[Genetic transfer of pAP38, pAP39, and pAP41 plasmids into E. coli, Erwinia, and Hafnia strains]. / Geneticheskii perenos plazmid pAP38, pAP39 i pAP41 v shtammy E. coli, Erwinia i Hafnia.

Genetic transfer factors pAP38, pAP39 and pAP41 can be transferred to E. coli, both typed and untypecd, as well as to Erwinia and Hafnia strains, with different frequency (10(-2) to 10(-8)). The transconjugates thus obtained possess donor activity and can transfer the factors they have received to recipient E. coli strains. After transfer these factors are stably maintained in a new host for at least 10 days. Under the action of ethidium bromide or elevated temperature the elimination of the transfer factors from host bacteria is observed. The studied transfer factors pAP38, pAP39 and pAP41 (F-like factors) are plasmids fi+.

[Morphological characteristics and biological properties of morphological mutants of Escherichia coli K12]. / Morfologicheskaia kharakteristika i nekotorye biologicheskie svoistva morfologicheskikh mutantov Escherichia coli K12.

E. coli mutants K12, PA6021, and AB312 characterised by changed morphology were obtained. Various morphological elements encountered in the mutant populations, and the capacity to phenotypical reversion are described. Some other properties (cultural, tinctorial, mobility, osmotic stability) changed in the mutants under study in addition to morphology.