Lentilactobacillus kosonis sp. nov., isolated from kôso, a Japanese sugar-vegetable fermented beverage

Lactic Acid Bacteria Strains Isolated from Jerusalem Artichoke (Helianthus tuberosus L.) Tubers as Potential Probiotic Candidates

The search for probiotic candidates is an area that accompanies the world trend of development of novel probiotic strains and new products. In recent years, unconventional sources of potential probiotic bacteria have been studied. Furthermore, there has been an increasing interest in non-dairy and plant-based probiotic foods, currently being considered as a priority for the food industry. The aim of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from Jerusalem artichoke tubers. These strains were characterized by in vitro tests for their biochemical and probiotic properties and safety aspects. The results demonstrated that the LAB strains isolated exhibited a survival rate after acid exposure exceeding 90%, maintained viability above 88% under simulated gastrointestinal conditions, and the autoaggregation capacity ranged from 61 to 81%. Additionally, the strains showed no hemolytic activity and were sensitive to antibiotics. The isolates also downregulated the proinflammatory responses and showed antimicrobial activity against E. coli and B. cereus. The bacilli strains showed a high similarity with Lentilactobacillus kosonis and Lentilactobacillus curieae. Hence, these strains revealed potential probiotic in vitro characteristics that position them to be used in plant-based functional food. This strategic exploration of probiotic bacteria sourced from vegetables not only enhances the diversity of available strains-both taxonomically and functionally-but also fosters the development of sustainable, plant-based probiotic applications.

Lentilactobacillus terminaliae sp. nov., isolated from tree bark (Terminalia ivorensis Chev.) and its antioxidant activity

A Gram-stain-positive, facultatively anaerobic, rod-shaped strain, designated SPB1-3T, was isolated from tree bark. This strain exhibited heterofermentative production of dl-lactic acid from glucose. Optimal growth was observed at 25-40 °C, pH 4.0-7.0, and in the presence of 3% (w/v) NaCl. The cell wall peptidoglycan contained lysine and aspartic acid. The predominant fatty acids identified were C16:0 and the Summed feature 7 (C19 :1  ω7c/C19:1  ω6c and/or C19:1  ω6c/ω7c/19cy). The polar lipid profile included phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol, along with two unidentified phospholipids, two unidentified amino lipids and two unidentified lipids. Phylogenetic analysis based on 16S rRNA gene sequences positioned strain SPB1-3T within the genus Lentilactobacillus, showing a close relation to Lentilactobacillus kosonis NBRC 111893T (99.86%) and Lentilactobacillus curieae CCTCC M 2011381T (98.65%). The whole genome of strain SPB1-3T comprised 1 932 998 base pairs with 1955 coding genes and a DNA G+C content of 37.8%. Digital DNA-DNA hybridization between strain SPB1-3T and closely related type strains ranged from 19.50 to 27.20%. The average nucleotide identity ranged from 84.21 to 85.56%, and the average amino acid identity ranged from 57.25 to 85.99%, both falling below the established thresholds for species delineation. Strain SPB1-3T was clearly distinguishable from related Lentilactobacillus species based on its phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence similarity and whole genome analysis. Additionally, the strain exhibited radical scavenging activity at 66.92% and demonstrated 82.32% inhibition in the tyrosinase inhibitory assay. These findings support the classification of strain SPB1-3T as a novel species within the genus Lentilactobacillus, for which the name Lentilactobacillus terminaliae sp. nov. is proposed. The type strain is SPB1-3T (=JCM 35081T=TISTR 10005T).

Elevation of Lentilactobacillus rapi subsp. dabitei Li et al. 2022 to the species level as Lentilactobacillus dabitei sp. nov

Lentilactobacillus rapi subsp. dabitei was proposed by Li et al. in 2022. The type strains of L. rapi subsp. dabitei and L. rapi subsp. rapi shared 93.1 % average nucleotide identity and 52.8 % digital DNA-DNA hybridization values. Strain IMAU80584T was proposed as a novel subspecies of L. rapi rather than a novel species of the genus Lentilactobacillus on the basis of similar phenotypic characteristics (including growth temperature and pH, tolerance to NaCl and features based on API 50CH and API ZYM). However, the phenotypic investigation performed by Li et al. was insufficient because some physiological and biochemical characteristics recommended by Mattarelli et al. were not included. In the present study, the taxonomic relationship between L. rapi subsp. dabitei and L. rapi subsp. rapi was re-evaluated. Based upon the data obtained in the present study, we propose to elevate L. rapi subsp. dabitei to the species level as Lentilactobacillus dabitei sp. nov. The type strain is IMAU80584T (=GDMCC 1.2566T=JCM 34647T).

Draft Genome Sequence of Lentilactobacillus kosonis NBRC 111893, Isolated from a Japanese Sugar-Vegetable Fermented Beverage called Kôso

Lentilactobacillus kosonis NBRC 111893 is a species of heterolactic acid bacteria isolated from kôso, a Japanese sugar-vegetable fermented beverage. The draft genome sequence of L. kosonis NBRC 111893 is useful for understanding the features of the genus Lentilactobacillus and its possible uses in fermented foods.