Vpliv prisotnosti zunajceličnih polisaharidov na občutljivost celic Lactococcus lactis za bakteriofagno okužbo

Andreja MIKLIČ; Irena ROGELJ

doi:10.14720/aas.2003.82.1.15309

Authors

Andreja MIKLIČ Univ. of Ljubljana, Biotechnical Fac., Zootechnical Dept., Groblje 3, SI-1230 Domžale, Slovenia
Irena ROGELJ Univ. of Ljubljana, Biotechnical Fac., Zootechnical Dept., Groblje 3, SI-1230 Domžale, Slovenia

DOI:

https://doi.org/10.14720/aas.2003.82.1.15309

Keywords:

microbiology, lactic acid bacteria, starters, Lactococcus lactis, bacteriophages, exopolysaccharides, adsorption inhibition

Abstract

Several lactic acid bacteria produce exopolysacharides (EPS) with different composition and structure. EPS are believed to play a role in the protection of the microbial cell against desiccation, phagocytosis, antibiotics or toxic compounds and phage attack. The effect of EPS of seventeen strains of Lactococcus lactis, isolated from starter cultures in three Slovenian dairy plants, on bacteriophage adsorption was studied. In order to determine the possible influence of EPS presence on bacteriophage adsorption, we treated cells with different chemical agents. After washing the cells with 25 mM NaOH, most of isolates were susceptible for more bacteriophages as before. EPS of studied isolates consisted mainly from galactose, glucose and xylose. The highest concentration of polysaccharides was detected in PT19 isolate (galactose 130.6 μM and xylose 146.9 μM), which was susceptible only to FPT19 phage. In the future we will try to confirm the presumption that isolates MB18, KR7, PT4, PT13 and PT19 produce EPS which mask receptors for phage adsorption.