Novel plasmids from alkaliphilic halomonads

Seventeen alkaliphilic halomonads were examined for the presence of plasmid s. Of these, eight strains harbored one or more from 5.3 to 33 kb in size, the first plasmids to be identified from an alkaliphilic halomonad source. Restriction and hybridization analysis revealed three strains that maintain ed an identical 5.9-kb plasmid which we named pAH1, two that had an identic al 33-kb plasmid, and three others, of which one carried two plasmids of 5. 3 and 15 kb, the former being designated pAH2. The two final strains mainta ined plasmids of 15 and 20.5 kb. Restriction mapping of both pAH1 and pAH2 indicated that they have a number of unique restriction sites and are of a small enough size to make them suitable for vector construction. (C) 1999 A cademic Press.