Microbial transformation of epoxides

Swaving, Jelto; Bont, J.A.M. de

doi:10.1016/s0141-0229(97)00097-5

Cited by 64 publications

(31 citation statements)

References 87 publications

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“…In general the epoxides react readily with a great number of cell compounds, including proteins and DNA. Therefore, they have to be rapidly detoxified and eliminated by specific hydrolases or glutathione transferases (Swaving & de Bont, 1998 ;Leak et al, 1992). However, the dynamics of stress exposure, cell recovery and lipid extraction under these experimental conditions could have prevented the elimination of vernolic acid.…”

Section: Discussionmentioning

confidence: 99%

Alteration in cellular fatty acid composition as a response to salt, acid, oxidative and thermal stresses in Lactobacillus helveticus

2001

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The fundamental question in this study is concerned with whether the increase of unsaturated fatty acids in the cell membrane is a general response of certain thermotolerant strains or species when exposed to superoptimal temperatures, and in combination with other stresses, especially oxidative stress. A strain of Lactobacillus helveticus, a species widely used as a starter in the dairy industry and able to tolerate high temperature and NaCl concentrations as well as acidic conditions, was chosen for this study. Cells of strain CNBL 1156, grown in its natural medium (i.e. milk whey), were exposed for 100 min to sublethal combinations of temperature, NaCl, H 2 O 2 and pH, modulated according to a Central Composite Design. The fatty acid composition of cell lipid extract was identified by GC/MS. Polynomial equations, able to describe the individual interactive and quadratic effects of the independent variables on cell fatty acid composition, were obtained. The results and the mathematical models relative to the individual fatty acids indirectly suggest that desaturase activation or hyperinduction play an important role in the response to heat stress. In fact, the relative proportions of oleic, linoleic and palmitic acids increased with temperature in a range between 38 and 54 SC. The fatty acid profiles included vernolic acid (up to 37 % of total fatty acids), an epoxide of linoleic acid not previously reported in microbial cells. In particular, this epoxide was present in cells exposed to low pH in combination with high temperatures and oxidative stress. In conclusion, these results provide experimental support to the hypothesis that the increase of an oxygen-consuming desaturase system, with a consequent increase in fatty acid desaturation, is a cellular response to environmental stresses able to protect the cells of this anaerobic micro-organism from toxic oxygen species and high temperatures.

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Section: Discussionmentioning

confidence: 99%

Alteration in cellular fatty acid composition as a response to salt, acid, oxidative and thermal stresses in Lactobacillus helveticus

2001

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“…Further, it has proven difficult to reach satisfying specific activities and consequently, total volumetric productivities (Onumonu et al, 1994), although very impressive rates of up to 500 mol и min −1 и g (cell dry weight) −1 (U и (g cdw) −1 ) have been reported in isolated cases for short conversion times in the range of minutes for the formation of racemic propene oxide (Stanley and Dalton, 1992). Finally, product catabolism by the cell can reduce product yields (de Bont et al, 1983;Habets-Crützen et al, 1984;Hou et al, 1983;Onumonu et al, 1994;Swaving and de Bont, 1998).…”

Section: Introductionmentioning

confidence: 99%

Production of enantiopure styrene oxide by recombinantEscherichia coli synthesizing a two-component styrene monooxygenase

Panke

Wubbolts²,

Schmid³

et al. 2000

Biotechnol. Bioeng.

128

122

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“…Various chemocatalytic and biocatalytic methods have been developed for preparing chiral epoxides (Tokunaga et al, 1997, Swaving and De Bont, 1998, Spelberg et al, 2004. Among the biocatalytic routes, there are several main methods to produce the enantiopure ECH.…”

Section: Introductionmentioning

confidence: 99%

Kinetic investigation on enantioselective hydrolytic resolution of epichlorohydrin by crude epoxide hydrolase from domestic duck liver

Ling¹,

Wang³

et al. 2011

Afr. J. Biotechnol.

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Enantiopure epichlorohydrin is a valuable epoxide intermediate for preparing optically active pharmaceuticals. In this study, a novel epoxide hydrolase prepared from domestic duck liver was used as biocatalyst for producing (S) -epichlorohydrin from its racemates. To characterize the biocatalytic profiles of crude epoxide hydrolase, some effect factors were investigated. The crude epoxide hydrolase has an apparent optimal pH of 8.0 and an optimal temperature of 35°C. Fe 2+ and Mn 2+ both enhanced the activity of epoxide hydrolase to different degrees. The results of kinetic study revealed that a significant inhibition phenomenon is observed in this reaction process. The apparent kinetic parameters (viz., V max and K m ) and apparent substrate inhibition parameter K is were calculated with linear fitting. The developed production process indicates that the novel epoxide hydrolase from domestic duck liver is a highly efficient biocatalyst for preparing enantiopure epichlorohydrin.

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Microbial transformation of epoxides

Cited by 64 publications

References 87 publications

Alteration in cellular fatty acid composition as a response to salt, acid, oxidative and thermal stresses in Lactobacillus helveticus

Alteration in cellular fatty acid composition as a response to salt, acid, oxidative and thermal stresses in Lactobacillus helveticus

Production of enantiopure styrene oxide by recombinantEscherichia coli synthesizing a two-component styrene monooxygenase

Kinetic investigation on enantioselective hydrolytic resolution of epichlorohydrin by crude epoxide hydrolase from domestic duck liver

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