Determination of plasmid transfer frequency in soil: Consequences of bacterial mating on selective agar media

摘要: The possible occurrence of bacterial matings on transconjugant-selective plates used in experiments aimed at assessing conjugal transfer soil was investigated. Matings (with rifampicin, streptomycin, tetracycline, and kanamycin) between donor recipient cells were shown to occur depending the number parent cells. Temperature also influenced conjugation frequencies agar plates, since a lower temperature resulted decreased transconjugants. use nalidixic acid instead streptomycin conjunction with rifampicin for counter selection inhibited selective plates. Conjugation analyzed by plating media or streptomycin. results indicated that bentonite- nutrient-amended readily detected; however, part transconjugants could be assigned result stimulated presence plant roots. Colony hybridization confirmed plasmid RP4