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Applied Microbiology and Biotechnology Jan 2024As the problem of antimicrobial resistance is constantly increasing, there is a renewed interest in antimicrobial products derived from natural sources, particularly...
As the problem of antimicrobial resistance is constantly increasing, there is a renewed interest in antimicrobial products derived from natural sources, particularly obtained from innovative and eco-friendly materials. Insect lipids, due to their fatty acid composition, can be classified as natural antimicrobial compounds. In order to assess the antibacterial efficacy of Hermetia illucens lipids, we extracted this component from the larval stage, fed on different substrates and we characterized it. Moreover, we analyzed the fatty acid composition of the feeding substrate, to determine if and how it could affect the antimicrobial activity of the lipid component. The antimicrobial activity was evaluated against Gram-positive Micrococcus flavus and Gram-negative bacteria Escherichia coli. Analyzing the fatty acid profiles of larval lipids that showed activity against the two bacterial strains, we detected significant differences for C4:0, C10:0, C16:1, C18:3 n3 (ALA), and C20:1. The strongest antimicrobial activity was verified against Micrococcus flavus by lipids extracted from larvae reared on strawberry, tangerine, and fresh manure substrates, with growth inhibition zones ranged from 1.38 to 1.51 mm, while only the rearing on manure showed the effect against Escherichia coli. Notably, the fatty acid profile of H. illucens seems to not be really influenced by the substrate fatty acid profile, except for C18:0 and C18:2 CIS n6 (LA). This implies that other factors, such as the rearing conditions, larval development stages, and other nutrients such as carbohydrates, affect the amount of fatty acids in insects. KEY POINTS: • Feeding substrates influence larval lipids and fatty acids (FA) • Generally, there is no direct correlation between substrate FAs and the same larvae FAs • Specific FAs influence more the antimicrobial effect of BSF lipids.
Topics: Animals; Manure; Larva; Escherichia coli; Fatty Acids; Micrococcus luteus; Diptera; Micrococcus
PubMed: 38261012
DOI: 10.1007/s00253-024-13005-9 -
Environmental Microbiome Mar 2024Bacteria and fungi are dynamically interconnected, leading to beneficial or antagonistic relationships with plants. Within this interkingdom interaction, the microbial...
BACKGROUND
Bacteria and fungi are dynamically interconnected, leading to beneficial or antagonistic relationships with plants. Within this interkingdom interaction, the microbial community directly associated with the pathogen make up the pathobiome. While the overall soil bacterial community associated with Fusarium wilt diseases has been widely examined, the specific bacterial populations that directly interact with the Fusarium wilt pathogens are yet to be discovered. In this study, we define the bacterial community associated with the hyphae of Fusarium oxysporum f. sp. niveum race 2 (FON2). Using the 16S rRNA gene metabarcoding, we describe the hyphosphere pathobiome of three isolates of FON2.
RESULTS
Our results show a core microbiome that is shared among the three tested hyphospheres. The core hyphosphere community was made up of 15 OTUs (Operational Taxonomic Units) that were associated with all three FON2 isolates. This core consisted of bacterial members of the families, Oxalobacteraceae, Propionibacteriaceae, Burkholderiaceae, Micrococcaceae, Bacillaceae, Comamonadaceae, Pseudomonadaceae and unclassified bacteria. The hyphosphere of FON2 was dominated by order Burkholderiales. While all three isolate hyphospheres were dominated by these taxa, the specific OTU differed. We also note that while the dominant OTU of one hyphosphere might not be the largest OTU for other hyphospheres, they were still present across all the three isolate hyphospheres. Additionally, in the correlation and co-occurrence analysis the most abundant OTU was negatively correlated with most of the other OTU populations within the hyphosphere.
CONCLUSIONS
The study indicates a core microbiota associated with FON2. These results provide insights into the microbe-microbe dynamic of the pathogen's success and its ability to recruit a core pathobiome. Our research promotes the concept of pathogens not being lone invaders but recruits from the established host microbiome to form a pathobiome.
PubMed: 38461269
DOI: 10.1186/s40793-024-00558-5 -
PeerJ 2023The gut microbiota is a complex ecosystem that interacts with many other factors to affect the health and disease states of the host. The common kestrel () is protected...
The gut microbiota is a complex ecosystem that interacts with many other factors to affect the health and disease states of the host. The common kestrel () is protected at the national level in China. However, the available sequencing data of the gut microbiota from the feces of wild common kestrels, especially for being rescued individuals by professional organization, remains limited. In the present study, we characterized the fecal bacterial communities of healthy and injured common kestrels, and compared the structure of their fecal microbiota by analyzing the V3-V4 region of the 16S rRNA gene using high-throughput sequencing technology with the Illumina MiSeq platform. We found that Firmicutes, Proteobacteria and Actinobacteria were the most predominant phyla in common kestrels. Further, the beta diversity analysis showed that changes in gut microbes were associated with injuries to the common kestrel. The Bacteroides/Firmicutes ratio was significantly lower in the injured group. At the genus level, showed significant difference in the two groups. The aim of our current study was to characterize the basic bacterial composition and community structure in the feces of healthy common kestrels, and then compare the differences in the fecal microbiota between healthy and injured individuals. Patescibacteria, Spirochaetes, and may be studied as potential biomarkers for certain diseases in raptors. The results could provide the basic data for additional research on the fecal microbiota of common kestrels and contribute to the rescue of wild raptors in the future.
Topics: Humans; Animals; Raptors; Beijing; RNA, Ribosomal, 16S; Falconiformes; Microbiota; Micrococcaceae; Firmicutes; Feces; Regulatory-Associated Protein of mTOR
PubMed: 37637157
DOI: 10.7717/peerj.15789 -
Journal of Hazardous Materials Sep 2023Deep Geological Repository (DGR) is the preferred option for the final disposal of high-level radioactive waste. Microorganisms could affect the safety of the DGR by...
Impact of compacted bentonite microbial community on the clay mineralogy and copper canister corrosion: a multidisciplinary approach in view of a safe Deep Geological Repository of nuclear wastes.
Deep Geological Repository (DGR) is the preferred option for the final disposal of high-level radioactive waste. Microorganisms could affect the safety of the DGR by altering the mineralogical properties of the compacted bentonite or inducing the corrosion of the metal canisters. In this work, the impact of physicochemical parameters (bentonite dry density, heat shock, electron donors/acceptors) on the microbial activity, stability of compacted bentonite and corrosion of copper (Cu) discs was investigated after one-year anoxic incubation at 30 ºC. No-illitization in the bentonite was detected confirming its structural stability over 1 year under the experimental conditions. The microbial diversity analysis based on 16 S rRNA gene Next Generation Sequencing showed slight changes between the treatments with an increase of aerobic bacteria belonging to Micrococcaceae and Nocardioides in heat-shock tyndallized bentonites. The survival of sulfate-reducing bacteria (the main source of Cu anoxic corrosion) was demonstrated by the most probable number method. The detection of CuS precipitates on the surface of Cu metal in the bentonite/Cu metal samples amended with acetate/lactate and sulfate, indicated an early stage of Cu corrosion. Overall, the outputs of this study help to better understand the predominant biogeochemical processes at the bentonite/Cu canister interface upon DGR closure.
Topics: Bentonite; Radioactive Waste; Copper; Clay; Corrosion; Microbiota; Sulfates
PubMed: 37390682
DOI: 10.1016/j.jhazmat.2023.131940 -
Annals of Laboratory Medicine Sep 2023
Topics: Humans; Micrococcaceae; Bacteremia; Catheters; Republic of Korea
PubMed: 37080756
DOI: 10.3343/alm.2023.43.5.520 -
Animals : An Open Access Journal From... May 2024This study aimed to investigate the effects of the dietary fiber pectin on the gut microbiota and health of parturient sows. A total of 30 parity 5-7, multiparous...
This study aimed to investigate the effects of the dietary fiber pectin on the gut microbiota and health of parturient sows. A total of 30 parity 5-7, multiparous gestation sows (Large White × Landrace) were randomly assigned to two treatment groups after mating: Con (control, basic diet) and Pec (pectin, 3%). The sows received the two diets during gestation, and all sows were fed the same standard basic diet during lactation. The results of β-diversity showed that the composition of the gut microbiota was different in the Con and Pec groups. Compared with the sows in the Con group, the Pec sows showed a higher abundance of the gut bacteria and and a lower abundance of harmful bacteria (, , , ). On the other hand, the SCFA plasma concentration was increased in the Pec group, while pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) concentrations were decreased. In conclusion, the soluble dietary fiber pectin could improve the reproductive performance and health of sows by increasing the abundance of some commensal bacteria enhancing the metabolite SCFA levels and reducing the pro-inflammatory cytokine plasma levels.
PubMed: 38891606
DOI: 10.3390/ani14111559 -
Revista Espanola de Quimioterapia :... Feb 2024
Topics: Humans; Teicoplanin; Micrococcaceae; Endocarditis; Anti-Bacterial Agents; Endocarditis, Bacterial
PubMed: 38131630
DOI: 10.37201/req/051.2023 -
Marine Drugs Feb 2024Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control...
Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control the degree of sulfation, are being more extensively researched. In this work, a novel sulfatase (SulA1) encoded by the gene was characterized. The -gene is located upstream of a chondroitin lyase encoding gene in the genome of the marine Arthrobacter strain (MAT3885). The sulfatase was produced in . Based on the primary sequence, the enzyme is classified under sulfatase family 1 and the two catalytic residues typical of the sulfatase 1 family-Cys57 (post-translationally modified to formyl glycine for function) and His190-were conserved. The enzyme showed increased activity, but not improved stability, in the presence of Ca, and conserved residues for Ca binding were identified (Asp17, Asp18, Asp277, and Asn278) in a structural model of the enzyme. The temperature and pH activity profiles (screened using -nitrocatechol sulfate) were narrow, with an activity optimum at 40-50 °C and a pH optimum at pH 5.5. The was significantly higher (67 °C) than the activity optimum. Desulfation activity was not detected on polymeric substrates, but was found on GalNAc4S, which is a sulfated monomer in the repeated disaccharide unit (GlcA-GalNAc4S) of, e.g., chondroitin sulfate A. The position of the sulA1 gene upstream of a chondroitin lyase gene and combined with the activity on GalNAc4S suggests that there is an involvement of the enzyme in the chondroitin-degrading cascade reaction, which specifically removes sulfate from monomeric GalNAc4S from chondroitin sulfate degradation products.
Topics: Sulfates; Acetylgalactosamine; Arthrobacter; Sulfatases; Escherichia coli; Galactosamine; Chondroitin Lyases; Cloning, Molecular
PubMed: 38535445
DOI: 10.3390/md22030104 -
Plant Physiology and Biochemistry : PPB May 2024Plant microbial biostimulants application has become a promising and eco-friendly agricultural strategy to improve crop yields, reducing chemical inputs for more...
Plant microbial biostimulants application has become a promising and eco-friendly agricultural strategy to improve crop yields, reducing chemical inputs for more sustainable cropping systems. The soil dwelling bacterium Kocuria rhizophila was previously characterized as Plant Growth Promoting Bacteria (PGPB) for its multiple PGP traits, such as indole-3-acetic acid production, phosphate solubilization capability and salt and drought stress tolerance. Here, we evaluated by a multi-omics approach, the PGP activity of K. rhizophila on tomato, revealing the molecular pathways by which it promotes plant growth. Transcriptomic analysis showed several up-regulated genes mainly related to amino acid metabolism, cell wall organization, lipid and secondary metabolism, together with a modulation in the DNA methylation profile, after PGPB inoculation. In agreement, proteins involved in photosynthesis, cell division, and plant growth were highly accumulated by K. rhizophila. Furthermore, "amino acid and peptides", "monosaccharides", and "TCA" classes of metabolites resulted the most affected by PGPB treatment, as well as dopamine, a catecholamine neurotransmitter mediating plant growth through S-adenosylmethionine decarboxylase (SAMDC), a gene enhancing the vegetative growth, up-regulated in tomato by K. rhizophila treatment. Interestingly, eight gene modules well correlated with differentially accumulated proteins (DAPs) and metabolites (DAMs), among which two modules showed the highest correlation with nine proteins, including a nucleoside diphosphate kinase, and cytosolic ascorbate peroxidase, as well as with several amino acids and metabolites involved in TCA cycle. Overall, our findings highlighted that sugars and amino acids, energy regulators, involved in tomato plant growth, were strongly modulated by the K. rhizophila-plant interaction.
Topics: Solanum lycopersicum; Micrococcaceae; Soil Microbiology; Gene Expression Regulation, Plant
PubMed: 38615442
DOI: 10.1016/j.plaphy.2024.108609 -
Microbial Cell Factories May 2024Quantum Dots (QDs) are fluorescent nanoparticles with exceptional optical and optoelectronic properties, finding widespread utility in diverse industrial applications....
BACKGROUND
Quantum Dots (QDs) are fluorescent nanoparticles with exceptional optical and optoelectronic properties, finding widespread utility in diverse industrial applications. Presently, chemically synthesized QDs are employed in solar cells, bioimaging, and various technological domains. However, many applications demand QDs with prolonged lifespans under conditions of high-energy radiation. Over the past decade, microbial biosynthesis of nanomaterials has emerged as a sustainable and cost-effective process. In this context, the utilization of extremophile microorganisms for synthesizing QDs with unique properties has recently been reported.
RESULTS
In this study, UV-resistant bacteria were isolated from one of the most extreme environments in Antarctica, Union Glacier at the Ellsworth Mountains. Bacterial isolates, identified through 16 S sequencing, belong to the genera Rhodococcus, Pseudarthrobacter, and Arthrobacter. Notably, Rhodococcus sp. (EXRC-4 A-4), Pseudarthrobacter sp. (RC-2-3), and Arthrobacter sp. (EH-1B-1) tolerate UV-C radiation doses ≥ 120 J/m². Isolated UV-resistant bacteria biosynthesized CdS QDs with fluorescence intensities 4 to 8 times higher than those biosynthesized by E. coli, a mesophilic organism tolerating low doses of UV radiation. Transmission electron microscopy (TEM) analysis determined QD sizes ranging from 6 to 23 nm, and Fourier-transform infrared (FTIR) analysis demonstrated the presence of biomolecules. QDs produced by UV-resistant Antarctic bacteria exhibit high photostability after exposure to UV-B radiation, particularly in comparison to those biosynthesized by E. coli. Interestingly, red fluorescence-emitting QDs biosynthesized by Rhodococcus sp. (EXRC-4 A-4) and Arthrobacter sp. (EH-1B-1) increased their fluorescence emission after irradiation. Analysis of methylene blue degradation after exposure to irradiated QDs biosynthesized by UV-resistant bacteria, indicates that the QDs transfer their electrons to O for the formation of reactive oxygen species (ROS) at different levels.
CONCLUSIONS
UV-resistant Antarctic bacteria represent a novel alternative for the sustainable generation of nanostructures with increased radiation tolerance-two characteristics favoring their potential application in technologies requiring continuous exposure to high-energy radiation.
Topics: Quantum Dots; Antarctic Regions; Ultraviolet Rays; Cadmium Compounds; Rhodococcus; Arthrobacter; Sulfides
PubMed: 38760827
DOI: 10.1186/s12934-024-02417-x