Plasmid-determined 2-hydroxypyridine utilization by Arthrobacter crystallopoietes.

Arthrobacter crystallopoietes has the ability to utilize 2-hydroxypyridine (2-HP) as a source of carbon and nitrogen and forms a blue extracellular pigment when grown in the presence of 2-HP. Ultracentrifugal analyses of pigment producing (Pig+) and pigment nonproducing (Pig-) strains of A. crystallopoietes revealed the presence of plasmid material in both strains. Recovery of plasmid DNA from Pig+ strains is two or three times greater than from Pig- strains. The molecular weight of plasmid DNA recovered from Pig+ strains (62 Mdaltons) is slightly higher than the molecular weight of plasmid DNA from Pig- strains. Consistent with the characterization of plasmid DNA from the two strains is that Pig+ strains contain a 63-Mdalton plasmid encoding 2-HP utilization as well as a cryptic plasmid of very nearly equal molecular weight. Pig- strains contain only the cryptic plasmid.