Bacillus subtilis generates a major specific deletion in pAM beta 1

Abstract

pAMj1, a 26.5-kilobase plasmid originally isolated from Streptococcus faecalis, was conjugally transferred from Streptococcus lactis to Bacillus subtilis. No conjugal transfer of pAM01 from B. subtilis to S. lactis was observed. In addition, pAM,I1 which had been reintroduced in S. lactis after cycling through B. subtilis had lost its conjugal transferability to Streptococcus cremoris, although under the same conditions noncycled pAMI1 was transferred at high efficiency. Restriction and Southern blot analyses showed that pAM01 had suffered one major, specific 10.6-kilobase deletion and several minor but also specific deletions in B. subtilis. Comparing the major deletion derivative, ApAMjI1, with B. subtilis strains which have been reported to contain pAMII1 showed that these strains also contained ApAM,1. Hybridization experiments showed that the deleted fragment was not transposed to the B. subtilis chromosome. Based on the size of the minor deletion derivatives from pAMII1, it is suggested that these use a different origin of replication in B. subtilis. Plasmid pAMP1 is a 26.5-kilobase (kb) plasmid expressing resistance to the MLS (macrolide-lincosamide-streptogramin B) group of antibiotics (40). The plasmid, originally isolated from Streptococcus faecalis DS5 (6), is conjugally transferable to and between a number of other Streptococcus species (11, 17), including Streptococcus lactis (10), various Lactobacillus species (11, 33, 38), Staphylococcus aureus (8, 32), Clostridium acetobutylicum (27, 41), and various species of Bacillus (19, 25), including Bacillus subtilis (15, 27). Although conjugal transfer of pAMP1 from S. lactis to B. subtilis has been reported (27), no data are available on conjugal transfer of pAMP1 from B. subtilis to S. lactis. This

Effect of Plasmid Incompatibility on DNA Transfer to Streptococcus cremoris

“…Isolation of plasmid DNA. Plasmid DNA was isolated from S. cremoris by the method of Ish-Horowicz and Burke (11) with some modifications (26). The cells were lysed at 0°C in TES buffer (50 mM Tris hydrochloride, 5 mM EDTA, 50 mM NaCl, pH 8.0) containing 20% sucrose, 5 mg of lysozyme, and 100 ,ug of mutanolysin per ml, followed by 15 min at 370C.…”

In vivo genetic systems in lactic acid bacteria

“…There are many reports of the conjugal transfer of the enterocoocal plasmid pAM/H into different strains, species and genera [64][65][66][67][68][69][70] although in some cases better results were obtained when alternative plasmids were used as in the transfer of piP501 in Pediococcus [71]. In matings between L, iactis and Bacillus subtilis a specific 10.5-kb deletion of pAMOl was observed and this prevented subsequent conjugal transfer [72]. As well as such specific reasons for poor conjugal transfer most species used with pAM#I and its related plasmids exhibit strain specificity with respect to conjugation efficiency.…”

pAMβ1-Associated Mobilization of Proteinase Plasmids from Lactococcus lactis subsp. lactis UC317 and L. lactis subsp. cremoris UC205

“…lactis and Lactobacillus casei (15). It differs, however, from regions of pAM31 implicated in the formation of other pAM,1 deletion derivatives (20,23,40). Characterization of a greater number of pCI210-like plasmids will provide further information on the nature of the pCI203: :pAMP1 recombination event.…”