Plasmid pGBG1 was constructed to isolate mobile genetic elements in a wide
variety of gram-negative bacteria. The mutation target, carried on a broad-
host-range vector, allows positive selection for tetracycline resistance. I
n tests using several gram-negative bacteria we could detect transposition
events of either insertion sequences or transposons. A new insertion sequen
ce (IS) element was identified in Ralstonia eutropha. (C) 2000 Academic Pre
ss.