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Applied Microbiology and Biotechnology Dec 2024Marine bacteria living in association with marine sponges have proven to be a reliable source of biologically active secondary metabolites. However, no studies have yet...
Marine bacteria living in association with marine sponges have proven to be a reliable source of biologically active secondary metabolites. However, no studies have yet reported natural products from Microbacterium testaceum spp. We herein report the isolation of a M. testaceum strain from the sponge Tedania brasiliensis. Molecular networking analysis of bioactive pre-fractionated extracts from culture media of M. testaceum enabled the discovery of testacosides A-D. Analysis of spectroscopic data and chemical derivatizations allowed the identification of testacosides A-D as glycoglycerolipids bearing a 1-[α-glucopyranosyl-(1 → 3)-(α-mannopyranosyl)]-glycerol moiety connected to 12-methyltetradecanoic acid for testacoside A (1), 14-methylpentadecanoic acid for testacoside B (2), and 14-methylhexadecanoic acid for testacosides C (3) and D (4). The absolute configuration of the monosaccharide residues was determined by H-NMR analysis of the respective diastereomeric thiazolidine derivatives. This is the first report of natural products isolated from cultures of M. testaceum. KEY POINTS: • The first report of metabolites produced by Microbacterium testaceum. • 1-[α-Glucopyranosyl-(1 → 3)-(α-mannopyranosyl)]-glycerol lipids isolated and identified. • Microbacterium testaceum strain isolated from the sponge Tedania brasiliensis.
Topics: Animals; Glycerol; Porifera; Actinomycetales; Magnetic Resonance Spectroscopy; Biological Products; Microbacterium; Glycolipids
PubMed: 38217254
DOI: 10.1007/s00253-023-12870-0 -
Frontiers in Microbiology 2023The taxonomic relationships of 10 strains isolated from seaweeds collected from two beaches in Republic of Korea were studied by sequencing and analyses of 16S rRNA...
The taxonomic relationships of 10 strains isolated from seaweeds collected from two beaches in Republic of Korea were studied by sequencing and analyses of 16S rRNA genes and whole genomes. For the construction of a more reliable and robust 16S rRNA gene phylogeny, the authentic and nearly complete 16S rRNA gene sequences of all the type strains were selected through pairwise comparison of the sequences contained in several public databases including the List of Prokaryotic names with Standing in Nomenclature (LPSN). The clustering of the ten study strains into five distinct groups was apparent in this single gene-based phylogenetic tree. In addition, the 16S rRNA gene sequences of a few type strains were shown to be incorrectly listed in LPSN. An overall phylogenomic clustering of the genus was performed with a total of 113 genomes by core genome analysis. As a result, nine major (≥ three type strains) and eight minor (two type strains) clusters were defined mostly at gene support index of 92 and mean intra-cluster OrthoANIu of >80.00%. All of the study strains were assigned to a clade and distributed further into four subclusters in the core genome-based phylogenetic tree. phenotypic assays for physiological, biochemical, and chemotaxonomic characteristics were also carried out with the ten study strains and seven closely related type strains. Comparison of the overall genomic relatedness indices (OGRI) including OrthoANIu and digital DNA-DNA hybridization supported that the study strains constituted four new species of the genus . In addition, some type strains were reclassified as members of preexisting species. Moreover, some of them were embedded in a new genus of the family based on their distinct separation in the core genome-based phylogenetic tree and amino acid identity matrices. Based on the results here, four new species, namely, sp. nov., sp. nov., sp. nov., and sp. nov., are described, along with the proposal of gen. nov. containing five reclassified species from the " clade", with gen. nov., comb. nov. as the type species.
PubMed: 38164402
DOI: 10.3389/fmicb.2023.1299950 -
The Science of the Total Environment Feb 2024A naturally occurring multispecies bacterial community composed of Bacillus cereus and two novel bacteria (Microbacterium forte sp. nov. and Stenotrophomonas goyi sp....
A naturally occurring multispecies bacterial community composed of Bacillus cereus and two novel bacteria (Microbacterium forte sp. nov. and Stenotrophomonas goyi sp. nov.) has been identified from a contaminated culture of the microalga Chlamydomonas reinhardtii. When incubated in mannitol- and yeast extract-containing medium, this bacterial community can promote and sustain algal hydrogen production up to 313 mL H·L for 17 days and 163.5 mL H·L for 25 days in high-cell (76.7 μg·mL of initial chlorophyll) and low-cell density (10 μg·mL of initial chlorophyll) algal cultures, respectively. In low-cell density algal cultures, hydrogen production was compatible with algal growth (reaching up to 60 μg·mL of chlorophyll). Among the bacterial community, M. forte sp. nov. was the sole responsible for the improvement in hydrogen production. However, algal growth was not observed in the Chlamydomonas-M. forte sp. nov. consortium during hydrogen-producing conditions (hypoxia), suggesting that the presence of B. cereus and S. goyi sp. nov. could be crucial to support the algal growth during hypoxia. Still, under non‑hydrogen producing conditions (aerobiosis) the Chlamydomonas-M. forte sp. nov. consortium allowed algal growth (up to 40 μg·mL of chlorophyll) and long-term algal viability (>45 days). The genome sequence and growth tests of M. forte sp. nov. have revealed that this bacterium is auxotroph for biotin and thiamine and unable to use sulfate as sulfur source; it requires S-reduced forms such as cysteine and methionine. Cocultures of Chlamydomonas reinhardtii and M. forte sp. nov. established a mutualistic association: the alga complemented the nutrient deficiencies of the bacterium, while the bacterium released ammonium (0.19 mM·day) and acetic acid (0.15 mM·day) for the alga. This work offers a promising avenue for photohydrogen production concomitant with algal biomass generation using nutrients not suitable for mixotrophic algal growth.
Topics: Chlamydomonas reinhardtii; Microbacterium; Chlorophyll; Chlamydomonas; Acetic Acid; Bacteria; Hypoxia; Hydrogen
PubMed: 38159768
DOI: 10.1016/j.scitotenv.2023.169559 -
Food Chemistry: X Dec 2023Pyrroloquinoline quinone disodium (PQQ·Na) has been considered a human food supplement for human health promotion with its antioxidant properties. To determine whether...
Pyrroloquinoline quinone disodium (PQQ·Na) has been considered a human food supplement for human health promotion with its antioxidant properties. To determine whether PQQ·Na had similar functions to improve the antioxidant ability of layers and eggs, 180 laying hens were fed with 0 or 0.4 mg/kg PQQ·Na diets. Supplementation with PQQ·Na increased the albumen height, Haugh unit of the eggs. PQQ·Na also led to a higher glutathione peroxidase (GSH-Px) concentration in plasma and a lower malondialdehyde (MDA) content in the liver and egg yolk. Similarly, liver gene and protein expression of nuclear factor erythroid 2-related 2 (Nrf2) and heme oxygenase 1 (HO-1) were up-regulated by PQQ·Na Moreover, PQQ·Na increased the abundance of , and in gut. Overall, these results suggested PQQ·Na increased the antioxidant ability of layers and eggs which might be in connection with the activation of the Nrf2/HO-1 pathway and optimized gut microflora.
PubMed: 38144785
DOI: 10.1016/j.fochx.2023.101021 -
Microbiology Resource Announcements Feb 2024BabyYoda and Lynlen are two cluster EB phages that were discovered at Thiel College using NRRL B-24224. Both BabyYoda and Lynlen are predicted to be lytic, with...
BabyYoda and Lynlen are two cluster EB phages that were discovered at Thiel College using NRRL B-24224. Both BabyYoda and Lynlen are predicted to be lytic, with siphovirus morphologies, with genome sizes of 41,557 and 41,448 base pairs, respectively.
PubMed: 38132671
DOI: 10.1128/mra.01006-23 -
Frontiers in Microbiology 2023Chinese plum ( Lindl.) is a nutritionally and economically important stone fruit widely grown around the world. Anthracnose, caused by spp., is one of the primary...
Chinese plum ( Lindl.) is a nutritionally and economically important stone fruit widely grown around the world. Anthracnose, caused by spp., is one of the primary biotic stress factors limiting plum production. Medicinal plants may harbor rhizospheric or endophytic microorganisms that produce bioactive metabolites that can be used as anthracnose biocontrol agents. Here, 27 bacterial isolates from the medicinal plant with diverse antagonistic activities against were screened. Based on morphological, physiological, biochemical, and molecular characterization, 25 of these isolates belong to different species of genus , one to , and one more to . Eight representative strains showed high biocontrol efficacy against plum anthracnose in a pot experiment. In addition, several isolates showed a broad spectrum of inhibitory activity against a variety of fungal phytopathogens. Analysis of the volatile organic compound profile of these eight representative strains revealed a total of 47 compounds, most of which were ketones, while the others included alkanes, alkenes, alcohols, pyrazines, and phenols. Overall, this study confirmed the potential value of eight bacterial isolates for development as anthracnose biocontrol agents.
PubMed: 38130944
DOI: 10.3389/fmicb.2023.1296755 -
PloS One 2023The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing... (Meta-Analysis)
Meta-Analysis
The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing oral bacteria reduce inorganic dietary NO3- to nitrite (NO2-) via the NO3--NO2--NO pathway. Studies of oral NO3--reducing bacteria have typically sampled from either the tongue surface or saliva. The aim of this study was to assess whether other areas in the mouth could contain a physiologically relevant abundance of NO3- reducing bacteria, which may be important for sampling in clinical studies. The bacterial composition of seven oral sample types from 300 individuals were compared using a meta-analysis of the Human Microbiome Project data. This analysis revealed significant differences in the proportions of 20 well-established oral bacteria and highly abundant NO3--reducing bacteria across each oral site. The genera included Actinomyces, Brevibacillus, Campylobacter, Capnocytophaga, Corynebacterium, Eikenella, Fusobacterium, Granulicatella, Haemophilus, Leptotrichia, Microbacterium, Neisseria, Porphyromonas, Prevotella, Propionibacterium, Rothia, Selenomonas, Staphylococcus, Streptococcus and Veillonella. The highest proportion of NO3--reducing bacteria was observed in saliva, where eight of the bacterial genera were found in higher proportion than on the tongue dorsum, whilst the lowest proportions were found in the hard oral surfaces. Saliva also demonstrated higher intra-individual variability and bacterial diversity. This study provides new information on where samples should be taken in the oral cavity to assess the abundance of NO3--reducing bacteria. Taking saliva samples may benefit physiological studies, as saliva contained the highest abundance of NO3- reducing bacteria and is less invasive than other sampling methods. These results inform future studies coupling oral NO3--reducing bacteria research with physiological outcomes affecting human health.
Topics: Humans; Nitrates; Nitrogen Dioxide; Mouth; Bacteria; Saliva; Microbiota; Streptococcus
PubMed: 38127919
DOI: 10.1371/journal.pone.0295058 -
Frontiers in Plant Science 2023In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to...
In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to eggs. This results in progeny seed. However, environmental fungal pathogens invade developing seeds through the style. We hypothesized that prior to environmental exposure, style tissue already possesses bacteria that can protect styles and seed from such pathogens. We further hypothesized that farmers have been inadvertently selecting immature styles over many generations to have such bacteria. We tested these hypotheses in maize, a wind-pollinated crop, which has unusually long styles (silks) that are invaded by the economically-important fungal pathogen (). Here, unpollinated silk-associated bacteria were cultured from a wild teosinte ancestor of maize and diverse maize landraces selected by indigenous farmers across the Americas, grown in a common Canadian field for one season. The bacteria were taxonomically classified using 16S rRNA sequencing. In total, 201 bacteria were cultured, spanning 29 genera, 63 species, and 62 unique OTUs, dominated by and . These bacteria were tested for their ability to suppress which identified 10 strains belonging to 6 species: , and Two anti- strains were sprayed onto silks before/after inoculation, resulting in ≤90% reductions in disease (Gibberella ear rot) and 70-100% reductions in associated mycotoxins (deoxynivalenol and zearalenone) in progeny seeds. These strains also protected progeny seeds post-harvest. Confocal fluorescent imaging showed that one silk bacterium ( AS112) colonized susceptible entry points of on living silks including stigmatic trichomes, wounds, and epidermal surfaces where they formed thick biofilms. Post-infection, AS112 was associated with masses of dead hyphae. These results suggest that the maize style (silk) is endowed with potent bacteria from the mother plant to protect itself and progeny from . The evidence suggests this trait may have been selected by specific indigenous peoples, though this interpretation requires further study.
PubMed: 38111882
DOI: 10.3389/fpls.2023.1292109 -
Frontiers in Cellular and Infection... 2023There is a clinical challenge in diagnosing tuberculous pleurisy accurately and promptly, highlighting the urgent need for a rapid and sensitive diagnostic method. This...
INTRODUCTION
There is a clinical challenge in diagnosing tuberculous pleurisy accurately and promptly, highlighting the urgent need for a rapid and sensitive diagnostic method. This study aimed to evaluate the diagnostic accuracy of metagenomic next-generation sequencing (mNGS) and GeneXpert (MTB) for identifying tuberculous pleurisy and analyzing the microbial profiles of both tuberculous and non-tuberculous pleural effusions.
METHODS
The study enrolled 31 patients with suspected tuberculous pleurisy, of which 15 were confirmed to have tuberculous pleurisy and subsequently allocated to the tuberculous pleurisy group (TP group), while the remaining 16 individuals were assigned to the non-tuberculous pleurisy group (NTP group). mNGS and GeneXpert MTB were performed on pleural effusion samples, and the diagnostic accuracy of both tests was compared. We employed established formulas to compute crucial indicators, including sensitivity, specificity, missed diagnosis rate, misdiagnosed rate, positive predictive value (PPV), and negative predictive value (NPV).
RESULTS
The results showed that both tests had high specificity (100%) and positive predictive value (100%) for detecting tuberculous pleurisy, along with comparable sensitivity (46.67% for mNGS and 40.0% for GeneXpert MTB). Further analysis of the combined efficacy of mNGS and GeneXpert MTB showed that the combined test had a sensitivity of 66.67% and a specificity of 100%. mNGS analysis revealed that MTB was detected in 7 out of 15 patients with tuberculous pleural effusions, while non-tuberculous pleural effusions were associated with a diverse range of microbial genera and species. The most frequently detected genera at the microbial genus level in the NTP group were spp. (6/16), spp. (5/16), and spp. (5/16).
DISCUSSION
These findings suggest that mNGS and GeneXpert MTB are useful diagnostic tools for identifying patients with tuberculous pleurisy, and mNGS can provide valuable insights into the microbial profiles of both tuberculous and non-tuberculous pleural effusions.
Topics: Humans; Mycobacterium tuberculosis; Tuberculosis, Pleural; High-Throughput Nucleotide Sequencing; Sensitivity and Specificity; Pleural Effusion
PubMed: 38089819
DOI: 10.3389/fcimb.2023.1243441 -
Frontiers in Medicine 2023Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7...
INTRODUCTION
Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7 patients at our peritoneal dialysis center.
METHODS
We retrospectively collected clinical characteristics and antibiotic management of all 7 episodes of PDRP caused by . in 7 patients from at our center over 4 years, and reviewed the documented . PDRP in the literature.
RESULTS
Empiric antibiotic therapy was initiated as soon as possible, and consisted of intraperitoneal (IP) gentamicin in combination with vancomycin. After up to 5 days, gentamicin was changed to meropenem if the treatment was not effective. The intended course of antibiotic treatment was 21-day. Totally, 6 episodes were cured (85.7%), which was higher than reported.
CONCLUSION
The 21-day antibiotic therapy program by combining vancomycin and meropenem may benefit the management of . PDRP.
PubMed: 38076234
DOI: 10.3389/fmed.2023.1297296