Engineering of Bacillus subtilis 168 for Increased Nisin Resistance

Suppressor system in Bacillus subtilis 168.

Multiple auxotrophic strains of Bacillus subtilis 168 were tested for joint one-step reversion of two or more auxotrophic markers to the wild-type phenotype. Mu8u5u5, a strain requiring leucine, methionine, and threonine, yielded revertants that grew without added methionine or threonine and proved to have a suppressor gene. When transferred by transformation with deoxyribonucleic acid, this su...

Bacillus subtilis 168 4 5 6

Introduction of host-controlled modification and restriction systems of Bacillus subtilis IAM1247 into Bacillus subtilis 168.

Bacillus subtilis IAM1247 had two modification and restriction systems (Bsu1247I and Bsu1247II), the former producing an isoschizomer of PstI endonuclease. A transformant clone was isolated which had Bsu 168, BsuR, and Bsu1247I systems coexisting within a genome.

Transformation and transfection in lysogenic strains of Bacillus subtilis 168.

Strains of Bacillus subtilis lysogenic for either temperate bacteriophage phi105 or SPO2 were reduced to less than 1.0% of the level of transformation of the nonlysogenic strains. Strains lysogenic for both phi105 and SPO2 are virtually nontransformable, indicating that the effect of lysogeny is additive. Lysogenic cultures transfected at essentially wild-type levels with deoxyribonucleic acid ...

Restriction on conjugational transfer of pLS20 in Bacillus subtilis 168.

Conjugational transfer of pLS20 in Bacillus subtilis Marburg 168 is restricted by the BsuM restriction-modification system. Restriction efficiency was measured using pLS20 derivatives possessing various numbers of XhoI sites, which are known to be recognized by BsuM. An increase in XhoI sites clearly reduced the conjugational efficiency of pLS20 as compared with that of pUB110 plasmid lacking X...