| abstract |
FIELD: biotechnology, microbiology. SUBSTANCE: invention relates to biosynthesis of human cytokines (tumor necrosis alpha- and beta-factor, granulocyte and granulocyte-macrophage colony-stimulating factors) by recombinant strains of E. coli SG20050/pTNF311Δ, E. coli SG20050pLT21, E. coli SG20050/pGGG8 and E. coli SG20050/p280GM. For preparing inoculum with high content of plasmid-containing cells inoculate is treated with ampicillin in concentration 400-500 mcg/ml for 2-3 h. Ampicillin in concentration 100 mcg/ml is added to medium in the process of fermentation. Ampicillin is added in each 1-2 h of culture growth. EFFECT: decreased segregation nonstability of recombinant strains, increased content of end proteins in biomasses. 6 cl, 1 dwg, 6 tbl, 5 ex |