Transfer of broad host range plasmids to the type I obligate methanotroph Methylomonas albus

Abstract

SUMMARYPlasmids RP4 (IncP) and R300B (IncQ) (mobilized by RP4) were transferred to Methylomonas albus from Escherichia coli donors at frequencies of 2 × 10 3 and 1-10 3 per donor. BY contrast, plasmids pS-a (IncW) and the IncP plasmids R68.45, R751 and derivatives carrying bacteriophage Mu and/or transposons were transferred to M. albus from E. coli at frequencies of 10 7-10-8 per donor. M. albus transconjugants carrying R68.45, R751 and their derivatives were isolated and used as donors in matings with either other strains of M. albus or E. coli. Plasmids carrying bacteriophage Mu were transferred to E. coli at a frequency of 10 5-10-6 per donor and 10 2-10 3 per donor for those not carrying Mu. Transfer to M. albus recipients was at a frequency of 10 3-10 -4 per donor regardless of the presence or absence of Mu, indicating the absence of a suicide effect. Plasmids carrying Tn5 were found in M. albus to determine simultaneous kanamycin (Km) and streptomycin (Sm) resistance.

Genetics and molecular biology of methanotrophs

“…Using filter matings, the Inc. P plasmids R68.45, R751, and derivatives carrying bacteriophage Mu and/or transposons and pS-a (Inc W plasmids) were transferred to M. albus from E. Table 1 Plasmids transferred to methanotrophs by conjugation 237 coli at frequencies of 10 -7 to 10 -s. Higher frequencies were noted for RP4 and R300B (10-3). Transfer frequencies for Mu-containing plasmids indicated that the Mu-associated suicide phenomenon did not occur in M. a/bus [53]. In a similar study, AI-Taho and Warner successfully transferred pULBll3, a derivative of RP4 into which a deleted fragment of bacteriophage Mu has been inserted, from E. coli to M. trichosporium OB3b again using filter matings [54].…”

Physiology and genetics of methylotrophic bacteria

“…These differences in transfer frequencies could reflect the actual physical efficiencies of the conjugation systems under study. For instance, RP4 is transferred at a frequency of 10-"~/donor from Escherichia colt into Methylomonas albus, but lhe IncW plasmic pSa at a frequency of 10+7/donor [259]. Efficiencies of transfer may a!so be influenced by differential susceptibility of plasmids to the various host-dependent restriction systems since, using the s~me conjugation system, transfer efficieneies of different plasmids into a particular host may vary considerably (1207], see Table 3).…”

Conjugation and heterologous gene expression in Gluconobacter oxydans ssp. suboxydans

“…suboxydans which could account for the differential transfer frequencies was also considered. McPheat et al [14] have shown a 5-6-fold increase in conjugation frequencies in Methylomonas aibus by subjecting this strain to heat shock (1 min at 50 ° C) before conjugation. However, we were not able to observe a significant increase in conjugation frequencies as a result of heat shock and conclude that a host restriction system does not appear to limit conjugal establishment of broad host range plasmids in G. oxydans ssp.…”