What would happen when one grows a recombinant bacterium in the bioreactor but forget to add antibiotic to the medium in which the recombinant is growing?

Explanation

In the absence of antibiotic there will be no pressure on recomb inants to retain the plasmid (containing the gene of our interest). Sinc e, maintaining a high copy number of plasmids is a metabolic burden to the microbial cells. It will thus tend to loose the plasmid.