Introduction of Tn916 and pAM beta 1 into Streptococcus bovis JB1 by conjugation.

The transposon Tn916 and self-mobilizing plasmid pAM beta 1 were conjugated from Enterococcus faecalis to the ruminal bacterium Streptococcus bovis JB1. Transconjugants were identified by resistance to tetracycline (Tn916) or erythromycin (pAM beta 1) and by Southern hybridization analyses. Transfer frequencies were 7.0 x 10(-6) and 1.0 x 10(-6) per recipient cell for Tn916 and pAM beta 1, respectively. The transconjugants JB1/Tn916 and JB1/pAM beta 1 were used as donors for matings with E. faecalis, Bacillus subtilis, and the ruminal bacterium Butyrivibrio fibrisolvens. While pAM beta 1 was successfully transferred to all three organisms, Tn916 was transferred only into B. subtilis and B. fibrisolvens at very low frequencies. This is the first report of conjugal DNA transfers between two ruminal organisms.