Microbial esterases

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). 

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... 

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

A microbial esterase, Mucor miehei esterase, has been extensively studied for flavor development in cheese and was found to produce flavor notes resembling those of Fontina and Romano cheeses (4). 

Ochratoxin A is a colourless crystalline compound with blue fluorescence under ultraviolet light. It has a weak acidic character, with pfC values of 4.4 (carboxyl group of phenylalanine) and approximately 7.5 (phenolic group). Acid hydrolysis splits ochratoxin A into phenylalanine and ochratoxin alpha, an optically active lactone acid. The lactone ring may be opened by alkali or treatment with some microbial esterases, and this removes toxicity. This reaction is reversible, under acidic conditions (Monad Palmisano, 2004). 

Scheme 2.36 Resolutirai of a-chiral ester using the isoenzyme A-PLE Microbial Esterases...

FIGURE 19.72 Microbial resolution of ( )-isomenthyl acetate (137c-Ac and 137c -Ac) by microbial esterase. (Modi ed from Oritani, T. and Yamashita, K., A nc. Biol. Chem., 37, 1695, 1973b.)... 

Mukai, K., Doi, Y., Sema, Y. and Tomita, K. (1993b) Substrate specificities in hydrolysis of polyhydrox-yalkanoates by microbial esterases, Biotechnol. Lett., 15, 601-604. 

Bertola MA, Quax WJ, Robertson BW, Marx AF, van der Laken CJ (1992) Microbial esterases and process for the preparation of 2-arylpropionic acids. Patent EP 233656-B... 

The hydrolysis of the cellulose acetate could be the result of the presence of moisture in the soil or the result of the action of microbial esterases. Many soil micro-organisms are known to secrete cellulases to digest plant debris in the soil (Siu, 1951). 

Chrost, R. J. Gajewski, A. Siuda, W. Fluorescein-diacetate (FDA) assay for determining microbial esterase activity in lake water. Adv. Limnol. 1999, 54, 167-183. 

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). 

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... 

---