Lactiplantibacillus argentoratensis AGMB00912 alleviates diarrhea and promotes the growth performance of piglets during the weaning transition.

BACKGROUND: Preventing post-weaning diarrhea (PWD) in weaned piglets is a crucial challenge in the swine production industry. The stress of weaning, dietary shifts from maternal milk to solid feed, and environmental changes lead to decreased microbial diversity, increased pathogen abundance, and compromised intestinal integrity. We have previously identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces, which demonstrated antimicrobial activity against pathogens and enhanced short-chain fatty acid production. This research aimed to evaluate the efficacy of LA strain supplementation as a strategy to inhibit PWD and enhance overall growth performance in weaned piglets. RESULTS: LA supplementation in weaned piglets significantly increased body weight gain, average daily gain, and average daily feed intake. It also alleviated diarrhea symptoms (diarrhea score and incidence). Notably, LA was found to enrich beneficial microbial populations (Lactobacillus, Anaerobutyricum, Roseburia, Lachnospiraceae, and Blautia) while reducing the abundance of harmful bacteria (Helicobacter and Campylobacter). This not only reduces the direct impact of pathogens but also improves the overall gut microbiota structure, thus enhancing the resilience of weaned piglets. LA treatment also promotes the growth of the small intestinal epithelial structure, strengthens gut barrier integrity, and increases short-chain fatty acid levels in the gut. CONCLUSIONS: The study findings demonstrate the promising potential of LA in preventing PWD. Supplementation with the LA strain offers a promising feed additive for improving intestinal health and growth in piglets during the weaning transition, with the potential to significantly reduce the incidence and severity of PWD.

Lactiplantibacillus argentoratensis AGMB00912 protects weaning mice from ETEC infection and enhances gut health.

Maintaining a healthy intestinal environment, optimal epithelial barrier integrity, and balanced gut microbiota composition are essential for the growth performance of weaning pigs. We identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces as having antimicrobial activity against pathogens and enhanced short-chain fatty acid (SCFA) production. Herein, we assess the protective role of LA using a weaning mouse model with enterotoxigenic Escherichia coli (ETEC) infection. LA treatment improves feed intake and weight gain and alleviates colon shortening. Furthermore, LA inhibits intestinal damage, increases the small intestine villus height compared with the ETEC group, and enhances SCFA production. Using the Kyoto Encyclopedia of Genes and Genomes and other bioinformatic tools, including InterProScan and COGNIZER, we validated the presence of SCFA-producing pathways of LA and Lactiplantibacillus after whole genome sequencing. LA mitigates ETEC-induced shifts in the gut microbiota, decreasing the proportion of Escherichia and Enterococcus and increasing SCFA-producing bacteria, including Kineothrix, Lachnoclostridium, Roseuburia, Lacrimispora, Jutongia, and Blautia. Metabolic functional prediction analysis revealed enhanced functions linked to carbohydrate, amino acid, and vitamin biosynthesis, along with decreased functions associated with infectious bacterial diseases compared to the ETEC group. LA mitigates the adverse effects of ETEC infection in weaning mice, enhances growth performance and intestinal integrity, rebalances gut microbiota, and promotes beneficial metabolic functions. These findings validate the functionality of LA in a small animal model, supporting its potential application in improving the health and growth performance of weaning pigs.

Lactiplantibacillus argentoratensis AGMB00912 alleviates salmonellosis and modulates gut microbiota in weaned piglets: a pilot study.

This study aimed to evaluate the efficacy of Lactiplantibacillus argentoratensis AGMB00912 (LA) in reducing Salmonella Typhimurium infection in weaned piglets. The investigation focused on the influence of LA on the gut microbiota composition, growth performance, and Salmonella fecal shedding. The results indicated that LA supplementation significantly improved average daily gain and reduced the prevalence and severity of diarrhea. Fecal analysis revealed reduced Salmonella shedding in the LA-supplemented group. Furthermore, LA notably altered the composition of the gut microbiota, increasing the levels of beneficial Bacillus and decreasing those of harmful Proteobacteria and Spirochaetes. Histopathological examination showed less intestinal damage in LA-treated piglets than in the controls. The study also observed that LA affected metabolic functions related to carbohydrate, amino acid, and fatty acid metabolism, thereby enhancing gut health and resilience against infection. Short-chain fatty acid concentrations in the feces were higher in the LA group, suggesting improved gut microbial activity. LA supplementation enriched the population of beneficial bacteria, including Streptococcus, Clostridium, and Bifidobacterium, while reducing the number of harmful bacteria, such as Escherichia and Campylobacter. These findings indicate the potential of LA as a probiotic alternative for swine nutrition, offering protective effects to the gut microbiota against Salmonella infection.

Novel microbiota Mesosutterella faecium sp. nov. has a protective effect against inflammatory bowel disease.

A novel Gram-negative, obligate anaerobe, non-motile, flagella-lacking, catalase- and oxidase-negative, coccobacilli-shaped bacterial strain designated AGMB02718T was isolated from swine feces. The 16S rRNA gene analysis indicated that strain AGMB02718T belonged to the genus Mesosutterella with the highest similarity to M. multiformis 4NBBH2T (= DSM 106860T) (sequence similarity of 96.2%), forming a distinct phylogenetic lineage. Its growth occurred at 25-45°C (optimal 37°C) and in 0.5-1% NaCl (optimal 0.5%). Strain AGMB02718T was asaccharolytic and contained menaquinone 6 (MK-6) and methylmenaquinone 6 (MMK-6) as the predominant respiratory quinones. The major cellular fatty acids in the isolate were C18:1ω9c and C16:0. Based on the whole-genome sequencing analysis, strain AGMB02718T had a 2,606,253 bp circular chromosome with a G + C content of 62.2%. The average nucleotide identity value between strain AGMB02718T and M. multiformis 4NBBH2T was 72.1%, while the digital DNA-DNA hybridization value was 20.9%. Interestingly, genome analysis suggested that strain AGMB02718T possessed a low-toxicity lipopolysaccharide (LPS) because the genome of the isolate does not include lpxJ and lpxM genes for Kdo2-Lipid A (KLA) assembly, which confers high toxicity to LPS. Moreover, in vitro macrophage stimulation assay confirmed that AGMB02718T produced LPS with low toxicity. Because the low-toxicity LPS produced by the Sutterellaceae family is involved in regulating host immunity and low-toxicity LPS-producing strains can help maintain host immune homeostasis, we evaluated the anti-inflammatory activity of strain AGMB02718T against inflammatory bowel disease (IBD). As a result, strain AGMB02718T was able to prevent the inflammatory response in a dextran sulfate sodium (DSS)-induced colitis model. Therefore, this strain represents a novel species of Mesosutterella that has a protective effect against DSS-induced colitis, and the proposed name is Mesosutterella faecium sp. nov. The type strain is AGMB02718T (=GDMCC 1.2717T = KCTC 25541T).

Phocaeicola acetigenes sp. nov., producing acetic acid and iso-butyric acid, isolated faeces from a healthy human.

An obligately anaerobic, non-motile, Gram-stain-negative, and rod-shaped strain KGMB11183T was isolated from the feces of healthy Koreans. The growth of strain KGMB11183T occurred at 30-45 °C (optimum 37 °C), at pH 6-9 (optimum pH 7), and in the presence of 0-0.5% NaCl (optimum 0%). Strain KGMB11183T showed 16S rRNA gene sequence similarities of 95.4% and 94.2% to the closest recognized species, Phocaeicola plebeius M12T, and Phocaeicola faecicola AGMB03916T. Phylogenetic analysis showed that strain KGMB11183T is a member of the genus Phocaeiocla. The major end products of fermentation are acetic acid and isobutyric acid. The major cellular fatty acids (> 10%) of this isolate were C18:1 cis 9, anteiso-C15:0, and summed feature 11 (iso-C17:0 3-OH and/or C18:2 DMA). The assembled draft genome sequences of strain KGMB11183T consisted of 3,215,271 bp with a DNA G + C content of 41.4%. According to genomic analysis, strain KGMB11183T has a number of genes that produce acetic acid. The genome of strain KGMB11183T encoded the starch utilization system (Sus) operon, SusCDEF suggesting that strain uses many complex polysaccharides that cannot be digested by humans. Based on the physiological, chemotaxonomic, phenotypic, and phylogenetic data, strain KGMB11183T is regarded a novel species of the genus Phocaeicola. The type strain is KGMB11183T (= KCTC 25284T = JCM 35696T).

Optimizing protein crosslinking control: Synergistic quenching effects of glycine, histidine, and lysine on glutaraldehyde reactions.

Glutaraldehyde (GA) is a protein crosslinker widely used in biochemical and pharmaceutical research because it can rapidly stabilize and immobilize substrates via amine group interactions. However, controlling GA crosslinking is challenging owing to its swift reactivity and the influence of various solution conditions, such as pH and concentrations of the substrate and crosslinker. Although extensive research has focused on GA cross-linking mechanisms, studies on quenching, which is critical for preventing non-specific aggregation during prolonged storage, remain sparse. This study examines the quenching efficiency of a combined amino acid mixture of glycine, histidine, and lysine, which are commonly used as individual quenchers. Our findings, confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis, demonstrate that this amino acid blend offers superior quenching compared to single amino acids, enhancing quenching activity across a wide pH spectrum. These results provide a novel approach for mitigating the high reactivity of GA with implications for improving sample preservation and stabilization in a range of biochemical applications, including microscopy and cell fixation.

Pseudoxanthomonas sp. JBR18, a halotolerant endophytic bacterium, improves the salt tolerance of Arabidopsis seedlings.

Salinization of land is globally increasing due to climate change, and salinity stress is an important abiotic stressor that adversely affects agricultural productivity. In this study, we assessed a halotolerant endophytic bacterium, Pseudoxanthomonas sp. JBR18, for its potential as a plant growth-promoting agent with multiple beneficial properties. The strain exhibited tolerance to sodium chloride concentration of up to 7.5 % in the R2A medium. In vitro evaluation revealed that strain JBR18 possessed proteolytic, protease (EC 3.4), and cellulase (EC 3.2.1.4) activities, as well as the ability to produce indole-acetic acid, proline, and exopolysaccharides. Compared with the controls, co-cultivation of Arabidopsis seedlings with the strain JBR18 improved plant growth, rosette size, shoot and root fresh weight, and chlorophyll content under salinity stress. Moreover, JBR18-inoculated seedlings showed lower levels of malondialdehyde, reactive oxygen species, and Na+ uptake into plant cells under salt stress but higher levels of K+. Additionally, seedlings inoculated with JBR18 exhibited a delayed response time and quantity of salt-responsive genes RD29A, RD29B, RD20, RD22, and KIN1 under salt stress. These multiple effects suggest that Pseudoxanthomonas sp. JBR18 is a promising candidate for mitigating the negative impacts of salinity stress on plant growth. Our findings may assist in future efforts to develop eco-friendly strategies for managing abiotic stress and enhancing plant tolerance to salt stress.

Gordonibacter faecis sp. nov., producing urolithin C from ellagic acid, isolated from feces of healthy Korean subjects.

A Gram-stain-positive, anaerobic, motile, and short rod-shaped bacterium, designated KGMB12511T, was isolated from the feces of healthy Koreansubjects. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain KGMB12511T was closely related to Gordonibacter pamelaeae 7-10-1-bT (95.2%). The draft genome of KGMB12511T comprised 33 contigs and 2,744 protein-coding genes. The DNA G + C content was 59.9% based on whole-genome sequences. The major cellular fatty acids (>10%) of strain KGMB12511T were C18:1 cis9, C18:1 cis9 DMA (dimethylacetal), and C16:0 DMA. The predominant polar lipids included a diphosphatydilglycerol, four glycolipids, and an unidentified phospholipid. The major respiratory quinones were menaquinone 6 (MK-6) and monomethylmenaquinone 6 (MMK-6). Furthermore, HPLC analysis demonstrated the ability of strain KGMB12511T to convert ellagic acid into urolithin. Based on a comprehensive analysis of phenotypic, chemotaxonomic, and phylogenetic data, strain KGMB12511T represents a novel species in the genus Gordonibacter. The type strain is KGMB12511T (= KCTC 25343T = NBRC 116190T).

Characteristics of Lactococcus petauri GB97 lysate isolated from porcine feces and its in vitro and in vivo effects on inflammation, intestinal barrier function, and gut microbiota composition in mice.

IMPORTANCE: Weaning is a crucial step in piglet management to improve pork production. During the weaning phase, disruption of epithelial barrier function and intestinal inflammation can lead to decreased absorption of nutrients and diarrhea. Therefore, maintaining a healthy intestine, epithelial barrier function, and gut microbiota composition in this crucial phase is strategic for optimal weaning in pigs. We isolated a lysate of Lactococcus petauri GB97 (LPL97) from healthy porcine feces and evaluated its anti-inflammatory activities, barrier integrity, and gut microbial changes in LPS-induced murine macrophages and DSS-induced colitis mice. We found that LPL97 regulated the immune response by downregulating the TLR4/NF-κB/MAPK signaling pathway both in vitro and in vivo. Furthermore, LPL97 alleviated the disruption of intestinal epithelial integrity and gut microbiota dysbiosis in colitis mice. This study indicates that LPL97 has the potential to be developed as an alternative feed additive to antibiotics for the swine industry.

Anti-obesity activity of human gut microbiota Bacteroides stercoris KGMB02265.

Obesity is a global health threat that causes various complications such as type 2 diabetes and nonalcoholic fatty liver disease. Gut microbiota is closely related to obesity. In particular, a higher Firmicutes to Bacteroidetes ratio has been reported as a biomarker of obesity, suggesting that the phylum Bacteroidetes may play a role in inhibiting obesity. Indeed, the genus Bacteroides was enriched in the healthy subjects based on metagenome analysis. In this study, we determined the effects of Bacteroides stercoris KGMB02265, a species belonging to the phylum Bacteroidetes, on obesity both in vitro and in vivo. The cell-free supernatant of B. stercoris KGMB02265 inhibited lipid accumulation in 3T3-L1 preadipocytes, in which the expression of adipogenic marker genes was repressed. In vivo study showed that the oral administration of B. stercoris KGMB02265 substantially reduced body weight and fat weight in high-fat diet induced obesity in mice. Furthermore, obese mice orally administered with B. stercoris KGMB02265 restored glucose sensitivity and reduced leptin and triglyceride levels. Taken together, our study reveals that B. stercoris KGMB02265 has anti-obesity activity and suggests that it may be a promising candidate for treating obesity.

Sphingomonas abietis sp. nov., an Endophytic Bacterium Isolated from Korean Fir.

PAMB 00755T, a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20°C, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755T was most closely related to Sphingomonas chungangi MAH-6T (97.7%) and Sphingomonas polyaromaticivorans B2-7T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9-81.3%), average amino acid identity (73.3-75.9%), and digital DNA-DNA hybridization (73.3-75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C18:1ω7c and/or C18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755T as the type strain (= KCTC 92781T = GDMCC 1.3779T).

Collinsella urealyticum sp. nov., a urease-positive bacterial strain isolated from swine faeces.

A novel actinobacterial strain, designated AGMB00827T, was isolated from swine faeces. Strain AGMB00827T was obligately anaerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped bacterium. Comparative analyses based on the 16S rRNA gene and whole genome sequence revealed that strain AGMB00827T was affiliated to the genus Collinsella, and was most closely related to Collinsella vaginalis Marseille-P2666T (= KCTC 25056T). Biochemical analysis showed strain AGMB00827T was negative for catalase and oxidase. Interestingly, strain AGMB00827T possessed urease activity, which was determined by traditional methods (API test and Christensen's urea medium), unlike related strains. Furthermore, the major cellular fatty acids (> 10%) of the isolate were C18:1 ω9c, C16:0, C16:0 DMA and C18:2 ω9,12c DMA. Based on the whole genome sequence analysis, the DNA G + C content of strain AGMB00827T was 52.3%, and the genome size and numbers of rRNA and tRNA genes were 1,945,251 bp, 3 and 46, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain AGMB00827T and C. vaginalis KCTC 25056 T were 71.0 and 23.2%, respectively. Additionally, the genome analysis revealed that strain AGMB00827T possesses urease gene cluster including ureABC and ureDEFG while the related strains do not have those genes, which is consistent with the urease activity. On the basis of polyphasic taxonomic approach, strain AGMB00827T represents a novel species within the genus Collinsella, for which the name Collinsella urealyticum sp. nov. is proposed. The type strain is AGMB00827T (= KCTC 25287T = GDMCC 1.2724T).

Abietane Diterpenoids Isolated from Torreya nucifera Disrupt Replication of Influenza Virus by Blocking the Phosphatidylinositol-3-Kinase (PI3K)-Akt and ERK Signaling Pathway.

Although vaccines and antiviral drugs are available, influenza viruses continue to pose a significant threat to vulnerable populations globally. With the emergence of drug-resistant strains, there is a growing need for novel antiviral therapeutic approaches. We found that 18-hydroxyferruginol (1) and 18-oxoferruginol (2) isolated from Torreya nucifera exhibited strong anti-influenza activity, with 50% inhibitory concentration values of 13.6 and 18.3 µM against H1N1, 12.8 and 10.8 µM against H9N2, and 29.2 µM (only compound 2) against H3N2 in the post-treatment assay, respectively. During the viral replication stages, the two compounds demonstrated stronger inhibition of viral RNA and protein in the late stages (12-18 h) than in the early stages (3-6 h). Moreover, both compounds inhibited PI3K-Akt signaling, which participates in viral replication during the later stages of infection. The ERK signaling pathway is also related to viral replication and was substantially inhibited by the two compounds. In particular, the inhibition of PI3K-Akt signaling by these compounds inhibited viral replication by sabotaging influenza ribonucleoprotein nucleus-to-cytoplasm export. These data indicate that compounds 1 and 2 could potentially reduce viral RNA and viral protein levels by inhibiting the PI3K-Akt signaling pathway. Our results suggest that abietane diterpenoids isolated from T. nucifera may be potent antiviral candidates for new influenza therapies.

Parabacteroides faecalis sp. nov. Isolated from Swine Faeces.

A Gram-negative, obligate anaerobic, non-motile, non-spore-forming, rod-shaped bacterial strain designated AGMB00274T was isolated from swine faeces. An 16S rRNA gene analysis indicated that strain AGMB00274T belonged to the genus Parabacteroides, with the highest similarity to Parabacteroides johnsonii (P. johnsonii) DSM 18315T (sequence similarity of 94.9%). The genome size of strain AGMB00274T was 4,308,683 bp, with a DNA G+C content of 42.5 mol%. The biochemical analysis of strain AGMB00274T showed that it was positive for gelatin hydrolysis and α-fucosidase, but negative for the acid production from D-glucose, D-mannitol, D-maltose, salicin, glycerol, D-cellobiose, D-mannose, D-melezitose, D-sorbitol, D-trehalose, and negative for α-arabinosidase, glutamic acid decarboxylase, and pyroglutamic acid arylamidase. The dominant cellular fatty acids (> 10%) of the isolate were anteiso-C15: 0 (23.2%), iso-C15: 0 (16.6%), C18: 1 ω9c (16.4%), summed feature 11 (iso-C17: 0 3-OH and/or C18: 2 DMA) (12.5%), and C16: 0 (11.3%). The major respiratory quinones of strain AGMB00274T were MK-9 (55.4%) and MK-10 (44.6%). The major polar lipid was phosphatidylethanolamine. Based on phylogenetic, genetic, physiological, and chemotaxonomic analyses, as a novel species of the genus Parabacteroides, strain AGMB00274T was proposed with the name Parabacteroides faecalis sp. nov. The type strain used was AGMB00274T (= KCTC 25286T = GDMCC 1.2742T).

ECM-targeting bacteria enhance chemotherapeutic drug efficacy by lowering IFP in tumor mouse models.

Bacterial cancer therapies aim to manipulate bacteria to effectively deploy therapeutic payloads to tumors. Attenuated bacteria alone often cannot eradicate solid tumors. Attenuated Salmonella can be engineered to deliver cytotoxic drugs to either trigger an immune response or increase antitumor efficacy when combined with chemotherapeutic drugs. However, the extracellular matrix (ECM) surrounding cancer cells forms a barrier that often limits the ability of chemotherapeutic and cytotoxic drugs to penetrate and eliminate tumors. To overcome this limitation, we developed a strategy to combine chemotherapy with an attenuated Salmonella typhimurium strain engineered to secrete HysA protein (from Staphylococcus aureus; Hyaluronidase, HAase) in tumors. The engineered Salmonella effectively degraded hyaluronan (HA), which is a major ECM constituent in tumors, and suppressed tumor growth in mouse models of pancreatic adenocarcinoma (ASPC-1) and breast cancer (4T1). Furthermore, it prolonged survival when combined with chemotherapeutic drugs (doxorubicin or gemcitabine). Upon bacterial colonization, the HAase-mediated ECM degradation decreased interstitial fluid pressure (IFP) in the tumor microenvironment. Additionally, HA degradation using HAase-expressing bacteria in vivo led to decreased binding to the receptor, CD44, expressed in tumors. This may modulate proliferation- and apoptosis-related signal pathways. Therefore, ECM-targeting bacteria can be used as a synergistic anticancer therapeutic agent to maximize chemotherapeutic drug delivery into highly invasive tumors.

A nostoxanthin-producing bacterium, Sphingomonas nostoxanthinifaciens sp. nov., alleviates the salt stress of Arabidopsis seedlings by scavenging of reactive oxygen species.

A novel, nostoxanthin-producing, endophytic bacterium, designated as AK-PDB1-5T, was isolated from the needle-like leaves of the Korean fir (Abies koreana Wilson) collected from Mt. Halla in Jeju, South Korea. A 16S rRNA sequence comparison indicated that the closest phylogenetic neighbors were Sphingomonas crusticola MIMD3T (95.6%) and Sphingomonas jatrophae S5-249T (95.3%) of the family Sphingomonadaceae. Strain AK-PDB1-5T had a genome size of 4,298,284 bp with a 67.8% G + C content, and digital DNA-DNA hybridization and OrthoANI values with the most closely related species of only 19.5-21% and 75.1-76.8%, respectively. Cells of the strain AK-PDB1-5T were Gram-negative, short rods, oxidase- and catalase-positive. Growth occurred at pH 5.0-9.0 (optimum pH 8.0) in the absence of NaCl at 4-37°C (optimum 25-30°C). Strain AK-PDB1-5T contained C14:0 2OH, C16:0 and summed feature 8 as the major cellular fatty acids (> 10%), while sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phospholipids and lipids were found to be the major polar lipids. The strain produces a yellow carotenoid pigment; natural products prediction via AntiSMASH tool found zeaxanthin biosynthesis clusters in the entire genome. Biophysical characterization by ultraviolet-visible absorption spectroscopy and ESI-MS studies confirmed the yellow pigment was nostoxanthin. In addition, strain AK-PDB1-5T was found significantly promote Arabidopsis seedling growth under salt conditions by reducing reactive oxygen species (ROS). Based on the polyphasic taxonomic analysis results, strain AK-PDB1-5T was determined to be a novel species in the genus Sphingomonas with the proposed name Sphingomonas nostoxanthinifaciens sp. nov. The type strain is AK-PDB1-5T (= KCTC 82822T = CCTCC AB 2021150T).

Genome insights into the plant growth-promoting bacterium Saccharibacillus brassicae ATSA2T.

Endophytes can facilitate the improvement of plant growth and health in agriculturally important crops, yet their genomes and secondary metabolites remain largely unexplored. We previously isolated Saccharibacillus brassicae strain ATSA2T from surface-sterilized seeds of kimchi cabbage and represented a novel species of the genus Saccharibacillus. In this study, we evaluated the plant growth-promoting (PGP) effect of strain ATSA2T in kimchi cabbage, bok choy, and pepper plants grown in soils. We found a significant effect on the shoot and root biomass, and chlorophyll contents following strain ATSA2T treatment. Strain ATSA2T displayed PGP traits such as indole acetic acid (IAA, 62.9 µg/mL) and siderophore production, and phosphate solubilization activity. Furthermore, genome analysis of this strain suggested the presence of gene clusters involved in iron acquisition (fhuABD, afuABC, fbpABC, and fepCDG) and phosphate solubilization (pstABCHS, phoABHLU, and phnCDEP) and other phytohormone biosynthesis genes, including indole-3-acetic acid (trpABCDEFG), in the genome. Interestingly, the secondary metabolites cerecidin, carotenoid, siderophore (staphylobactin), and bacillaene underlying plant growth promotion were found in the whole genome via antiSMASH analysis. Overall, physiological testing and genome analysis data provide comprehensive insights into plant growth-promoting mechanisms, suggesting the relevance of strain ATSA2T in agricultural biotechnology.

Caproiciproducens faecalis sp. nov., Isolated from Cow Faeces.

The bacterial strain AGMB10547T was isolated from cow faeces deposited by the National Institute of Animal Science in Cheonan, Republic of Korea. The strain AGMB10547T possessed the phenotypic, biochemical and chemotaxonomic characteristics of the bacteria of the family Oscillospiraceae. The isolate was obligately anaerobic, non-motile, Gram-positive and rod-shaped bacteria. The growth of strain AGMB10547T occurred within 35-40 °C (optimum at 37 °C), at pH 6-7 (optimum of 7) and in the presence of 0.5-2.0% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, strain AGMB10547T belonged to the genus Caproiciproducens and was most closely related to Caproiciproducens galactitolivorans BS-1T (96.9%). The DNA G+C content was 49.0 mol%. The major cellular fatty acids (> 10%) of the isolate were C14:0, C14:0 DMA, C16:1 ω9c and C16:0. The average nucleotide identity (ANI) and digital DNA-DNA Hybridization (dDDH) values between strain AGMB10547T and C. galactitolivorans BS-1T were 75.5% and 19.2%. Based on the phenotypic, genotypic, biochemical and chemotaxonomic analyses, strain AGMB10547T represents a novel species of the genus Caproiciproducens, for which the name Caproiciproducens faecalis sp. nov. is proposed. The type strain AGMB10547T (=KCTC 25200T=NBRC 115006T=GDMCC 1.2575T).

Exploring the Microbial Community and Functional Characteristics of the Livestock Feces Using the Whole Metagenome Shotgun Sequencing.

The foodborne illness is the important public health concerns, and the livestock feces are known to be one of the major reservoirs of foodborne pathogens. Also, it was reported that 45.5% of foodborne illness outbreaks have been associated with the animal products contaminated with the livestock feces. In addition, it has been known that the persistence of a pathogens depends on many potential virulent factors including the various virulent genes. Therefore, the first step to understanding the public health risk of livestock feces is to identify and describe microbial communities and potential virulent genes that contribute to bacterial pathogenicity. We used the whole metagenome shotgun sequencing to evaluate the prevalence of foodborne pathogens and to characterize the virulence associated genes in pig and chicken feces. Our data showed that the relative abundance of potential foodborne pathogens, such as Bacillus cereus was higher in chickens than pigs at the species level while the relative abundance of foodborne pathogens including Campylobacter coli was only detected in pigs. Also, the microbial functional characteristics of livestock feces revealed that the gene families related to "Biofilm formation and quorum sensing" were highly enriched in pigs than chicken. Moreover, the variety of gene families associated with "Resistance to antibiotics and toxic compounds" were detected in both animals. These results will help us to prepare the scientific action plans to improve awareness and understanding of the public health risks of livestock feces.

Gut Microbiota Eubacterium callanderi Exerts Anti-Colorectal Cancer Activity.

The gut microbiota (GM) is associated with colorectal cancer (CRC) development. However, studies demonstrating the role of GM in CRC are limited to metagenomic analyses. These studies lack direct evidence proving that the candidate strains are involved in CRC, and isolated probiotics for bacteriotherapy. Therefore, to identify novel GM with anti-CRC activity, we previously isolated gut bacteria from the feces of healthy individuals, screened the isolated GM's anti-CRC activity, and discovered that cell-free supernatants of GM isolates demonstrated antiproliferative activity against CRC cells. Here, our study identified one of them as Eubacterium callanderi and chose it for further study because the genus Eubacterium has been suggested to contribute to various aspects of gut health; however, the functions are unknown. First, we confirmed that E. callanderi cell-free supernatant (EcCFS) exerted antiproliferative activity-by inducing apoptosis and cell cycle arrest-that was dose-dependent and specific to cancer cell lines. Next, we discovered that EcCFS active molecules were heat stable and protease insensitive. High-performance liquid chromatography analysis revealed that EcCFS contained high butyrate concentrations possessing anticancer activity. Additionally, gas chromatography-mass spectrometry analysis of the aqueous phase of ethyl acetate-extracted EcCFS and an antiproliferation assay of the aqueous phase and 4-aminobutanoic acid (GABA) suggested that GABA is a possible anti-CRC agent. Finally, in the CT26 allograft mouse model, E. callanderi oral administration and EcCFS peri-tumoral injection inhibited tumor growth in vivo. Therefore, our study reveals that E. callanderi has an anti-CRC effect and suggests that it may be a potential candidate for developing probiotics to control CRC. IMPORTANCE The gut microbiota has been reported to be involved in colorectal cancer, as suggested by metagenomic analysis. However, metagenomic analysis has limitations, such as bias in the analysis and the absence of bacterial resources for follow-up studies. Therefore, we attempted to discover gut microorganisms that are related to colorectal cancer using the culturomics method. In this study, we discovered that Eubacterium callanderi possesses anti-colorectal cancer activity in vitro and in vivo, suggesting that E. callanderi could be used in bacteriotherapy for colorectal cancer treatment.