37results about How to "Good passage stability" patented technology

The invention discloses streptomyces albidoflavus and application thereof in production of epsilon polylysine, and belongs to the field of microbial fermentation engineering. The Streptomyces albus GS114 provided by the invention can grow on an agar culture medium containing more than 10 [mu] g / ml of one or more of streptomycin, gentamycin and rifamycin, shows very strong antibiotic resistance, can normally grow in a liquid culture medium with a pH value of 2.5-3.0 and can synthesize a large amount of epsilon PL, and after fermentation for 200 h, the Streptomyces albus GS114 can be used as anantibiotic. The concentration of epsilon polylysine in the fermentation liquor is 65.7 g / L, and the yield of epsilon polylysine reaches 80.0 g / L or above after fermentation is conducted for 240 h. Thestrain also has good passage stability, and is an epsilon PL industrial production strain with great potential.

The invention discloses a high-yield penicillin strain, and provides a screening method for the above-mentioned strain and the application of the above-mentioned strain in the production of penicillin, belonging to the technical field of antibiotic production and its application. The bacterial strain of the present invention increases the fermentation unit of penicillin by 13.2%, effectively improves the output of penicillin and reduces production cost, and its screening method comprises the following steps: (A) protoplast preparation; (B) high-energy electron mutagenesis; (C) ) rationalization screening; (D) shake flask screening. The invention provides a screening method for penicillin with strong purpose and high probability of mutant strains and its application.

The invention provides a production strain of L-homoserine, which is characterized in that: it has a single stable chromosome, does not contain plasmid form or other free DNA carriers, and one or more of its chromosomal DNA is related to the synthesis of L-threonine The genes of the patients are knocked out or weakened, and / or mutated to enhance, and / or one or more genes related to the L-homoserine metabolic pathway are integrated on their chromosomal DNA.

The invention discloses a method for simultaneously preparing two kinds of monoclonal antibodies. In the method, the conjugate of 33F type pneumonia polysaccharide and hepatitis B surface protein is used as an antigen to immunize mice, and mouse splenocytes with higher antibody levels after immunization are selected. Fusion with SP2 / 0 myeloma cells, and then specific screening by 33F pneumonia polysaccharide, hepatitis B surface protein, and 33F pneumonia polysaccharide and hepatitis B surface protein conjugates as antigens to obtain hybridoma cells, and at the same time prepare a specific recognition of 33F pneumonia Monoclonal antibodies to polysaccharide and hepatitis B surface protein. The method of the present invention to simultaneously prepare monoclonal cell line cells and specific monoclonal antibodies for polysaccharides and proteins after immunization with pneumonia conjugates using hepatitis B surface protein as a carrier saves workload and improves screening efficiency. At the same time, the present invention The two monoclonal antibodies provided have the advantages of high specificity, high sensitivity and good passage stability.

The invention provides a Vero cell line capable of stably expressing protein P54 of an African swine fever virus. The collection number of the cell line is CGMCC No.14316. The cell line not only can identify a polyclonal antibody of African swine fever, but also can generate specific reaction with positive serum of an African swine fever-infected pig. The monoclonal Vero cell line of an African swine fever P4 antigen can be used for stably expressing the protein P54 of the African swine fever virus, and can be used as a cell model or a virus infection model; the cell transmission stability ishigh, the growing speed is high, and culture conditions are simple; a large number of cell lines can be provided; the cell line has a good application prospect for researches on detection and pathogenesis mechanisms of the African swine fever.