Influence of pH on the expression of a recombinant epoxide hydrolase in Aspergillus niger.

The filamentous fungus Aspergillus niger was investigated in relation to its ability to produce a soluble epoxide hydrolase (EH) (E.C. 3.

Preparative scale Baeyer-Villiger biooxidation at high concentration using recombinant Escherichia coli and in situ substrate feeding and product removal process.

An efficient biocatalytic process based on the use of adsorbent resin (in situ substrate feeding and product removal) makes experiments at high substrate concentration possible by overcoming limitations due to substrate and product inhibition. This process was successfully applied to the preparative scale Baeyer-Villiger biooxidation of (-)-(1S,5R)-bicyclo[3.2.

On the influence of oxygen and cell concentration in an SFPR whole cell biocatalytic Baeyer-Villiger oxidation process.

Efficient whole cell biotransformations, in particular microbial whole cell Baeyer-Villiger oxidation with molecular oxygen, demand comprehension and optimization of the process details involved. Optimal provision of oxygen and control of bioprocess parameters are pivotal for their success. The interrelation of cell density and oxygen supply in an in situ substrate feeding and product removal (SFPR) whole cell Baeyer-Villiger oxidation process was investigated in detail.

Microbial transformations 59: first kilogram scale asymmetric microbial Baeyer-Villiger oxidation with optimized productivity using a resin-based in situ SFPR strategy.

This study is demonstrating the scale up of asymmetric microbial Baeyer-Villiger oxidation of racemic bicyclo[3.2.0]hept-2-en-6-one (1) to the kilogram scale using a 50 L bioreactor.

Microbiological transformations 57. Facile and efficient resin-based in situ SFPR preparative-scale synthesis of an enantiopure "unexpected" lactone regioisomer via a Baeyer-Villiger oxidation process.

[reaction: see text] The microbiological Baeyer-Villiger oxidation of (-)-bicyclo[3.2.0]hept-2-en-6-one allowed exclusive formation of the "unexpected" lactone regioisomer in 84% yield, high chemical purity, and enantiopure form.

Enhancing the enantioselectivity of an epoxide hydrolase by directed evolution.

[reaction: see text] The epoxide hydrolase (EH) from Aspergillus niger, which shows a selectivity factor of only E = 4.6 in the hydrolytic kinetic resolution of glycidyl phenyl ether, has been subjected to directed evolution for the purpose of enhancing enantioselectivity. After only one round of error-prone polymerase chain reaction (epPCR), enantioselectivity was more than doubled (E = 10.

The first fluorogenic assay for detecting a Baeyer-Villigerase activity in microbial cells.

The first fluorogenic assay allowing for detection of microbial enzymes able to perform Baeyer-Villiger oxidation is described. This is based on the use of 4-oxopentyl umbelliferyl ether 1 as a fluorogenic substrate. When Baeyer-Villigerases active against this test ketone are present in the selected whole cells, 1 is transformed into 3-hydroxypropyl umbelliferyl ether 3, which, in a subsequent step, releases the fluorescent product umbelliferone.

Enzymatic transformations. Immobilized A. niger epoxide hydrolase as a novel biocatalytic tool for repeated-batch hydrolytic kinetic resolution of epoxides.

Studies aimed at immobilization of the Aspergillus niger epoxide hydrolase were performed. The use of conventional approaches, i.e.

Towards large-scale synthetic applications of Baeyer-Villiger monooxygenases.

Biocatalysis is coming of age, with an increasing number of reactions being scaled-up and developed. The diversity of reactions is also increasing and oxidation reactions have recently been considered for scale-up to commercial processes. One important chemical conversion, which is difficult to achieve enantio- or enantiotopo- selectively, is the Baeyer-Villiger (BV) oxidation of ketones.

A spectrophotometric assay for measuring and detecting an epoxide hydrolase activity.

In this paper we report the development of a novel and simple spectrophotometric assay which allows one to achieve the continuous, rapid, sensitive, and accurate determination of an epoxide hydrolase activity. This assay is based on the elaboration of a coupled enzymatic/chemical methodology which allows quantification of the enzymatic activity within 3min, and offers good sensitivity of about 10 micro Mmin(-1). Applicability of this test to some other aromatic epoxides has been shown and some limitations have also been explored.