[Coexistent effect of clay minerals on transfer frequency of plasmid DNA to fecal coliforms isolated from ground water].
The influence of coexisting clay minerals on transfer frequencies of the self-transmissible wide-host-range plasmid R68 and the wide-host-range cloning vector R1162 mobilizing by the plasmid R68 were examined for 42 strains of fecal coliforms which were screened from ground water for their ability to express rifampicin-resistant characteristics. Broth-mating procedures revealed that 14 isolates possessed an ability to receive the plasmid R68 and 8 of them possessed an ability to mobilize the vector R1162 by the plasmid R68. Transfer frequencies of the plasmid R68 and the vector R1162 by R68 mobilization were accelerated significantly with increase in the coexisting of kaoline, montmorillonite-Na, bentonite I-Na and bentonite II-Ca in the broth-mating condition. However, mobilization of the vector R1162 reached steady state by the addition of more than 1.0 mg/ml of the reagents. In the 8 isolates identified as recipient active for the vector R1162 by R68 mobilization, bentonite II-Ca, montmorillonite-Na, bentonite I-Na and kaoline had mobilization effects in that order under similar 1.0 mg/ml broth-mating conditions. It became clear that the highly effective transfer frequency of vector R1162 by R68 mobilization using bentonite II-Ca in an aqueous condition was superior to that using a solid surface plate-mating procedure.
Nakamura
S
S
Department of Food and Nutrition, Ube College.
D004269:DNA, Bacterial / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005822:Genetic Vectors; D008903:Minerals; D011815:R Factors / Q000235:genetics*; D012293:Rifampin; D014162:Transfection; D014871:Water Microbiology
D004269:DNA, Bacterial; D008903:Minerals; D012293:Rifampin