Bacillus subtilis strain whose extracellular protease activities are reduced, method for obtaining the strain and method for secreting proteins by using the strain
US5084383A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 18, 1990 |
| Grant date | Jan 28, 1992 |
| Priority date | — |
| Expiry date | Jul 18, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC12N15/67
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
Residual extracellular protease activities of a Bacillus subtilis strain can be further reduced by introducing a gene for the stimulation of extracellular protease levels into the genomic DNA of the strain. The resultant strain whose extracellular protease activities are further reduced is transformed with a recombinant plasmid for secretion of a desired protein and the desired protein can be efficiently produced and accumulated in the culture medium in a large amount. The accumulated desired protein can be easily recovered from the culture medium. For example, the accumulation level of human growth hormone secreted by a B. subtilis MT-430 strain carrying recombinant DNA phGH427 for the expression and secretion of human growth hormone can be increased five to tenfold as a result of the above treatment for reduction of the residual extracellular protease activities of the extracellular protease-activity-deficient strain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.