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US 6,551,804 B2Granted
Process for preparing 4-cyanopentanoic acid
AssigneeE. I. Du Pont de Nemours and Company
InventorsRobert DiCosimo, Robert D. Fallon, John E. Gavagan
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Abstract
This invention relates to an improved process for preparing a carboxylic acid from the corresponding nitrile using a nitrilase catalyst. More particularly, the instant invention converts 2-methylglutaronitrile to 4-cyanopentanoic acid in aqueous solution using an enzyme catalyst having an nitrilase activity, immobilized in alginate, and crosslinked with glutaraldehyde and polyethylenimine.
Claims8
A method for producing a carboxylic acid comprising:
- a) immobilizing in alginate whole or permeabilized microbial cells having nitrilase activity;
- b) adding, to the immobilized whole or permeabilized microbial cells of step a), a first stabilizer and then a second stabilizer, each in an amount and for a time sufficient to crosslink the immobilized enzyme catalyst, the first stabilizer and the second stabilizer each selected from the group consisting of glutaraldehyde and polyethylenimine, provided the second stabilizer is other than the first stabilizer;
- c) contacting the product of step b) with a nitrile in a suitable aqueous reaction mixture having a NH4+:Ca2+ ratio greater than 20:1 during the course of the reaction;
- d) isolating the carboxylic acid produced in step c) in the form of a salt or an acid;
- and
- e) optionally repeating steps c) and d).
3 more elements
A method for producing 4-cyanopentanoic acid comprising:
- (a) immobilizing in calcium alginate an enzyme catalyst in the form of whole cells or permeabilized microbial cells selected from the group consisting of Acidovorax facilis 72W (ATCC 55746), Acidovorax facilis 72-PF-15 (ATCC 55747), Acidovorax facilis 72-PF-17 (ATCC 55745), Escherichia coli SS1001 (ATCC PTA-1177), and Escherichia coli SW91 (ATCC PTA-1175);
- (b) adding, to the immobilized enzyme catalyst of step a), a first stabilizer and then a second stabilizer, each in an amount and for a time sufficient to crosslink the immobilized enzyme catalyst, the first stabilizer and the second stabilizer each selected from the group consisting of glutaraldehyde and polyethylenimine, provided the second stabilizer is other than the first stabilizer;
- (c) contacting the product of step b) with 2-methylglutaronitrile in a suitable aqueous reaction mixture having, during the course of the reaction, a NH4+:Ca2+ ratio greater than 20:1;
- (d) isolating 4-cyanopentanoic acid produced in step c) in the form of a salt or an acid;
- and
- (e) optionally repeating steps c) and d).
3 more elements
Dependencies are inferred from the claim text.