Lactobacillus formosensis sp. nov., a lactic acid bacterium isolated from fermented soybean meal

Lactobacillus delbrueckii subsp. bulgaricus strain TCI904 reduces body weight gain, modulates immune response, improves metabolism and anxiety in high fat diet-induced obese mice

The multiple probiotic characteristics of strain TCI904 isolated in this study from natural fermented milk were investigated using a mouse model. TCI904 was identified as Lactobacillus delbrueckii subsp. bulgaricu (LDB), a well-known lactic acid starter bacterium found in yogurt. TCI904 exhibited an outstanding pancreatic lipase inhibition activity among several strains of lactic acid bacteria in vitro. Its in vivo effects were further studied. In a comparison of mice fed a high-fat diet (HFD) and those fed a HFD combined with TCI904 for 9 weeks, differences were observed in various aspects of health, and the adverse effects of a HFD were prevented in the latter group. TCI904 effectively prevented fat and body weight accumulation without reducing food intake; it also modulated innate immunity and increased the level of IgA in feces, reversing the increased blood sugar and insulin levels and attenuated the hyperlipidemia caused by a HFD. Based on biochemical test data, compared with the HFD group, a HFD combined with TCI904 induced significant lowering of insulin resistance indicator, homeostasis model assessment-insulin resistance (HOMA-IR) and atherogenic indices of plasma (AIP), the atherogenic coefficient (AC) and cardiac risk ratio (CRR) and increased the cardioprotective index (CPI). In addition, the administration of TCI904 alleviated mood disorders caused by a HFD. Taking the recommended human dose of TCI904 did not affect the liver or kidney function, indicating that TCI904 has sufficient in vivo safety. Taken together, the results of the present study contributed towards validation of the probiotic benefits of lactic acid starter microflora. Orally taken TCI904 exhibited positive immune- and metabolic-modulating, and anxiolytic properties, especially in HFD-induced obesity.

EFSA Panel on Biological Hazards (BIOHAZ), Koutsoumanis K, Allende A, Alvarez‐Ordóñez A, Bolton D, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Cocconcelli PS, Fernández Escámez PS, Maradona MP, Querol A, Sijtsma L, Suarez JE, Sundh I, Vlak J, Barizzone F, Hempen M, Correia S, Herman L. Update of the list of QPS-recommended microbiological agents intentionally added to food or feed as notified to EFSA 16: suitability of taxonomic units notified to EFSA until March 2022

The qualified presumption of safety (QPS) approach was developed to provide a regularly updated generic pre-evaluation of the safety of microorganisms, intended for use in the food or feed chains, to support the work of EFSA's Scientific Panels. The QPS approach is based on an assessment of published data for each agent, with respect to its taxonomic identity, the body of relevant knowledge, safety concerns and occurrence of antimicrobial resistance. Safety concerns identified for a taxonomic unit (TU) are, where possible, confirmed at the species/strain or product level and reflected by 'qualifications'. In the period covered by this statement, no new information was found that would change the status of previously recommended QPS TUs. Of the 50 microorganisms notified to EFSA in October 2021 to March 2022 (inclusive), 41 were not evaluated: 10 filamentous fungi, 1 Enterococcus faecium, 1 Clostridium butyricum, 3 Escherichia coli and 1 Streptomyces spp. because are excluded from QPS evaluation, and 25 TUs that have already a QPS status. Nine notifications, corresponding to seven TUs were evaluated: four of these, Streptococcus salivarius, Companilactobacillus formosensis, Pseudonocardia autotrophica and Papiliotrema terrestris, being evaluated for the first time. The other three, Microbacterium foliorum, Pseudomonas fluorescens and Ensifer adhaerens were re-assessed. None of these TUs were recommended for QPS status: Ensifer adhaerens, Microbacterium foliorum, Companilactobacillus formosensis and Papiliotrema terrestris due to a limited body of knowledge, Streptococcus salivarius due to its ability to cause bacteraemia and systemic infection that results in a variety of morbidities, Pseudonocardia autotrophica due to lack of body of knowledge and uncertainty on the safety of biologically active compounds which can be produced, and Pseudomonas fluorescens due to possible safety concerns.

Companilactobacillus pabuli sp. nov., a lactic acid bacterium isolated from animal feed

A Gram-positive, facultative anaerobic, catalase-negative, non-motile, non-spore-forming and rod-shaped lactic acid bacterium strain, denoted as NFFJ11^T and isolated from total mixed fermentation feed in the Republic of Korea, was characterized through polyphasic approaches, including sequence analyses of the 16S rRNA gene and housekeeping genes (rpoA and pheS), determination of average nucleotide identity and in silico DNA-DNA hybridization, fatty acid methyl ester analysis, and phenotypic characterization. Phylogenetic analyses based on 16S rRNA, rpoA and pheS gene sequences revealed that strain NFFJ11^T belonged to the genus Companilactobacillus. The 16S rRNA gene sequence of strain NFFJ11^T exhibited high similarity to Companilactobacillus formosensis S215^T (99.66 %), Companilactobacillus farciminis Rv4 na^T (99.53 %), Companilactobacillus crustorum LMG 23699^T (99.19 %), Companilactobacillus futsaii YM 0097^T (99.06 %), Companilactobacillus zhachilii HBUAS52074^T (98.86 %) and Companilactobacillus heilongiiangensis S4-3^T (98.66 %). However, average nucleotide identity and in silico DNA-DNA hybridization values for these type strains were in the range of 79.90-92.93 % and 23.80-49.30 %, respectively, which offer evidence that strain NFFJ11^T belongs to a novel species of the genus Companilactobacillus. The cell-wall peptidoglycan type was A4α (l-Lys-d-Asp) and the G+C content of the genomic DNA was 35.7 mol%. The main fatty acids of strain NFFJ11^T were C_18 : 1  ω9c (43.3 %), C_16 : 0 (20.1 %) and summed feature 7 (18.3 %; comprising any combination of C_19 : 1  ω7c, C_19 : 1  ω6c and C_19 : 0 cyclo ω10c). Through polyphasic taxonomic analysis, it was observed that strain NFFJ11^T represents a novel species belonging to the genus Companilactobacillus, for which the name Companilactobacillus pabuli sp. nov. is proposed. The type strain is NFFJ11^T (= KACC 21771^T= JCM 34088^T).

Leuconostoc litchii sp. nov., a novel lactic acid bacterium isolated from lychee

A novel lactic acid bacterium, strain MB7^T, was isolated from lychee in Taiwan. MB7^T is Gram-staining-positive, catalase-negative, non-motile, non-haemolytic, facultatively anaerobic, coccoid-shaped, heterofermentative and mainly produces d-lactic acid from glucose. Comparative analysis of 16S rRNA, pheS and rpoA gene sequences has demonstrated that the novel strain represented a member of the genus Leuconostoc. 16S rRNA gene sequencing results indicated that MB7^T had the same sequence similarity of 99.25 % to four type strains of members of the genus Leuconostoc: Leuconostoc mesenteroides subsp. dextranicum DSM 20484^T, Leuconostoc mesenteroides subsp. jonggajibkimchii DRC 1506^T, Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293^T and Leuconostoc suionicum DSM 20241^T. Additionally, high 16S rRNA sequence similarities were also observed with Leuconostoc mesenteroides subsp. cremoris ATCC 19254^T (99.12 %) and Leuconostoc pseudomesenteroides NRIC 1777^T (98.69 %). When comparing the genomes of these type strains, the average nucleotide identity values and digital DNA-DNA hybridization values of MB7^T with these type strains were 76.57-80.53 and 22.0-22.6 %, respectively. MB7^T also showed different phenotypic characteristics to other most closely related species of the genus Leuconostoc, such as carbohydrate metabolizing ability, halotolerance and growth at various pHs. On the basis of phenotypic and genotypic properties, strain MB7^T represents a novel species belonging to the genus Leuconostoc, for which the name Leuconostoc litchii sp. nov. is proposed. The type strain is MB7^T (=BCRC 81077^T=NBRC 113542^T).

A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae

The genus Lactobacillus comprises 261 species (at March 2020) that are extremely diverse at phenotypic, ecological and genotypic levels. This study evaluated the taxonomy of Lactobacillaceae and Leuconostocaceae on the basis of whole genome sequences. Parameters that were evaluated included core genome phylogeny, (conserved) pairwise average amino acid identity, clade-specific signature genes, physiological criteria and the ecology of the organisms. Based on this polyphasic approach, we propose reclassification of the genus Lactobacillus into 25 genera including the emended genus Lactobacillus, which includes host-adapted organisms that have been referred to as the Lactobacillus delbrueckii group, Paralactobacillus and 23 novel genera for which the names Holzapfelia, Amylolactobacillus, Bombilactobacillus, Companilactobacillus, Lapidilactobacillus, Agrilactobacillus, Schleiferilactobacillus, Loigolactobacilus, Lacticaseibacillus, Latilactobacillus, Dellaglioa, Liquorilactobacillus, Ligilactobacillus, Lactiplantibacillus, Furfurilactobacillus, Paucilactobacillus, Limosilactobacillus, Fructilactobacillus, Acetilactobacillus, Apilactobacillus, Levilactobacillus, Secundilactobacillus and Lentilactobacillus are proposed. We also propose to emend the description of the family Lactobacillaceae to include all genera that were previously included in families Lactobacillaceae and Leuconostocaceae. The generic term 'lactobacilli' will remain useful to designate all organisms that were classified as Lactobacillaceae until 2020. This reclassification reflects the phylogenetic position of the micro-organisms, and groups lactobacilli into robust clades with shared ecological and metabolic properties, as exemplified for the emended genus Lactobacillus encompassing species adapted to vertebrates (such as Lactobacillus delbrueckii, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus jensensii, Lactobacillus johnsonii and Lactobacillus acidophilus) or invertebrates (such as Lactobacillus apis and Lactobacillus bombicola).

Lactobacillus xujianguonis sp. nov., isolated from faeces of Marmota himalayana

Two novel strains (HT111-2^T and HT170-2) of the genus Lactobacillus were isolated from Marmota himalayana faecal samples collected on the Qinghai-Tibet Plateau, PR China. The isolates were Gram-stain-positive, rod-shaped, non-spore-forming bacteria with irregular circular colonies. Phylogenetic analysis and comparison of the 16S rRNA gene sequences demonstrated that the two strains form a subcluster and are closest to Lactobacillus hamsteri JCM 6256^T (97.3 %) and Lactobacillus amylolyticus DSM 11664^T (97.2 %). Phylogenetic analysis of two housekeeping genes (rpoA and pheS) found that strains HT111-2^T and HT170-2 had the same closest relatives as the 16S rRNA gene sequence analysis did. The G+C content of strains HT111-2^T and HT170-2 were 38.8 mol%. The values of in silico DNA-DNA hybridization with known Lactobacillus species were lower than the threshold (70%). Average nucleotide identity values of strain HT111-2^T with L. hamsteri JCM 6256^T and L. amylolyticus DSM 11664^T were 77.84 % and 76.85 %, respectively. The major fatty acids of strains HT111-2^T and HT170-2 were C_16 : 0, C_18 : 1ω9c and C_18 : 0. Results of phenotypic, chemotaxonomic and phylogenetic analyses suggest strains HT111-2^T and HT170-2 represent a novel species of the genus Lactobacillus, for which the name Lactobacillus xujianguonis sp. nov. is proposed with HT111-2^T (=CGMCC 1.13855^T=KCTC 15803^T) as the type strain.