Microbial esterase

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. 

J. A. W. Morgan and R. W. Pickup, Activity of microbial peptidases, oxidases and esterases in lake waters of varying trophic status. Can. J. Microbiol. 59 795 (1993). 

Other microbial esterases related to poly(HA) depolymerases ... 

Skipper HD, Gilmour CM, Furtick WR (1967) Microbial versus chemical degradation of atrazine in soils. Soil Sci Soc Am Proc 31 653-656 Sliwinski MK, Goodman RM (2004) Comparison of cienarchaeal consortia inhabiting the rhizosphere of diverse terrestrial plants with those in bulk soil in native environments. Appl Environ Microbiol 70 1821-1826 Stumm W, Morgan JJ (1996). Aquatic chemistry - chemical equlibrium and rates in Natural Waters (3rd edn). Wiley, New York Vega D, Bastide J (2003) Dimethylphthalate hydrolysis by specific microbial esterase. Chemosphere 51 663-668... 

Carboxylesterases and amidases catalyze hydrolysis of carboxy esters and carboxy amides to the corresponding carboxylic acids and alcohols or amines. In general those enzymes capable of catalyzing hydrolysis of carboxy esters are also amidases, and vice versa (110). The role of these enzymes in metabolsim of drugs and insecticides has been reviewed (111, 112). In addition to the interest in mammalian metabolism of drugs and environmental chemicals, microbial esterases have been used for enantioselective hydrolyses (113, 114). 

Metabolic reactions in the liver and the small intestine are well documented [24]. However, only sparse information is available on drug metabolism in the eolon. Drug metabolism in the colon can be brought about by the host enzymes in the epithelial cells or by the microbial enzymes in the gut flora. Metabolie aetivities in the wall of the colon can be attributed to the eytochrome P450, esterases, amidases, and various transferases [25]. Reductive drug metabolism does not appear to be important at this site. 

The metabolism of taxol by Eucalyptus perriniana cell suspension cultures has been recently reported to induce hydrolyses of ester bonds at C-13, C-10 and C-2 [222]. At this moment only very few data have been published about the microbial metabolism of taxoid compounds only site specific hydrolyses of acyl side-chains at C-13 or C-10 by extracellular and intracellular esterases of Nocar-dioides albus SC13,911 and N. luteus SC13,912, respectively, have been reported [223]. On the other hand, Hu et al. [224-226] have recently described some fungal biotransformations of related natural taxane diterpenes extracted from Chinese yews or their cell cultures, in order to obtain new active substances or precursors for hemisynthesis. The taxadiene 145, a 14 -acetylated derivative... 

Kraft mill that had used elemental chlorine historically Microbial community and diatom species in lake sediments sampled from 2-8 cm depths Drop in the ATP content, depressed butyrate-esterase activity indicating toxicity to microorganisms, and reduction in diatom species richness Mika et al., 1999 [31]... 

Attempts to identify extracellular esterase activity in PVA-contaminated sites with proven microbial degradation activity showed no substantial results. The breakdown of the polymer proceeds without concomitantly high extracellular esterase activities [36]. These findings suggest that intracellular esterases are the... 

Ions and channels Acetylcholine esterase Receptors Microbial activity Schizonticlde activity St ffVlatlon and Inhibiting... 

Lactone structures have recently been determined for two microbial metabolites which have antibiotic properties. Antibiotic 1233A (77) was the first /8-lactone to be isolated from a fungus. Esterastin (78), an inhibitor of esterase, is produced by a strain of Streptomyces (71JCS(C)3888, 78MI51300). 

Lawrence, R. C. 1967. Microbial lipases and related esterases. Part II. Estimation of lipase activity. Characterization of lipases. Recent work concerning their effect on dairy products. Dairy Sci. Abstr. 29, 59-70. 

Stereoselective enzymatic hydrolyses of esters represent a further type of biotransformation that has been used for the synthesis of optically active organosilicon compounds. The first example of this particular type of bioconversion is illustrated in Scheme 15. Starting from the racemic (l-acetoxyethyl)silane rac-11, the optically active (l-hydroxyethyl)silane (5)-41 was obtained by a kinetic racemate resolution using porcine liver esterase (PLE E.C. 3.1.1.1) as the biocatalyst7. The silane (5)-41 (isolated with an enantiomeric purity of 60% ee bioconversion not optimized) is the antipode of compound (R)-41 which was obtained by an enantioselective microbial reduction of the acetylsilane 40 (see Scheme 8). 

Nishizawa M, Shimizu M et al (1995) Stereoselective production of (+)-tram-chrysanthemic acid by a microbial esterase cloning, nucleotide sequence, and overexpression of the esterase gene of Arthrobacter globiformis in Escherichia coli. Appl Environ Microbiol 61 3208-3215... 

As increasing research has been carried out with these enzymes, a less empirical approach has been taken as a result of the different substrate profiles that have been compiled for various enzymes in this class. These profiles have been used to construct active site models for such versatile enzymes as the carboxylester hydrolase, pig liver esterase (PLE) (E.C. 3.1.1.1), and the microbial lipases (E.C. 3.1.1.3) from Burkholderia cepacia (formerly Pseudomonas cepacia) lipase (PCL), Candida... 

Huang, H.T., Dooley, J.G. 1976. Enhancement of cheese flavors with microbial esterases. Biotechnol. Bioeng. 18, 909-919. 

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