It soon became apparent that certain classes of bacteria (e.g. Rhizobiaceae) contained large plasmids called megaplasmids.    From Wordnik.com.  [Planet Atheism] Reference

Agrobacteria are members of the Rhizobiaceae family, which also includes the benign, nitrogen-fixing organisms Rhizobium and Sinorhizobium.    From Wordnik.com.  [Health News from Medical News Today] Reference

The idea that large megaplasmids in Rhizobiaceae could become plasmids by acquiring essential genes has been around for three decades, at least.    From Wordnik.com.  [Planet Atheism] Reference

The Rhizobiaceae is an unusual bacterial family in that all of its members have either two chromosomes or one chromosome and very large plasmids.    From Wordnik.com.  [Planet Atheism] Reference

Members of the Rhizobiaceae have genetic architectures that span single chromosomes, multiple chromosomes and circular DNA molecules (plasmids) of various sizes.    From Wordnik.com.  [Health News from Medical News Today] Reference