Tailocins are nano-scale phage tail-like protein complexes that can mediate antagonistic interactions between closely related bacterial species. While the capacity to produce R-type tailocin was found widely across Gammaproteobacteria, the production of F-type tailocins seems comparatively rare. In this study, we examined the freshwater isolate, Pragia fontium 24613, which can produce both R- and F-type tailocins. We investigated their inhibition spectrum, focusing on clinically relevant enterobacteria, and identified the associated tailocin gene cluster. Transmission electron microscopy confirmed that inactivation of the tape measure protein within the tailocin cluster disrupted R-tailocin production. Comparative analysis of Budviciaceae gene clusters showed high conservation of R-type tailocin genes, whereas F-type tailocin genes were found in only a few species, with little conservation. Our findings indicate a high prevalence of bacteriocin production among underexplored Enterobacteriales species. Detected tailocins showed potential as antimicrobials targeting clinically significant pathogens.
The growth and accumulation of active ingredients of Angelica sinensis were affected by rhizosphere soil microbial communities and soil environmental factors. However, the correlationship between growth and active ingredients and soil biotic and abiotic factors is still unclear. This study explored rhizosphere soil microbial community structures, soil physicochemical properties, enzyme activities, and their effects on the growth and active ingredient contents of A. sinensis in three principal cropping areas. Results indicated that the growth indices, ligustilide, ferulic acid contents, and soil environmental factors varied in cropping areas. Pearson correlation analysis revealed that the growth of A. sinensis was affected by organic matter, total nitrogen, total phosphorus, and available phosphorus; ferulic acid and ligustilide accumulation were related to soil catalase and alkaline phosphatase activities, respectively. Illumina MiSeq sequencing showed that the genera Mortierella and Conocybe were the dominant fungal communities, and Sphingomonas, Pseudomonas, Bryobacter, and Lysobacter were the main bacterial communities associated with the rhizosphere soil. Kruskal-Wallis one-way ANOVA and Spearman correlation conjoint analysis demonstrated a significant positive correlation (p < 0.001) among the composition of the rhizosphere microbial communities at all three sampling sites. The growth and active ingredient accumulation of A. sinensis not only was significantly susceptible to the bacterial communities of Sphingomonas, Epicoccum, Marivita, Muribaculum, and Gemmatimonas but also were significantly influenced by the fungal communities of Inocybe, Septoria, Tetracladium, and Mortierella (p < 0.05). Our findings provide a scientific basis for understanding the relationship between the growth and active ingredients in A. sinensis and their corresponding rhizosphere soil microbial communities, soil physicochemical properties, and enzyme activities.
- MeSH
- Angelica sinensis * growth & development chemistry microbiology MeSH
- Bacteria classification genetics isolation & purification MeSH
- Nitrogen analysis MeSH
- Phosphorus analysis MeSH
- Fungi classification genetics isolation & purification MeSH
- Microbiota * MeSH
- Soil chemistry MeSH
- Soil Microbiology * MeSH
- Rhizosphere * MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- China MeSH
The present study has undertaken the isolation of marine yeasts from mangrove sediment samples and their ability to produce alkaline protease enzymes. A total of 14 yeast isolates were recovered on yeast-malt agar (YMA) and yeast extract peptone dextrose (YEPD) agar medium. After screening for proteolytic activity on skim milk agar, marine yeast isolate, AKB-1 exhibited a hydrolysis zone of 18 mm. Optimal conditions for the enzyme production from yeast isolate AKB-1 were at 30 °C, pH 8, fructose as carbon source, potassium nitrate as nitrogen source, and 25% saline concentration. Under the optimal conditions, the protease enzyme activity of the isolate AKB-1 was observed to be 978 IU/mL. The structural and functional analysis was carried out through FTIR and HPLC analysis for the extracted protease enzyme. Furthermore, the enzyme produced was partially purified by solvent extraction using ethyl acetate and ammonium sulfate precipitation (3.4-fold) followed by dialysis (56.8-fold). The molecular weight of the purified enzyme was observed to be around 60 kDa using SDS-PAGE. The extracted protein showed good antibacterial activity against six different clinical bacterial pathogens and the highest against Bacillus cereus (16 ± 0.5 mm). The extracted protease enzyme was revealed to remove blood stains from cloth within 20 min of application similar to the commercial detergent. The marine yeast isolate was further identified as Candida orthopsilosis AKB-1 (Accession number KY348766) through 18S rRNA sequencing, and a phylogenetic tree was generated.
- MeSH
- Anti-Bacterial Agents pharmacology metabolism chemistry isolation & purification MeSH
- Bacillus cereus drug effects MeSH
- Bacterial Proteins * chemistry pharmacology metabolism isolation & purification MeSH
- Candida * enzymology isolation & purification genetics classification MeSH
- Endopeptidases * chemistry metabolism isolation & purification pharmacology MeSH
- Phylogeny MeSH
- Geologic Sediments microbiology MeSH
- Hydrogen-Ion Concentration MeSH
- Culture Media chemistry MeSH
- Microbial Sensitivity Tests MeSH
- Molecular Weight MeSH
- Enzyme Stability MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
A novel Gram-stain-negative, strictly aerobic, rod-shaped, light-yellow-pigmented, and chemo-organoheterotrophic bacterium, designated DF-77T, was isolated from dense mats of filamentous algae collected in March 2004 at Okinawa in Japan. The microorganism grew at 0-2.0% NaCl concentrations (w/v), pH 6.0-9.0, and 20-30 °C. The 16S rRNA gene sequence-based phylogenetic tree demonstrated that the strain DF-77T is a novel member of the family Flavobacteriaceae and was greatly related to Flagellimonas nanhaiensis SM1704T with sequence similarity of 95.5%. The main fatty acids were iso-C15:1 G, iso-C15:0, and iso-C17:0 3-OH, and the only isoprenoid quinone was menaquinone-6. The dominant polar lipids were phosphatidylethanolamine, two unidentified aminolipids, an unidentified phosphoaminolipid, and four unidentified lipids. The genome size of strain DF-77T was 3.60 Mbp with a DNA G + C content of 47.5%. The average nucleotide identity (ANI) value between the genomes of strain DF-77T and its closely related species was 69.8-70.7%. The digital DNA - DNA hybridization (dDDH) value of strain DF-77T with the strain of F. nanhaiensis SM1704T was 16.8%. The genome of the strain DF-77T revealed that it encoded several genes involved in bio-macromolecule degradation, indicating a high potential for producing industrially useful enzymes. Consequently, the strain is described as a new species in the genus Flagellimonas, for which the name Flagellimonas algarum sp. nov., is proposed with the type strain DF-77T (= KCTC 72791T = NBRC 114251T).
- MeSH
- DNA, Bacterial genetics chemistry MeSH
- Flavobacteriaceae * classification isolation & purification genetics MeSH
- Phospholipids analysis MeSH
- Phylogeny MeSH
- Genome, Bacterial MeSH
- Nucleic Acid Hybridization MeSH
- Fatty Acids analysis MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Bacterial Typing Techniques MeSH
- Vitamin K 2 analysis analogs & derivatives MeSH
- Base Composition MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Japan MeSH
In this study, lactic acid bacteria (LAB) isolation from fermented foods and molecular identification using magnetic bead technology were performed. And then exopolysaccharide (EPS) production possibility was tested in agar medium, and the positive ones were selected for the next step. The bacteria that could produce higher carbohydrate level were grown in MRS medium fortified with whey and pumpkin waste. In our study, 19 different LAB species were identified from fermented products collected from different places in Hatay (Türkiye) province. In molecular identification, universal primer pairs, p806R/p8FPL, and PEU7/DG74 were used for PCR amplification. After that, PCR products purified using paramagnetic bead technology were sequenced by the Sanger sequencing method. The dominant species, 23.8% of the isolates, were identified as Lactiplantibacillus plantarum. As a technological property of LAB, exopolysaccharide production capability of forty-two LAB isolate was tested in agar medium, and after eleven isolates were selected as positive. Two LAB (Latilactobacillus curvatus SHA2-3B and Loigolactobacillus coryniformis SHA6-3B) had higher EPS production capability when they were grown in MRS broth fortified with pumpkin waste and whey. The highest EPS content (1750 mg/L glucose equivalent) was determined in Loigolactobacillus coryniformis SHA6-3B grown in MRS broth fortified with 10% pumpkin waste. Besides the produced EPS samples were validated with FTIR and SEM methods.
- MeSH
- Polysaccharides, Bacterial * biosynthesis metabolism MeSH
- Cucurbita microbiology MeSH
- Fermentation MeSH
- Fermented Foods * microbiology MeSH
- Phylogeny MeSH
- Culture Media chemistry MeSH
- Lactobacillales * isolation & purification classification genetics metabolism MeSH
- Waste Products * analysis MeSH
- Food Microbiology * MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Whey MeSH
- Publication type
- Journal Article MeSH
A Mycobacterium smegmatis transcriptional regulator, MSMEG_5850, and its ortholog in M. tuberculosis, rv0775 were annotated as putative TetR Family Transcriptional Regulators. Our previous study revealed MSMEG_5850 is involved in global transcriptional regulation in M. smegmatis and the presence of gene product supported the survival of bacteria during nutritional starvation. Phylogenetic analysis showed that MSMEG_5850 diverged early in comparison to its counterparts in virulent strains. Therefore, the expression pattern of MSMEG_5850 and its counterpart, rv0775, was compared during various in-vitro growth and stress conditions. Expression of MSMEG_5850 was induced under different environmental stresses while no change in expression was observed under mid-exponential and stationary phases. No expression of rv0775 was observed under any stress condition tested, while the gene was expressed during the mid-exponential phase that declined in the stationary phase. The effect of MSMEG_5850 on the survival of M. smegmatis under stress conditions and growth pattern was studied using wild type, knockout, and supplemented strain. Deletion of MSMEG_5850 resulted in altered colony morphology, biofilm/pellicle formation, and growth pattern of M. smegmatis. The survival rate of wild-type MSMEG_5850 was higher in comparison to knockout under different environmental stresses. Overall, this study suggested the role of MSMEG_5850 in the growth and adaptation/survival of M. smegmatis under stress conditions.
- MeSH
- Bacterial Proteins * genetics metabolism MeSH
- Biofilms growth & development MeSH
- Phylogeny MeSH
- Stress, Physiological * MeSH
- Microbial Viability MeSH
- Mycobacterium smegmatis * genetics growth & development physiology metabolism MeSH
- Gene Expression Regulation, Bacterial MeSH
- Transcription Factors * genetics metabolism MeSH
- Publication type
- Journal Article MeSH
Halophilic bacteria are extremophiles that thrive in saline environment. Their ability to withstand such harsh conditions makes them an ideal choice for industrial applications such as lignocellulosic biomass degradation. In this study, a halophilic bacterium with the ability to produce extracellular cellulases and hemicellulases, designated as Nesterenkonia sp. CL21, was isolated from mangrove sediment in Tanjung Piai National Park, Malaysia. Thus far, studies on lignocellulolytic enzymes concerning bacterial species under this genus are limited. To gain a comprehensive understanding of its lignocellulose-degrading potential, the whole genome was sequenced using the Illumina NovaSeq 6000 platform. The genome of strain CL21 was assembled into 25 contigs with 3,744,449 bp and a 69.74% GC content and was predicted to contain 3,348 coding genes. Based on taxonomy analysis, strain CL21 shares 73.8 to 82.0% average nucleotide identity with its neighbouring species, below the 95% threshold, indicating its possible status as a distinct species in Nesterenkonia genus. Through in-depth genomic mining, a total of 81 carbohydrate-active enzymes were encoded. Among these, 24 encoded genes were identified to encompass diverse cellulases (GH3), xylanases (GH10, GH11, GH43, GH51, GH127 and CE4), mannanases (GH38 and GH106) and pectinases (PL1, PL9, and PL11). The production of lignocellulolytic enzymes was tested in the presence of several substrates. This study revealed that strain CL21 can produce a diverse array of enzymes which are active at different time points. By combining experimental data with genomic information, the ability of strain CL21 to produce lignocellulolytic enzymes has been elucidated, with potential applications in biorefinery industry.
- MeSH
- Bacterial Proteins genetics metabolism MeSH
- Cellulases genetics metabolism MeSH
- Phylogeny * MeSH
- Genome, Bacterial * MeSH
- Genomics * MeSH
- Geologic Sediments microbiology MeSH
- Glycoside Hydrolases * genetics metabolism MeSH
- Lignin * metabolism MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Whole Genome Sequencing MeSH
- Base Composition MeSH
- Publication type
- Journal Article MeSH
Allodiploid hybrid species, Aspergillus latus, belonging to section Nidulantes, is a hybrid of A. spinulosporus and an unknown species closely related to A. quadrilineatus and A. sublatus. This hybrid has often been misidentified as the species in section Nidulantes, such as A. nidulans, A. spinulosporus, A. sublatus, or other cryptic species. Aspergillus latus has not been reported in Japan as well as Asia so far. In this study, we screened 23 clinical strains identified as A. spinulosporus isolated in Japan from 2012 to 2023 and found seven A. latus strains. To characterize the A. latus strains, we conducted comprehensive phenotyping including morphological observation, whole genome sequences, and phylogenetic analysis based on calmodulin (CaM) gene. In addition, we conducted antifungal susceptibility testing for A. latus strains. As a result, the morphological characters of A. latus were more similar to those of A. spinulosporus compared to A. sublatus. However, the ascospore of A. latus differed from that of A. spinulosporus. Phylogenetic analysis revealed that different CaM alleles from the same isolate clustered separately with A. spinulosporus and A. sublatus, consistent with its hybrid origin. Furthermore, A. latus strains showed reduced susceptibility to caspofungin and amphotericin B compared to A. spinulosporus, while they were susceptible to azoles. Our results suggest that A. latus has been a causative pathogen of aspergillosis in Japan since 2013.
- MeSH
- Antifungal Agents pharmacology MeSH
- Aspergillus * genetics classification isolation & purification drug effects MeSH
- Aspergillosis * microbiology epidemiology MeSH
- Phylogeny MeSH
- Calmodulin genetics MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Whole Genome Sequencing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Japan MeSH
BACKGROUND: Human milk harbors diverse bacterial communities that contribute to infant health. Although pumping and storing milk is a common practice, the viable bacterial composition of pumped milk and the impact of storage practice on these bacteria remains under-explored. This metagenomic observational study aimed to characterize viable bacterial communities in freshly pumped human milk and its changes under different storage conditions. METHODS: In 2023, twelve lactating mothers from the CELSPAC: TNG cohort (Czech Republic) provided freshly pumped milk samples. These samples were stored under various conditions (refrigeration for 24 h, 48 h, or freezing for six weeks) and treated with propidium monoazide (PMA) to selectively identify viable cells. The DNA extracted from individual samples was subsequently analyzed using 16S rRNA amplicon sequencing on the Illumina platform. RESULTS: The genera Streptococcus, Staphylococcus, Diaphorobacter, Cutibacterium, and Corynebacterium were the most common viable bacteria in fresh human milk. The median sequencing depth and Shannon index of fresh human milk samples treated with PMA (+ PMA) were significantly lower than in untreated (-PMA) samples (p < 0.05 for all), which was true also for each time point. Also, significant changes in these parameters were observed between fresh human milk samples and their paired frozen samples (p < 0.05), while no differences were found between fresh human milk samples and those refrigerated for up to 48 h (p > 0.05). Of specific genera, only + PMA frozen human milk samples showed a significant decrease in the central log-ratio transformed relative abundances of the genera Diaphorobacter and Cutibacterium (p < 0.05) in comparison to + PMA fresh human milk samples. CONCLUSIONS: The study demonstrated that the bacterial profiles significantly differed between human milk samples treated with PMA, which represent only viable bacteria, and those untreated. While storage at 4 °C for up to 48 h did not significantly alter the overall diversity and composition of viable bacteria in human milk, freezing notably affected both the viability and relative abundances of some bacterial genera.
- MeSH
- Azides MeSH
- Bacteria * isolation & purification genetics classification MeSH
- Refrigeration MeSH
- Adult MeSH
- Humans MeSH
- Milk, Human * microbiology MeSH
- Microbiota * MeSH
- Propidium analogs & derivatives MeSH
- RNA, Ribosomal, 16S MeSH
- Food Storage * methods MeSH
- Freezing MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Observational Study MeSH
BACKGROUND: Understanding the temporal variability of the microbiome is critical for translating associations of the microbiome with health and disease into clinical practice. The aim of this study is to assess the extent of temporal variability of the human urinary microbiota. A pair of urine samples were collected from study participants at 3-40-month interval. DNA was extracted and the bacterial V4 hypervariable region of the 16S rRNA gene was sequenced on the Illumina MiSeq platform. The alpha diversity of paired samples was analyzed using Chao1 and Shannon indices and PERMANOVA was used to test the factors influencing beta diversity. RESULTS: A total of 63 participants (43 men and 20 women with a mean age of 63.0 and 57.1 years, respectively) were included in the final analysis. An average of 152 ± 128 bacterial operational taxonomic units (OTUs) were identified in each urine sample from the entire cohort. There was an average of 41 ± 32 overlapping OTUs in each sample pair, accounting for 66.3 ± 29.4% of the relative abundance. There was a clear correlation between the number of overlapping OTUs and the relative abundance covered. The difference in Chao1 index between paired samples was statistically significant; the difference in Shannon index was not. Beta diversity did not differ significantly within the paired samples. Neither age nor sex of the participants influenced the variation in community composition. With a longer interval between the collections, the relative abundance covered by the overlapping OTUs changed significantly but not the number of OTUs. CONCLUSION: Our findings demonstrated that, while the relative abundance of dominant bacteria varied, repeated collections generally shared more than 60% of the bacterial community. Furthermore, we observed little variation in the alpha and beta diversity of the microbial community in human urine. These results help to understand the dynamics of human urinary microbiota and enable interpretation of future studies.
- MeSH
- Bacteria * classification genetics isolation & purification MeSH
- Biodiversity MeSH
- Time Factors MeSH
- DNA, Bacterial genetics MeSH
- Middle Aged MeSH
- Humans MeSH
- Microbiota * genetics MeSH
- Urine * microbiology MeSH
- Prospective Studies MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Observational Study MeSH
