Limosilactobacillus reuteri, 2021

Li, Fuyong, Cheng, Christopher C., Zheng, Jinshui, Liu, Junhong, Quevedo, Rodrigo Margain, Li, Junjie, Roos, Stefan, Gänzle, Michael G. & Walter, Jens, 2021, Limosilactobacillus balticus sp. nov., Limosilactobacillus agrestis sp. nov., Limosilactobacillus albertensis sp. nov., Limosilactobacillus rudii sp. nov. and Limosilactobacillus fastidiosus sp. nov., five novel Limosilactobacillus species isolated from the vertebrate gastrointestinal tract, and proposal of six subspecies of Limosilactobacillus reuteri adapted to the gastrointestinal tract of specific vertebrate hosts, International Journal of Systematic and Evolutionary Microbiology (004644) 71 (2), pp. 1-21 : 18

DESCRIPTION OF LIMOSILACTOBACILLUS REUTERI SUBSP. PORCINUS SUBSP. NOV.

Limosilactobacillus reuteri subsp. porcinus (por.ci′ nus. L. masc. adj. porcinus of swine, referring to the host origin of most strains of this subspecies being swine).

L. reuteri strains clustered in lineage V ( Fig. 3 ) belong to L. reuteri subsp. porcinus and they were isolated from pigs [ 5, 7]. Strains (3c6 T and 20-2) of this subspecies have an ANI value of 99.1% with each other and ANI values of 93.8–96.6% with other L. reuteri strains belonging to different subspecies ( Fig. 4 ). Acid is produced from D-ribose, D-galactose, D-glucose, maltose, lactose, melibiose, sucrose, raffinose and potassium gluconate; acid production from methyl-α- D-glucopyranoside is strain-specific; acid is not produced from L-arabinose, D-xylose, D-fructose, D-mannose, aesculin, glycerol, erythritol, D-arabinose,L-xylose,D-adonitol, methyl β -Dxylopyranoside, L-sorbose,L-rhamnose, dulcitol, inositol, D-mannitol, D-sorbitol, methyl α- D-mannopyranoside, N -acetylglucosamine, amygdalin, arbutin, salicin, cellobiose, trehalose, inulin, melezitose, starch, glycogen, xylitol, gentiobiose, turanose, D-lyxose, D-tagatose, D-fucose, L-fucose,D-arabitol,L-arabitol, potassium 2-ketogluconate or potassium 5-ketogluconate. Phylogenetic analyses based on the core genes identified in this study ( Fig. 3 ) and previous studies [ 5, 43, 46], AFLP and MLSA (using concatenated sequences of ddl, pkt, leuS, gyrB, dltA, rpoA and recA genes) [ 7] indicate that strains clustered in this lineage are pig-specific. Both 3c6 T and 20-2 possess the pdu-cbi-cob-hem cluster (pdu cluster) [ 5, 46], which equips them with the ability to utilize 1,2-propanediol and glycerol as electron acceptors [ 16, 39, 40] and to produce the antimicrobial compound reuterin [ 8].

The type strain, 3c6 T (=DSM 110571 T =LMG 31635 T), was isolated from porcine gastrointestinal tract [ 7, 46], with a DNA G+C content of 38.6mol% .

Figures

Fig. 3. A maximum-likelihood phylogenetic tree reconstructed using core genes (n=100) identified from whole-genome sequences, showing the evolutionary relationships among six L. reuteri subspecies.The tree was reconstructed using 33 L. reuteri genomes available in public databases (n=6 for L. reuteri subsp. kinnaridis, n=2 for L. reuteri subsp. porcinus, n=5 for L. reuteri subsp. murium, n=10 for L. reuteri subsp. reuteri, n=5 for L. reuteri subsp. suis and n=5 for L. reuteri subsp. rodentium) and L. balticus BG-AF3-AT was used as an outgroup. Further information on the involved genome sequences is listed in Table S1. The tree was inferred based on the GTR+G model with 1000 bootstrap replicates and only bootstrap values above 60% are shown. The tree was drawn with iTOL [54].

Fig. 4. Pairwise average nucleotide identity values (ANI; %) of genome sequences belonging to the same or different L. reuteri subspecies. ANI values within the same subspecies and between different subspecies were calculated for 33 L. reuteri genomes available in public databases (n=6 for L. reuteri subsp. kinnaridis, n=2 for L. reuteri subsp. porcinus, n=5 for L. reuteri subsp.murium, n=10for L. reuteri subsp.reuteri, n=5 for L. reuteri subsp. suis and n=5 for L. reuteri subsp. rodentium). Further information on the involved genome sequences is listed in Table S1.