摘要:
This invention involves the production of heteropolysaccharides such as xanthan gum by the continuous fermentation of suitable nutrient media with new degenerative resistant variants of Xanthomanas campestris. Fermentation is conducted in a nitrogen, sulfur or phosphorous limited nutrient medium containing glucose or a minimal medium plus yeast extract and glutamic acid, in a first fermenter to enhance cultural growth. After the limiting growth element (nitrogen, sulfur or phosphorous) has been essentially consumed, the medium is then transferred to a second fermenter and fermentation continued while adding a suitable carbohydrate which the bacteria convert into the heteropolysaccharide product. The process may be modified by carrying out cultural growth and production of the polysaccharide in the same fermenter. The bacteria employed were cultured from a glucose-mineral salts medium fortified with yeast extract or a glucose-defined minimal medium in which ammonium chloride served as the sole assimilable nitrogen source.
摘要:
The present application provides polynucleotides comprising 5′-tails with sequence segments useful for the detection of target nucleic acid sequences, and methods for their use in detecting target nucleic acids. The polynucleotides are used to amplify a subsequence of a target nucleic acid in the presence of one or more ribonucleotides. The ribonucleotides are incorporated into amplification products at regular intervals complementary to the 5′-tail sequence segments. Cleavage of amplification products at the bond immediately 3′ to incorporated ribonucleotides produces detectably distinct fragments indicative of the presence or absence of a target nucleic acid.
摘要:
Method of obtaining N-terminal methionine-free proteins are described. The methods employ a novel enzyme, E. coli methionine aminopeptidase either in vitro or in vivo. For in vivo application, plasmid-borne DNA encoding the peptidase is transformed into a bacterial host which produces the desired protein.
摘要:
Disclosed are mutant DNA polymerases having improved extension rates relative to a corresponding, unmodified polymerase. The mutant polymerases are useful in a variety of disclosed primer extension methods. The mutant polymerases overcome the inhibitory effects of a variety of polymerase and reverse transcriptase inhibitors. Therefore, the mutant polymerases are useful in a variety of disclosed methods in the presence of such inhibitors.
摘要:
Methods for obtaining N-terminal methionine-free proteins involve a novel E. coli methionine amino peptidase. The method is capable of in vitro or in vivo application. For in vivo application, a plasmid-borne DNA encoding the peptide is expressed in a bacterial host.
摘要:
Disclosed are mutant DNA polymerases having improved extension rates relative to a corresponding, unmodified polymerase. The mutant polymerases are useful in a variety of disclosed primer extension methods. The mutant polymerases overcome the inhibitory effects by an intercalating dye. Therefore, the mutant polymerases are useful in a variety of disclosed methods in combination with an intercalating dye. Also disclosed are related compositions, including recombinant nucleic acids, vectors, and host cells, which are useful, e.g., for production of the mutant DNA polymerases.
摘要:
Disclosed are mutant DNA polymerases having improved extension rates relative to a corresponding, unmodified polymerase. The mutant polymerases are useful in a variety of disclosed primer extension methods. The mutant polymerases overcome the inhibitory effects by an intercalating dye. Therefore, the mutant polymerases are useful in a variety of disclosed methods in combination with an intercalating dye. Also disclosed are related compositions, including recombinant nucleic acids, vectors, and host cells, which are useful, e.g., for production of the mutant DNA polymerases.
摘要:
Disclosed are mutant DNA polymerases having improved extension rates relative to a corresponding, unmodified polymerase. The mutant polymerases are useful in a variety of disclosed primer extension methods. Also disclosed are related compositions, including recombinant nucleic acids, vectors, and host cells, which are useful, e.g., for production of the mutant DNA polymerases.
摘要:
Disclosed are mutant DNA polymerases having improved extension rates relative to a corresponding, unmodified polymerase. The mutant polymerases are useful in a variety of disclosed primer extension methods. Also disclosed are related compositions, including recombinant nucleic acids, vectors, and host cells, which are useful, e.g., for production of the mutant DNA polymerases.
摘要:
Methods of obtaining N-terminal methionine-free proteins are described. The methods employ a novel enzyme, E. coli methionine aminopeptidase either in vitro or in vivo. For in vivo application, plasmid-borne DNA encoding the peptidase is transformed into a bacterial host which produces the desired protein.