Fructilactobacillus cliffordii sp. nov., Fructilactobacillus hinvesii sp. nov., Fructilactobacillus myrtifloralis sp. nov., Fructilactobacillus carniphilus sp. nov. and Fructobacillus americanaquae sp. nov., five novel lactic acid bacteria isolated from insects or flowers of Kangaroo Island, South Australia

Six strains, KI11_D11^T, KI4_B1, KI11_C11^T, KI16_H9^T, KI4_A6^T and KI3_B9^T, were isolated from insects and flowers on Kangaroo Island, South Australia. On the basis of 16S rRNA gene phylogeny, strains KI11_D11^T, KI4_B1, KI11_C11^T, KI16_H9^T, KI4_A6^T were found to be closely related to Fructilactobacillus ixorae Ru20-1^T. Due to the lack of a whole genome sequence for this species, whole genome sequencing of Fructilactobacillus ixorae Ru20-1^T was undertaken. KI3_B9^T was found to be closely related to Fructobacillus tropaeoli F214-1^T. Utilizing core gene phylogenetics and whole genome analyses, such as determination of AAI, ANI and dDDH, we propose that these six isolates represent five novel species with the names Fructilactobacillus cliffordii (KI11_D11^T= LMG 32130^T = NBRC 114988^T), Fructilactobacillus hinvesii (KI11_C11^T = LMG 32129^T = NBRC 114987^T), Fructilactobacillus myrtifloralis (KI16_H9^T= LMG 32131^T = NBRC 114989^T) Fructilactobacillus carniphilus (KI4_A6^T = LMG 32127^T = NBRC 114985^T) and Fructobacillus americanaquae (KI3_B9^T = LMG 32124^T = NBRC 114983^T). Chemotaxonomic analyses detected no fructophilic characters for these strains of member of the genus Fructilactobacillus. KI3_B9^T was found to be obligately fructophilic, similarly to its phylogenetic neighbours in the genus Fructobacillus. This study represents the first isolation, to our knowledge, of novel species in the family Lactobacillaceae from the Australian wild.

Pomegranate juice fermented by tannin acyl hydrolase and Lactobacillus vespulae DCY75 enhance estrogen receptor expression and anti-inflammatory effect

Phenolics are phytochemicals in plants, fruits, and vegetables have potential health-promoting efficacies. However, mostly available as a complex form. So, to increase the contents and nutritional value of the phenolic compounds, fermentation is most readily used in the food industry. Especially, the hydrolyzable tannins present in the pomegranate that can be liberated into monomolecular substances, which enhances biological activity. Thus, this study aims to convert hydrolyzable tannins to ellagic acid by fermentation using Tannin acyl hydrolase (TAH) and a novel bacteria strain Lactobacillus vespulae DCY75, respectively to investigate its effect on Estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) mRNA expression along with inflammation inhibition. As a result, the fermentation enhanced the ellagic acid content up to 70% by the synergetic effect of TAH and DCY75. Furthermore, fermented pomegranate (PG-F) increased cellular proliferation as well as upregulated the gene expression of estrogen regulators such as ERα, ERβ, and pS2 in breast cancer cell line (MCF-7), which commonly used to evaluate estrogenic activity. Moreover, to study the inflammation associated with low estrogen in menopause, we have analyzed the inhibition of nitric oxide (NO)/inducible nitric oxide synthase (iNOS) in RAW 264.7 cells. The PG-F juice did not exert any cytotoxicity in RAW 264.7 cells and inhibited NO production along with the downregulation of a major pro-inflammatory cytokine iNOS which indicates the anti-inflammatory potential of it. To sum it up, the fermented commercial pomegranate juice using a novel bacteria strain increased the amount of ellagic acid that the value added bioactive of pomegranate and it has significantly increased the estrogenic activity via upregulating estrogen related biomarkers expression and reduced the risk of related inflammation via NO/iNOS inhibition. This study could be a preliminary study to use fermented pomegranate as a potential health functional food after further evaluation.

Lactobacillus huangpiensis sp. nov. and Lactobacillus laiwuensis sp. nov., isolated from the gut of honeybee (Apis mellifera)

Four Gram-stain-positive bacterial strains were isolated from the gut of honeybee (Apis mellifera) in China. These strains were characterized using a polyphasic taxonomic approach. The data demonstrated that three of the four strains represented two novel species of the genus Lactobacillus , strains F306-1T and F551-2T were designated as the type strains. Results of 16S rRNA gene sequence analysis indicated that strains F306-1T, F447 and F551-2T were phylogenetically related to the type strains of Lactobacillus kimbladii and Lactobacillus kullabergensis , having 99.1–99.7 % 16S rRNA gene sequence (about 1400 bp) similarities. The phylogenetic tree based on concatenated pheS, rpoA, gyrB, hsp60, recA, rpoB and tuf sequences (4114 bp) and the phylogenomic tree based on whole genome sequences indicated that strains F306-1T and F447 were most closely related to L. kullabergensis Biut2NT, and strain F551-2T was most closely related to L. kimbladii Hma2NT. Strains F306-1T and F447 shared 99.9 % average nucleotide identity (ANI), 99.7 % digital DNA–DNA hybridization (dDDH) and 99.9 % average amino acid identity (AAI) values, indicating that they belong to the same species. Strain F306-1T exhibited the highest ANI (94.4 %), dDDH (56.7 %) and AAI (94.7 %) values to L. kullabergensis Biut2NT. Strain F551-2T had the highest ANI (94.0 %), dDDH (54.3 %) and AAI (95.8 %) values with L. kimbladii Hma2NT. Acid production from amygdalin, maltose, starch, gentiobiose and turanose, activity of esterase (C4) and α-glucosidase, growth with 3 % NaCl at 37 °C under strict anaerobic condition (on mMRS agar plates), and growth with 1–6% NaCl at 37 °C under aerobic condition (on mMRS agar plates supplemented with 0.05 % cysteine or with 1 % cysteine and 2 % fructose) could differentiate strains F306-1T and F447 from L. kullabergensis DSM 26262T. Acid production from d-glucose, arbutin and gentiobiose, growth with 3 % NaCl at 37 °C under strict anaerobic condition (on mMRS agar plates), and growth at 45 °C under strict anaerobic condition (on mMRS agar plates) could differentiate strain F551-2T from L. kimbladii DSM 26263T. Based upon the data obtained in the present study, two novel species, Lactobacillus huangpiensis sp. nov. and Lactobacillus laiwuensis sp. nov., are proposed and the type strains are F306-1T (=LMG 32144T=JCM 34361T=CCTCC AB 2020300T) and F551-2T (=JCM 34502T=CCTCC AB 2021027T), respectively.

Optimization of a cultivation procedure to selectively isolate lactic acid bacteria from insects

AIMS

Natural niches and transmission routes of lactic acid bacteria (LAB) are highly versatile. Proposed routes of transmission to food fermentations are from plant material via insects or vice versa. This study aimed to establish a method for the selective isolation of LAB from insects.

METHODS AND RESULTS

Varied parameters that influence growth and selectivity are temperature, type of carbohydrate and atmosphere. Additionally, effects of antibiotics to suppress non-LAB species were evaluated. A model consortium consisting of 12 species representing different lifestyles was inoculated in growth medium to identify conditions for highest diversity and recovery rate. The method was applied to isolate LAB from Drosophila melanogaster, Sitotroga cerealella, Tribolium castaneum and Tenebrio molitor. Isolated species were Leuconostoc mesenteroides, Paucilactobacillus vaccinostercus and Lactiplantibacillus plantarum from D. melanogaster and L. mesenteroides, Pediococcus pentosaceus and Latilactobacillus curvatus from T. molitor. No LAB could be isolated from T. castaneum and S. cerealella. 16S rDNA amplicon sequencing of DNA obtained from insects corroborated part of our results.

CONCLUSION

A combination of different enrichment conditions ensures a high probability to isolate LAB species from insects and can be helpful above already known non-cultivation methods.

SIGNIFICANCE AND IMPACT OF THE STUDY

The novel method allows to selectively isolate LAB from insects and the strategy of the method is of interest to study other niches.

Bombilactobacillus apium sp. nov., isolated from the gut of honeybee (Apis cerana)

A novel Gram-reaction positive-, catalase and oxidase negative-, rod-shaped, facultatively anaerobic bacterial strain, DCY120^T_, was isolated from the gut of honeybee (Apis cerana) in Gyeonggi-do, South Korea. Strain DCY120^T belongs to the genus Bombilactobacillus and is moderately related to Bombilactobacillus mellis Hon2^T (94.1% similarity), Bombilactobacillus bombi BTLCH M1/2^T (93.8%), and Bombilactobacillus mellifer Bin4N^T (93.5%) based on 16S rRNA gene sequence analysis. The genome of strain DCY120^T was sequenced and the average nucleotide identity (ANI) between strain DCY120^T and the related Bombilactobacillus type strains were below the threshold value (95-96%) for species delineation. The major fatty acids were C_16:0, C_18:1 ω9c, Summed C_19:1 ω6c/C_19:0 cyclo ω10c/C_19:0 ω6 and Summed C_18:1 ω7c/C_18:1 ω6c. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), one glycolipid (GL), and one unidentified aminophospholipid (APL). The amino acids in peptidoglycan of strain DCY120^T were lysine, alanine, glutamic acid, and aspartic acid. In conclusion, the description of phenotypic and genotypic properties support strain DCY120^T as a novel species within the genus Bombilactobacillus, for which the name Bombilactobacillus apium sp. nov. is proposed. The type strain is DCY120^T (= KCTC 43194^T = JCM 34006^T).

Proposal of Lactobacillus kosoi Chiou et al. 2018 as a later heterotypic synonym of Lactobacillus micheneri McFrederick et al. 2018, elevation of Lactobacillus plantarum subsp. argentoratensis to the species level as Lactobacillus argentoratensis sp. nov., and Lactobacillus zhaodongensis sp. nov., isolated from traditional Chinese pickle and the intestinal tract of a honey bee (Apis mellifera)

Lactobacillus kosoi Chiou et al. 2018 and Lactobacillus micheneri McFrederick et al. 2018 are closely related, and they share 100 % 16S rRNA gene sequence similarity, 99.6 % pheS gene sequence similarity, 100 % rpoA gene sequence similarity, 97.3 % average nucleotide identity (ANI) value and 76.6 % in silico DNA-DNA hybridization (isDDH) value, indicating that they represent the same species. Fatty acid methyl esters (FAME) analysis and phenotypic characterization also indicated that L. kosoi and L. micheneri are very similar. We propose L. kosoi Chiou et al. 2018 as a later heterotypic synonym of L. micheneri McFrederick et al. 2018. The taxonomic position of Lactobacillus plantarum subsp. argentoratensis in the L. plantarum group was re-examined using a polyphasic approach, including sequence analyses of 16S rRNA, pheS, rpoA and recA genes, average nucleotide identity analysis, in silico DNA-DNA hybridization, fatty acid methyl ester analysis and phenotypic characterization. Results of 16S rRNA gene sequence analysis indicated that L. plantarum subsp. argentoratensis was closely related to L. plantarum subsp. plantarum, L. pentosus and L. paraplantarum in the L. plantarum group, sharing 99.6-99.7 % 16S rRNA gene sequence similarities. Results of pheS, rpoA and recA gene sequence analyses indicated that L. plantarum subsp. argentoratensis was most closely related to L. plantarum subsp. plantarum, having 91.8 % pheS gene sequence similarity, 98.9 % rpoA gene sequence similarity and 93.1 % recA gene sequence similarity. L. plantarum subsp. argentoratensis DSM 16365^T shared 95.6 % ANI value and 62.9 % isDDH value with L. plantarum subsp. plantarum ATCC 14917^T. The low isDDH value confirmed that L. plantarum subsp. argentoratensis and L. plantarum subsp. plantarum represent two different species, rather than two different subspecies in the L. plantarum group. On the basis of the data from polyphasic characterization obtained in the present study and in previous studies, L. plantarum subsp. argentoratensis is elevated to the species level and represents a novel species of the genus Lactobacillus, for which the name Lactobacillus argentoratensis sp. nov. is proposed and the type strain is DKO 22^T (=CIP 108320^T=DSM 16365^T=JCM 16169^T). Two novel Gram-stain-positive bacterial strains, designated 1206-1^T and F027-1-2, were isolated from traditional pickle in Heilongjiang Province, PR China, and from the intestinal tract of a honey bee (Apis mellifera) in Hubei Province, PR China, respectively. The two bacteria were characterized by a polyphasic approach, including 16S rRNA gene sequence analysis, pheS gene sequence analysis, rpoA gene sequence analysis, fatty acid methyl ester analysis, average nucleotide identity analysis, in silico DNA-DNA hybridization analysis and an analysis of phenotypic features. The results of 16S rRNA gene sequence analysis indicated that strains 1206-1^T and F027-1-2 were distantly related to Lactobacillus sharpeae, Lactobacillus hulanensis, Lactobacillus songhuajiangensis, Lactobacillus pantheris, Lactobacillus thailandensis, Lactobacillus camelliae, Lactobacillus jixianensis, Lactobacillus nasuensis, Lactobacillus baoqingensis, Lactobacillus manihotivorans and Lactobacillus porcinae. Strain 1206-1^T exhibited 94.2-96.4 % 16S rRNA gene sequence similarities, 69.5-83.3 % pheS gene sequence similarities and 73.1-90.3 % rpoA gene sequence similarities to type strains of phylogenetically related species. ANI and isDDH values between strain 1206-1^T and the type strains of phylogenetically related species were 52.7-73.7 % and 21.1-30.1 %, respectively. On the basis of the data obtained in the present study, a novel species, Lactobacillus zhaodongensis sp. nov. is proposed and the type strain is 1206-1^T (=CCM 8981^T=CCTCC AB 2019200^T=LMG 31620^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 panisapium sp. nov., from honeybee Apis cerana bee bread

A novel facultatively anaerobic, Gram-stain-positive, non-motile, non-spore-forming, catalase-negative bacterium of the genus Lactobacillus, designated strain Bb 2-3^T, was isolated from bee bread of Apis cerana collected from a hive in Kunming, China. The strain was regular rod-shaped. Optimal growth occurred at 37 °C, pH 6.5 with 5.0 g l⁻¹ NaCl. The predominant fatty acids were C_18 : 1ω9c, C_16 : 0 and C_19 : 0 iso. Respiratory quinones were not detected. Seven glycolipids, three lipids, phosphatidylglycerol and diphosphatidylglycerol were detected. The peptidoglycan type A4α l-Lys-d-Asp was determined. Strain Bb 2-3^T was closely related to Lactobacillus bombicola DSM 28793^T, Lactobacillus apis LMG 26964^T and Lactobacillus helsingborgensis DSM 26265^T, with 97.8, 97.6 and 97.0 % 16S rRNA gene sequence similarity, respectively. A comparison of two housekeeping genes, rpoA and pheS, revealed that strain Bb 2-3^T was well separated from the reference strains of species of the genus Lactobacillus. The average nucleotide identity between strain Bb 2-3^T and the type strains of closely related species was lower than the 95–96 % threshold value for delineation of genomic prokaryotic species. The G+C content of the genomic DNA of strain Bb 2-3^T was 37.4 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain Bb 2-3^T is proposed to represent a novel species of the genus Lactobacillus, for which we propose the name Lactobacillus panisapium sp. nov. The type strain is Bb 2-3^T (=DSM 102188^T=ACCC 19955^T).