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 Author Li, Fuyong Author Cheng, Christopher C. Author Zheng, Jinshui Author Liu, Junhong Author Quevedo, Rodrigo Margain Author Li, Junjie Author Roos, Stefan Author Gänzle, Michael G. Author Walter, Jens text International Journal of Systematic and Evolutionary Microbiology 2021 004644 2021-02-01 71 2 1 21 http://dx.doi.org/10.1099/ijsem.0.004644 journal article 10.1099/ijsem.0.004644 6b321035-fd9c-4b25-a3b6-79a05a309793 1466-5034 PMC8346765 33533708 6048739 DESCRIPTION OF LIMOSILACTOBACILLUS REUTERI SUBSP. REUTERI SUBSP. NOV. Limosilactobacillus reuteri subsp. reuteri (reu′ te.ri. N.L. gen. n. reuteri , of Reuter; named for G. Reuter, a German bacteriologist after whom the species L. reuteri was named). L. reuteri strains clustered in lineage II ( Fig. 3 ) belong to L. reuteri subsp. reuteri and they were isolated from humans and herbivores [ 7 , 43 ]. Strains of this subspecies have ANI values of 98.1–100.0% with each other and ANI values of 94.0–96.5% with other L. reuteri strains belonging to different subspecies ( Fig. 4 ). Acid is produced from L-arabinose,D-ribose, D-galactose,D-glucose, maltose, lactose, melibiose, sucrose and raffinose; acid production from potassium gluconate is strain-specific; acid is not produced from D-xylose,D-fructose, D-mannose, methylα- D-glucopyranoside, 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 ], AFLP and MLSA (using concatenated sequences of ddl , pkt , leuS , gyrB , dltA , rpoA and recA genes) [ 7 ], suggest that these strains are genetically homogeneous [ 8 ]. Strains of this subspecies possess the pdu-cbi-cob-hem cluster ( pdu cluster) [ 6 , 8 ], 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 ]. They also produce histamine from histidine that has been linked to their anti-inflammatory phenotype [ 34 ]. Strains belonging to this subspecies have been considered as immunosuppressive because they could suppress the proinflammatory cytokines tumour necrosis factor (TNF), monocyte chemoattractant protein (MCP)-1, interleukin (IL)-1 β and IL-12, as well as suppress intestinal inflammation [ 34 ]. The type strain, DSM 20016 T (=ATCC 23272 T =F 275 T [original designation]), was isolated from the gastrointestinal tract of an adult human [ 6 , 44 , 45 ], with a DNA G+C content of 38.9mol%.