Open AccessComparative genome analysis of L actobacillus casei strains isolated from A ctimel and Y akult products reveals marked similarities and points to a common origin
Author(s) -
Douillard François P.,
Kant Ravi,
Ritari Jarmo,
Paulin Lars,
Palva Airi,
Vos Willem M.
Publication year - 2013
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12062
Subject(s) - plasmid , genome , biology , lactobacillus casei , genetics , whole genome sequencing , gene , computational biology , bacteria
Summary The members of the L actobacillus genus are widely used in the food and feed industry and show a remarkable ecological adaptability. Several L actobacillus strains have been marketed as probiotics as they possess health‐promoting properties for the host. In the present study, we used two complementary next‐generation sequencing technologies to deduce the genome sequences of two L actobacillus casei strains LcA and LcY , which were isolated from the products A ctimel and Y akult, commercialized as probiotics. The LcA and LcY draft genomes have, respectively, an estimated size of 3067 and 3082 Mb and a G + C content of 46.3%. Both strains are close to identical to each other and differ by no more than minor chromosomal re‐arrangements, substitutions, insertions and deletions, as evident from the verified presence of one insertion‐deletion ( InDel ) and only 29 single‐nucleotide polymorphisms ( SNPs ). In terms of coding capacity, LcA and LcY are predicted to encode a comparable exoproteome, indicating that LcA and LcY are likely to establish similar interactions with human intestinal cells. Moreover, both L . casei LcA and LcY harboured a 59.6 kb plasmid that shared high similarities with plasmids found in other L . casei strains, such as W56 and BD‐II . Further analysis revealed that the L . casei plasmids constitute a good evolution marker within the L . casei species. The plasmids of the LcA and LcY strains are almost identical, as testified by the presence of only three verified SNPs , and share a 3.5 kb region encoding a remnant of a lactose PTS system that is absent from the plasmids of W56 and BD‐II but conserved in another smaller L . casei plasmid ( pLC2W ). Our observations imply that the results obtained in animal and human experiments performed with the A ctimel and Y akult strains can be compared with each other as these strains share a very recent common ancestor.