INVESTIGADORES
DIAZ RICCI Juan Carlos
artículos
Título:
Influence of the medium composition and plasmid combination on the growth of recombinant Escherichia coli JM109 and on the production of the lactamase and the fusion protein EcoRI::Spa.
Autor/es:
RHEE, J.L.; BODE, J.; DIAZ RICCI, JUAN C.; POOCK, D; WEIGEL, B; KRETZNER, G.; SCHÜGERL, K
Revista:
JOURNAL OF BIOTECHNOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 1997 vol. 55 p. 69 - 83
ISSN:
0168-1656
Resumen:
Plasmid-free andplasmid-harbouring E. coli JM109 strains were investigated inshaken flasks, stirred tanks in batch and continuous operation. The shakenflask cultivations were performed in M9 minimal medium and in media with variousprotein supplements. The host hardly grows on M9 minimal medium as opposed tothe plasmid-harbouring cells, which grow well on this medium. All of the investigatedcells propagate well on protein-containing media. The influence of thecombinations of repressor plasmid pRK248cI, the protection plasmid EcoR4and the production plasmid pMTC48 were determined on the initial specificgrowth rate of the E. coli JM109 without gene expression, on theyield coefficient of cell growth, acetate concentration and acetate yieldcoefficient in the yeast extract-containing (HM) medium. The influence ofvarious media on the induction of the gene expression were evaluated. Incultivation media with protein supplement, the growth rate and yieldcoefficient increased. The variation of the volumetric and specific B-lactamaseactivities with the cultivation time were determined in a stirred tank reactorin HM medium. With increasing dilution rate the process performance decreased.Simple relationships exist between the substrate uptake rate and the specificgrowth rate of the continuous cultivated cells in M9 and HM media. Theinfluence of the dilution rate on the cell mass concentration, colony formingunits, acetate formation, yield coefficients of growth and acetate formation, substrateuptake rate, CO2 production rate, ammonium formation rate and b-lactamase activityin M9 and HM media were determined as well. Carbon balances of the batch andcontinuous cultivations indicated high carbon recoveries. On account of the highergrowth rate of plasmid-harbouring cells than that of the plasmid-free cells,the behaviour of the investigated plasmid-free and plasmid-harbouring E.coli JM109 cells deviates from the published properties of otherplasmid-free and plasmid-harbouring E. coli cells.