Analysis and stability of Zymomonas mobilis ATCC 10988 plasmid pZMO3

Plasmid pZMO3 of Zymomonas mobilis strain ATCC 10988 was found to be nonhomologous either to chromosomal DNA or to any other plasmids of the strains ATCC 10988, NCIB 11163, and CP4. It contained single sites for the restriction endonucleases SphI, BglI, and HindIII, as well as at least four sites for Sau3A. Its origin of replication is located within the 1.54-kb Sau3A fragment as it was found that only the recombinant plasmid pDS3154, which contained this fragment, showed vectorial incompatibility with the native pZMO3 plasmid. The stability of pZMO3 may be controlled by partitioning sequences located in the 0.64-kb Sau3A fragment. Z. mobilis isolates, which had lost plasmid pZMO3, were successfully isolated.