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EP0195304A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Stabilization of intracellular enzymes

Assignee: Dow Chemical Co
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Filing: 1986-03-04
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Granted: —
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Expires: 2006-03-04
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Abstract

Abstract @ The subject invention concerns a process for stabilizing intact or ruptured microbial cells having active enzymes associated therewith. Specifically exemplified is a process for stabilizing glucose isomerase producing cells of a microorganism belonging to the genus Ampullariella. In the invention process the whole or ruptured microbial cells are contacted with a partially modified cationic polyelectrolyte, e.g., a partially modified polyamine, to stabilize and flocculate the cells. It is critical that the polyelectrolyte be partially modified; a fully modified or non-modified polyelectrolyte will not give the surprising beneficial results of the invention process. The flocculated cells are further stabilized by encapsulation with a partially modified cationic polyelectrolyte. The encapsulation can be done prior to or after the flocculated cells are cross-linked. The net effect is manifested by a dramatic increase in the half-life of the enzyme, thus. leading to a more effective use of the immobilized enzyme.

Inventors

  • 👤 Roberta C. Cheng
  • 👤 Karen M. Mccoy
  • 👤 Robert A. Houtchens
  • 👤 Norman G. Moll

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 15:22
CPC Classifications
C; C12; C12P; C12P19/00; C12P19/24; C12N; C12N1/00; C12N1/04; C12N11/00; C12N11/02; C12N11/04; C12N9/00; C12N9/96

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 28 words
A process for stabilizing and flocculating intact or ruptured microbial cells having active enzymes associated therewith which comprises contacting the microbial cells with a partially modified cationic polyelectrolyte.
Claim 2
Dependent Claim 28 words
A process for stabilizing and flocculating intact or ruptured microbial cells having active enzymes associated therewith which comprises contacting the microbial cells with a partially modified cationic polyelectrolyte.
Claim 3
Dependent Claim 25 words
Process of Claim 1 which comprises (1) encapsulating the flocculated microbial cells with a partially modified cationic polyelectrolyte, and (2) cross-linking the encapsulated microbial cells.
Claim 4
Dependent Claim 16 words
Process of Claim 2 wherein the flocculated microbial cells are cross-linked both before and after encapsulating.
Claim 5
Dependent Claim 18 words
The process of any one of Claims 1 to 3 wherein the microbial cells are glucose isomerase--producing cells.
Claim 6
Dependent Claim 21 words
The process of any one of Claims 1 to 4 wherein the partially modified cationic polyelectrolyte is a partially modified polyamine.
Claim 7
Dependent Claim 52 words
The process of any one of Claims 1 to 5 wherein the partially modified cationic polyelectrolyte is a partially carboxyalkylated, or partially phosphonoalkylated, cationic polyelectrolyte wherein the alkyl is -(CH 2 ) n - wherein n=1-3, or -(CHR)-(CH 2 ) n - wherein R=methyl, ethyl, propyl, or isopropyl, and n=l or 2.
Claim 8
Dependent Claim 15 words
The process of Claim 6 wherein the partially carboxyalkylated cationic polyelectrolyte is partially carboxymethylated polyethyleneimine.
Claim 9
Dependent Claim 42 words
The process of any one of Claims 1 to 7 wherein the modification of the partially modified cationic polyelectrolyte is from 0.1 to 1.0 equivalents of polyelectrolyte during the flocculating step and 0.2 to 1.0 equivalents of polyelectrolyte during the encapsulating steps.
Claim 10
Dependent Claim 27 words
The process of Claim 8 wherein the partially modified cationic polyelectrolyte is polyethyleneimine which is carboxymethylated in the range of 0.25 to 0.5 equivalents of the imine.
Claim 11
Dependent Claim 33 words
A process for preparing D-fructose from D-glucose which comprises contacting D-glucose with glucose isomerase-producing intact or ruptured microbial cells which have been 1) flocculated with a partially modified cationic polyelectrolyte, and (2) cross-linked.
Claim 12
Dependent Claim 33 words
A process for preparing D-fructose from D-glucose which comprises contacting D-glucose with glucose isomerase-producing intact or ruptured microbial cells which have been 1) flocculated with a partially modified cationic polyelectrolyte, and (2) cross-linked.
Claim 13
Dependent Claim 21 words
Process for Claim 10 wherein the microbial cells employed have been encapsulated with a partially modified cationic polyelectrolyte, and agëin cross-linked.

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