Properties of the Cell Walls of Lactococcus lactis subsp. cremoris SK110 and SK112 and Their Relation to Bacteriophage Resistance

Abstract

Resistance of Lactococcus lactis subsp. cremoris SK110 to bacteriophage skllG, encoded on the plasmid pSK112, is due to poor phage adsorption. Its phage-sensitive variant SK112, cured of pSK112, adsorbs phages effectively. Incubation of SK112 with concanavalin A remarkably reduced phage adsorption to this strain. This treatment also caused agglutination of SK112 that was not found with SK110, indicating different concanavalin A adsorption characteristics of cell walls of both strains. The differences between the two strains were reduced by a mild alkali treatment of cells. This resulted in a positive agglutination with concanavalin A for both strains and in parallel adsorption of phage skllG to both. Moreover, isolated cell walls of the two strains were investigated, and both bound phage skllG. These observations suggest the presence of phage receptor material in SK112 as well as in SK110. SK110 contained a relatively high level of bound galactose when compared with the phage-sensitive SK112. After the mild alkali treatment, however, the galactose content of SK110 was diminished such that it became comparable with that of SK112. It is hypothesized that the alkali treatment liberates a galactose-containing component from the cell wall and causes phage sensitivity in L. lactis subsp. cremoris SK110.

Phages of Lactobacillus casei/paracasei: response to environmental factors and interaction with collection and commercial strains

“…The vegetative cycle of viral multiplication is initiated by phage specific adsorption to the cell wall of a susceptible bacterial host (Neve 1996). Although the adsorption process was studied for other acid lactic bacteria (Budde-Niekiel and Teuber 1987;Sijtsma et al 1988;Valyasevi et al 1990;Monteville et al 1994;Foschino et al 1995;Quiberoni and Reinheimer 1998;Binetti et al 2002;Lu et al 2003;Quiberoni et al 2004) the information available on Lact. casei/paracasei is still scarce since it was only reported for system /PL-1/Lact.…”

Adsorption of temperate phages ofLactobacillus delbrueckiistrains and phage resistance linked to their cell diversity

“…The first step in the phage biology is the adsorption on the host cell surface. Phage adsorption process was studied for several species of LAB (Sijtsma et al 1988;Valsayevi et al 1990;Monteville et al 1994;Caso et al 1995;Foschino et al 1995;Quiberoni and Reinheimer 1998;Binetti et al 2002;Quiberoni et al 2004;Capra et al 2006;Müller-Merbach et al 2007;Suárez et al 2008b;Briggiler Marcó et al 2010). All these studies have been performed for lytic phages, the temperate ones being the least studied.…”

The conjugative plasmid pTR2030 encodes two bacteriophage defense mechanisms in lactococci, restriction modification (R+/M+) and abortive infection (Hsp+)

“…The presence of (at least) two independent phage resistance mechanisms on a single conjugative plasmid could be expected to confer a distinct advantage upon a population which is subject to phage attack. This appears to be true for pTR2030 transconjugants, which exhibit prolonged resistance under industrial conditions in which parental strains have failed because of phage attack (13,17,22).…”