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US4659664A
Expired / Lapsed
US
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Structures containing immobilized microbial cells
Assignee: EXCEL-MINERAL COMPANY Inc
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Filing: 1985-05-10
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Granted: 1987-04-21
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Expires: 2005-05-10
Abstract
Abstract The strength of a bead containing microbial cells within a retaining permeable membrane is improved by incorporating finely divided sericitic clay particles within a hydrocolloid-containing composition used to form the membrane. The hydrocolloid is preferably alginic acid, carboxymethyl cellulose, methylethylcellulose or polyvinyl alcohol in an amount of about 10 to 40% by weight.
Inventors
- 👤 Francis de Buda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:48
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
114 words
In a microbial sphere or bead the exterior of which is formed of an insoluble fluid membrane in which microbial cells are immobilized within the sphere or bead the improvement comprising: said membrane including on a dry weight basis from about 10 to about 40% by weight of a hydrocolloid selected from the group consisting of alginic acid, carboxymethyl cellulose, methylethylcellulose and polyvinyl alcohol, from about 10 to about 40% by weight particles of a -100 mesh standard Tyler screen size of sericitic clay and from about 10 to about 40% by weight of said cells: said sericitic clay being effective to improve the strength characteristics and the resistance to tearing of said membrane.
Claim 2
Dependent Claim
114 words
In a microbial sphere or bead the exterior of which is formed of an insoluble fluid membrane in which microbial cells are immobilized within the sphere or bead the improvement comprising: said membrane including on a dry weight basis from about 10 to about 40% by weight of a hydrocolloid selected from the group consisting of alginic acid, carboxymethyl cellulose, methylethylcellulose and polyvinyl alcohol, from about 10 to about 40% by weight particles of a -100 mesh standard Tyler screen size of sericitic clay and from about 10 to about 40% by weight of said cells: said sericitic clay being effective to improve the strength characteristics and the resistance to tearing of said membrane.
Claim 3
Dependent Claim
16 words
A microbial sphere or bead as claimed in claim 1 wherein: said hydrocolloid is alginic acid.
Claim 4
Dependent Claim
22 words
A microbial sphere or bead as claimed in claim 1 wherein: said particles are of a -325 mesh standard Tyler screen size.
Claim 5
Dependent Claim
16 words
A microbial sphere or bead as claimed in claim 3 wherein: said hydrocolloid is alginic acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-20 | 1990-10-20 | 1991-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-20 | 1994-10-20 | 1995-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-20 | 1998-10-20 | 1999-04-21 | $7700.00 | Window Closed / Lapsed |