Growth Inhibition of DH5α Escherichia coli on M9 Minimal Media is Linked to Specific Restriction Fragment(s) of pMOB3

Abstract

Escherichia coli strain DH5 α is able to grow on M9 minimal media supplemented with 0.2% glycerol and 0.5 µg/ml thiamine. Following transformation with the plasmid pMOB3, DH5 α loses the ability to grow on this media. Fragments of pMOB3 were ligated into the vector pBR322 and transformed into DH5 α. The transformants were plated on LB-Amp to select for cells that had acquired a plasmid and screened for lack of growth on LB-Tet to confirm the presence of an insert. They were then evaluated for their ability to grow on supplemented M9 minimal media. Plasmids were isolated from colonies that did not exhibit growth on either LB-Tet or supplemented M9 minimal media, and inserted fragments were excised by digestion with restriction endonucleases. Our results demonstrate that a fragment of pMOB3 is responsible for the inhibition of growth of DH5 α on supplemented M9 minimal media.