Growth inhibition of DH5α E. coli in M9 minimal media following transformation with the recombinant plasmid pMOB3

Abstract

The DH5 α E. coli strain will proliferate in M9 minimal media supplemented with 0.2% glycerol and thiamine (0.5 µg/ml), however a closely related strain, C584 will not. C584 is a DH5 α derivative which contains the plasmid pMOB3. The purpose of this study was to investigate whether the presence the pMOB3 plasmid or an unidentified difference between chromosomal genotypes was the cause of this growth limitation. To examine this problem, pMOB3 was extracted from C584 and cloned into DH5 α cells that had demonstrated growth in the specified M9-glycerol minimal media. Uptake of the plasmid resulted in loss of the ability of the cells to proliferate in M9-glycerol media. The presence of this plasmid, or specifically its translated protein products, are somehow responsible for the repression and inhibition of a biological pathway or function that is essential for growth under such limited nutrient conditions.