Method for increasing viability and transformation efficiency of bacteria during storage at low temperatures
AssigneeInvitrogen Corporation
InventorsFredric R. Bloom, Jonathan Kuo, Jhy-Jhu Lin, Jin Ma
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Abstract
The invention relates to improved E. coli bacteria with enhanced viability at low temperatures, methods for producing improved bacterial strains capable of enhanced viability at low temperatures, and the isolation and use of genetic material capable of enhancing the viability of bacteria at low temperatures. In addition to the enhanced viability at low temperatures, the bacteria may exhibit enhanced transformation efficiencies after storage at low temperatures. As such, the invention may be used for the insertion of exogenous DNA sequences into the bacteria of the invention.
Claims31
A method for enhancing the transformation ability or the viability of a bacterium, said method comprising:
- (a) increasing the unsaturated fatty acid content of the membrane of said bacterium by
- (i) enhancing expression of one or more genes that encode one or more gene products which increase said unsaturated fatty acid content, or
- (ii) genetically selecting for a bacterium having an increased membrane unsaturated fatty acid content, and
- (b) storing said bacterium at a temperature of from about +4° C. to about −80° C.,
- wherein said bacterium, after said storing, exhibits enhanced transformation ability or enhanced viability relative to the transformation ability or viability exhibited by said bacterium prior to increasing its unsaturated fatty acid content.
A method for enhancing the transformation ability or the viability of bacteria, said method comprising:
- (a) increasing the unsaturated fatty acid content of the membrane of said bacteria by
- (i) enhancing expression of one or more genes that encode one or more gene products which increase said unsaturated fatty acid content, or
- (ii) genetically selecting for a bacterium having an increased membrane unsaturated fatty acid content, and
- (b) storing said bacteria at a temperature of from about +4° C. to about −80° C.,
- wherein said bacteria, after said storing, exhibit enhanced transformation ability or enhanced viability relative to the transformation ability or viability exhibited by said bacteria prior to increasing their unsaturated fatty acid content.
A method for obtaining a competent bacterium, said method comprising:
- (a) increasing the unsaturated fatty acid content of the membrane of a bacterium by
- (i) enhancing expression of one or more genes that encode one or more gene products which increase said unsaturated fatty acid content, or
- (ii) genetically selecting for a bacterium having an increased membrane unsaturated fatty acid content;
- and
- (b) making said bacterium competent.
A method for obtaining competent bacteria, said method comprising:
- (a) increasing the unsaturated fatty acid content of the membrane of bacteria by
- (i) enhancing expression of one or more genes that encode one or more gene products which increase said unsaturated fatty acid content, or
- (ii) genetically selecting for bacteria having an increased membrane unsaturated fatty acid content;
- and
- (b) making said bacteria competent.
A competent E. coli possessing a membrane having an increased unsaturated fatty acid content relative to total fatty acid content, wherein said increased unsaturated fatty acid content is caused by the enhanced expression in said E. coli bacterium of one or more genes selected from the group consisting of a fabB gene, a fabF gene, a fabD gene, a fabG gene, a fabA gene, a fabI gene, a fabZ gene, a fadA gene, a fadB gene, a fadE gene, a fadL gene, a fadR gene, a farR gene, and a fatA gene, wherein said competent E. coli exhibits enhanced transformation ability relative to the transformation ability exhibited by said competent E. coli prior to increasing its unsaturated fatty acid content.
A competent E. coli having a membrane with an increased unsaturated fatty acid content, said increase caused by enhancing the expression of one or more genes selected from the group consisting of a fabB gene, a fabF gene, a fabD gene, a fabG gene, a fabA gene, a fabI gene, a fabZ gene, a fadA gene, a fadB gene, a fadE gene, a fadL gene, a fadR gene, a farR gene, and a fatA gene.
Dependencies are inferred from the claim text.