2009 Volume 45 Issue 4 Pages 185-191
Conjugation of a self-transmissible, broad-host-range, mercury resistant plasmid pJP4 harbored in Escherichia coli HB101 into activated sludge bacteria was investigated. Filter mating experiments were performed on the nutrient agar plate with E. coli HB101 (pJP4) and the activated sludge bacteria as the donor and the recipients for conjugation, respectively. Transfer frequencies were 2.0×10–1 – 5.8×10–1 per donor and 2.2×10–1 per potential recipient. Most of the transconjugants were inferentially identified as Burkholderia cepacia and Sphingomonas paucimobilis, which are common bacteria in the activated sludge process. Some transconjugants showed higher resistance to HgCl2 (up to 100 mg/l) than the original host of pJP4, Cupriavidus necator JMP134 (50 mg/l).
