of a synthetic lignin in vitro by lignin peroxidase. Enzyme Microbial Technology, 13, 15-18. 

Cholesterol assay solution. The stock reagent contains pancreatic cholesterol esterase, microbial cholesterol oxidase, horseradish peroxidase, 4-aminoantipyrine, and phenol. Your instructor will reconstitute the stock reagent by addition of water. 

Add sodium azide (0.02% w/v final concentration) to the serum to prevent microbial growth Thiomersal can be used for inhibition of bacteria in cases where use of sodium azide is not compatible with subsequent application of the serum (e.g., sodium azide is a potent inhibitor of horseradish peroxidase, which is often used in enzymatic detection of antigen-antibody complexes)... 

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