Effect of solid particles on conjugal transfer of plasmid R100-1 in Escherichia coli.

Abstract

Effect of solid particles on transfer of plasmid R100-1 from Escherichia coli LC102 to a rifampicin-resistant mutant of E. coli DHl was investigated using nutritionally-rich (L medium) and-poor medium (supernatant of a mixed liquor). Plasmid transfer was most significantly inhibited in the presence of bentonite. The addition of 2g.1-1 bentonite decreased the specific rate of transconjugant increase in mating to one ninetieth in the former medium, and one twenty-third in the latter. Activated sludge decreased the rates to one third and one fifth, respectively, whereas sterilized activated sludge did not affect the rates.