Identification of restriction-modification systems of Bifidobacterium animalis subsp. lactis CNCM I-2494 by SMRT sequencing and associated methylome analysis

PLoS One. 2014 Apr 17;9(4):e94875. doi: 10.1371/journal.pone.0094875. eCollection 2014.

Abstract

Bifidobacterium animalis subsp. lactis CNCM I-2494 is a component of a commercialized fermented dairy product for which beneficial effects on health has been studied by clinical and preclinical trials. To date little is known about the molecular mechanisms that could explain the beneficial effects that bifidobacteria impart to the host. Restriction-modification (R-M) systems have been identified as key obstacles in the genetic accessibility of bifidobacteria, and circumventing these is a prerequisite to attaining a fundamental understanding of bifidobacterial attributes, including the genes that are responsible for health-promoting properties of this clinically and industrially important group of bacteria. The complete genome sequence of B. animalis subsp. lactis CNCM I-2494 is predicted to harbour the genetic determinants for two type II R-M systems, designated BanLI and BanLII. In order to investigate the functionality and specificity of these two putative R-M systems in B. animalis subsp. lactis CNCM I-2494, we employed PacBio SMRT sequencing with associated methylome analysis. In addition, the contribution of the identified R-M systems to the genetic accessibility of this strain was assessed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Bifidobacterium / genetics*
  • DNA Methylation*
  • Escherichia coli / genetics
  • Genome, Bacterial / genetics
  • Genomics / methods*
  • Plasmids / genetics
  • Restriction Mapping / methods*
  • Sequence Analysis / methods*

Grants and funding

This work was financially supported by Danone, a HRB postdoctoral fellow–Grant no. PDTM/20011/9 and by Science Foundation Ireland (SFI), through the Irish Government's National Development Plan (grant nos. 07/CE/B1368 and SFI/12/RC/2273). The funder, Danone, funded the research and provided support in the form of salaries for authors PG, CC, JvHV and TS. The specific roles of these authors are articulated in the ‘author contributions’ section.