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Communications Biology Nov 2021The gut microbiome produces vitamins, nutrients, and neurotransmitters, and helps to modulate the host immune system-and also plays a major role in the metabolism of...
The gut microbiome produces vitamins, nutrients, and neurotransmitters, and helps to modulate the host immune system-and also plays a major role in the metabolism of many exogenous compounds, including drugs and chemical toxicants. However, the extent to which specific microbial species or communities modulate hazard upon exposure to chemicals remains largely opaque. Focusing on the effects of collateral dietary exposure to the widely used herbicide atrazine, we applied integrated omics and phenotypic screening to assess the role of the gut microbiome in modulating host resilience in Drosophila melanogaster. Transcriptional and metabolic responses to these compounds are sex-specific and depend strongly on the presence of the commensal microbiome. Sequencing the genomes of all abundant microbes in the fly gut revealed an enzymatic pathway responsible for atrazine detoxification unique to Acetobacter tropicalis. We find that Acetobacter tropicalis alone, in gnotobiotic animals, is sufficient to rescue increased atrazine toxicity to wild-type, conventionally reared levels. This work points toward the derivation of biotic strategies to improve host resilience to environmental chemical exposures, and illustrates the power of integrative omics to identify pathways responsible for adverse health outcomes.
Topics: Acetobacter; Animals; Atrazine; Drosophila melanogaster; Female; Gastrointestinal Microbiome; Host Microbial Interactions; Inactivation, Metabolic; Insecticides; Male
PubMed: 34819611
DOI: 10.1038/s42003-021-02847-y -
Microbiology Spectrum Oct 2021Insecticide resistance among mosquito species is now a pervasive phenomenon that threatens to jeopardize global malaria vector control efforts. Evidence of links between...
Insecticide resistance among mosquito species is now a pervasive phenomenon that threatens to jeopardize global malaria vector control efforts. Evidence of links between the mosquito microbiota and insecticide resistance is emerging, with significant enrichment of insecticide degrading bacteria and enzymes in resistant populations. Using 16S rRNA amplicon sequencing, we characterized and compared the microbiota of Anopheles coluzzii in relation to their deltamethrin resistance and exposure profiles. Comparisons between 2- and 3-day-old deltamethrin-resistant and -susceptible mosquitoes demonstrated significant differences in microbiota diversity. , , and genera, each of which comprised insecticide-degrading species, were significantly enriched in resistant mosquitoes. Susceptible mosquitoes had a significant reduction in alpha diversity compared to resistant individuals, with and dominating microbial profiles. There was no significant difference in deltamethrin-exposed and -unexposed 5- to 6-day-old individuals, suggesting that insecticide exposure had minimal impact on microbial composition. and were also dominant in 5- to 6-day-old mosquitoes, which had reduced microbial diversity compared to 2- to 3-day-old mosquitoes. Our findings revealed significant alterations of Anopheles coluzzii microbiota associated with deltamethrin resistance, highlighting the potential for identification of novel microbial markers for insecticide resistance surveillance. qPCR detection of and was consistent with 16S rRNA sequencing, suggesting that population-level field screening of bacterial microbiota may be feasibly integrated into wider resistance monitoring, if reliable and reproducible markers associated with phenotype can be identified. Control of insecticide-resistant vector populations remains a significant challenge to global malaria control and while substantial progress has been made elucidating key target site mutations, overexpressed detoxification enzymes and alternate gene families, the contribution of the mosquito microbiota to phenotypic insecticide resistance has been largely overlooked. We focused on determining the effects of deltamethrin resistance intensity on Anopheles coluzzii microbiota and identifying any microbial taxa associated with phenotype. We demonstrated a significant reduction in microbial diversity between deltamethrin-resistant and -susceptible mosquitoes. Insecticide degrading bacterial species belonging to , , and genera were significantly enriched in resistant mosquitoes, while and dominated microbial profiles of susceptible individuals. Our results revealed significant alterations of Anopheles coluzzii microbiota associated with deltamethrin resistance, highlighting the potential for identification of novel microbial markers for surveillance and opportunities for designing innovative control techniques to prevent the further evolution and spread of insecticide resistance.
Topics: Acetobacteraceae; Animals; Anopheles; Cote d'Ivoire; Insecticide Resistance; Insecticides; Malaria; Microbiota; Mosquito Vectors; Nitriles; Pyrethrins; RNA, Ribosomal, 16S; Serratia
PubMed: 34668745
DOI: 10.1128/Spectrum.00157-21 -
PLoS Biology Oct 2019Imaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many...
Imaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many species adopt similar morphologies. While prior studies have relied on techniques involving spectral labeling, we have developed an expansion microscopy method (μExM) in which bacterial cells are physically expanded prior to imaging. We find that expansion patterns depend on the structural and mechanical properties of the cell wall, which vary across species and conditions. We use this phenomenon as a quantitative and sensitive phenotypic imaging contrast orthogonal to spectral separation to resolve bacterial cells of different species or in distinct physiological states. Focusing on host-microbe interactions that are difficult to quantify through fluorescence alone, we demonstrate the ability of μExM to distinguish species through an in vitro defined community of human gut commensals and in vivo imaging of a model gut microbiota, and to sensitively detect cell-envelope damage caused by antibiotics or previously unrecognized cell-to-cell phenotypic heterogeneity among pathogenic bacteria as they infect macrophages.
Topics: Acetobacter; Acidaminococcus; Animals; Anti-Bacterial Agents; Cell Wall; Drosophila melanogaster; Escherichia coli; Gastrointestinal Microbiome; Humans; Hydrolysis; Lactobacillus plantarum; Mice; Microscopy; Muramidase; Platyhelminths; RAW 264.7 Cells; Stress, Mechanical; Symbiosis; Vancomycin
PubMed: 31622337
DOI: 10.1371/journal.pbio.3000268 -
Bioengineered Apr 2022Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste...
Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of value-added products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FE-SEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa.
Topics: Acetobacteraceae; Agriculture; Cellulose; Culture Media; Fermentation; Saccharum
PubMed: 35416127
DOI: 10.1080/21655979.2022.2062970 -
Microbial Biotechnology Sep 2019The recent interest in plant pigment betalains as bioactive compounds and chemopreventive agents has led to the search for a reliable and scalable process to obtain...
The recent interest in plant pigment betalains as bioactive compounds and chemopreventive agents has led to the search for a reliable and scalable process to obtain them. The cloning of the novel and efficient enzyme 4,5-DOPA-extradiol dioxygenase from Gluconacetobacter diazotrophicus in an expression vector, and the subsequent heterologous expression in Escherichia coli cultures has led to the start-up of a biotechnological production system of individual pigments. The aim of this study was to search for the optimal conditions for the production of betalamic acid in microbial factories and the scaled-up obtention of the derived pigments. Four different betaxanthins and two betacyanins were obtained after the addition of non-transformable amines and amino acids and their condensation with the betalamic acid produced by the dioxygenase. The scaled-up obtention and purification of betalains improved the yields of the previous methodologies reaching quantities by up to 150 mg of pure compounds.
Topics: Betalains; Biotechnology; Biotransformation; Cloning, Molecular; Coloring Agents; Dioxygenases; Escherichia coli; Gene Expression; Gluconacetobacter; Metabolic Engineering; Pyridines
PubMed: 31270958
DOI: 10.1111/1751-7915.13452 -
BMC Structural Biology Nov 2014Bacterial pyruvate decarboxylases (PDC) are rare. Their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued...
BACKGROUND
Bacterial pyruvate decarboxylases (PDC) are rare. Their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued and growing interest. PDCs from Zymomonas mobilis (ZmPDC), Zymobacter palmae (ZpPDC) and Sarcina ventriculi (SvPDC) have been characterized and ZmPDC has been produced successfully in a range of heterologous hosts. PDCs from the Acetobacteraceae and their role in metabolism have not been characterized to the same extent. Examples include Gluconobacter oxydans (GoPDC), G. diazotrophicus (GdPDC) and Acetobacter pasteutrianus (ApPDC). All of these organisms are of commercial importance.
RESULTS
This study reports the kinetic characterization and the crystal structure of a PDC from Gluconacetobacter diazotrophicus (GdPDC). Enzyme kinetic analysis indicates a high affinity for pyruvate (K M 0.06 mM at pH 5), high catalytic efficiencies (1.3 • 10(6) M(-1) • s(-1) at pH 5), pHopt of 5.5 and Topt at 45°C. The enzyme is not thermostable (T½ of 18 minutes at 60°C) and the calculated number of bonds between monomers and dimers do not give clear indications for the relatively lower thermostability compared to other PDCs. The structure is highly similar to those described for Z. mobilis (ZmPDC) and A. pasteurianus PDC (ApPDC) with a rmsd value of 0.57 Å for Cα when comparing GdPDC to that of ApPDC. Indole-3-pyruvate does not serve as a substrate for the enzyme. Structural differences occur in two loci, involving the regions Thr341 to Thr352 and Asn499 to Asp503.
CONCLUSIONS
This is the first study of the PDC from G. diazotrophicus (PAL5) and lays the groundwork for future research into its role in this endosymbiont. The crystal structure of GdPDC indicates the enzyme to be evolutionarily closely related to homologues from Z. mobilis and A. pasteurianus and suggests strong selective pressure to keep the enzyme characteristics in a narrow range. The pH optimum together with reduced thermostability likely reflect the host organisms niche and conditions under which these properties have been naturally selected for. The lack of activity on indole-3-pyruvate excludes this decarboxylase as the enzyme responsible for indole acetic acid production in G. diazotrophicus.
Topics: Amino Acids; Bacterial Proteins; Crystallography, X-Ray; Gluconacetobacter; Models, Molecular; Phylogeny; Protein Conformation; Protein Structure, Quaternary; Protein Structure, Tertiary; Pyruvate Decarboxylase; Sarcina; Sequence Homology, Amino Acid; Substrate Specificity; Zymomonas
PubMed: 25369873
DOI: 10.1186/s12900-014-0021-1 -
Journal of Bacteriology Jul 2022species are a major component of the gut microbiome of the fruit fly Drosophila melanogaster, a widely used model organism. While a range of studies have illuminated...
species are a major component of the gut microbiome of the fruit fly Drosophila melanogaster, a widely used model organism. While a range of studies have illuminated impacts of on their hosts, less is known about how association with the host impacts bacteria. A previous study identified that a purine salvage locus was commonly found in associated with . In this study, we sought to verify the functions of predicted purine salvage genes in Acetobacter fabarum DsW_054 and to test the hypothesis that these bacteria can utilize host metabolites as a sole source of nitrogen. Targeted gene deletion and complementation experiments confirmed that genes encoding xanthine dehydrogenase (), urate hydroxylase (), and allantoinase () were required for growth on their respective substrates as the sole source of nitrogen. Utilization of urate by is significant because this substrate is the major nitrogenous waste product of , and its accumulation in the excretory system is detrimental to both flies and humans. The potential significance of our findings for host purine homeostasis and health are discussed, as are the implications for interactions among microbiota members, which differ in their capacity to utilize host metabolites for nitrogen. are commonly found in the gut microbiota of fruit flies, including Drosophila melanogaster. We evaluated the function of purine salvage genes in Acetobacter fabarum to test the hypothesis that this bacterium can utilize host metabolites as a source of nitrogen. Our results identify functions for three genes required for growth on urate, a major host waste product. The utilization of this and other metabolites by gut bacteria may play a role in their survival in the host environment. Future research into how microbial metabolism impacts host purine homeostasis may lead to therapies because urate accumulation in the excretory system is detrimental to flies and humans.
Topics: Acetobacter; Animals; Bacteria; Drosophila melanogaster; Humans; Nitrogen; Uric Acid; Waste Products
PubMed: 35695500
DOI: 10.1128/jb.00041-22 -
Investigacion Y Educacion En Enfermeria Oct 2017To describe the development of the bacterial cellulose coating with anti-inflammatory Ibuprofen (BC/Ibu) and to evaluate the cicatrization process with its use in... (Clinical Trial)
Clinical Trial
OBJECTIVES
To describe the development of the bacterial cellulose coating with anti-inflammatory Ibuprofen (BC/Ibu) and to evaluate the cicatrization process with its use in patients with chronic wounds of venous and diabetic etiology.
METHODS
Longitudinal descriptive study. The cellulose membrane, cultivated with bacteria Gluconacetobacter xylinus and with incorporation of Ibuprofen, was used in the treatment of patients with chronic wounds in public health services in a Brazilian municipality. The ideal coverage characteristics were evaluated through physical, chemical and cell proliferation tests.
RESULTS
The sample consisted of 14 patients (10 women and 4 men), 8 with venous ulcer, 5 with diabetic foot and one with mixed wound. There was reduction of area and pain in 9 lesions; total healing of 3 wounds; and debridement of the devitalized tissue in 5 wounds with increased area. The use of the membrane was important in the reduction of pain, exudation and ease in the accomplishment of the curative.
CONCLUSIONS
BC/Ibu favored the cicatrization process of patients with chronic vasculogenic wounds.
Topics: Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents; Bandages; Cellulose; Chronic Disease; Diabetic Foot; Female; Follow-Up Studies; Gluconacetobacter xylinus; Humans; Ibuprofen; Male; Middle Aged; Treatment Outcome; Varicose Ulcer; Wound Closure Techniques; Wound Healing
PubMed: 29767913
DOI: 10.17533/udea.iee.v35n3a09 -
Annals of Botany Jun 2018Flowers can be highly variable in nectar volume and chemical composition, even within the same plant, but the causes of this variation are not fully understood. One...
BACKGROUND AND AIMS
Flowers can be highly variable in nectar volume and chemical composition, even within the same plant, but the causes of this variation are not fully understood. One potential cause is nectar-colonizing bacteria and yeasts, but experimental tests isolating their effects on wildflowers are largely lacking. This study examines the effects of dominant species of yeasts and bacteria on the hummingbird-pollinated shrub, Mimulus aurantiacus, in California.
METHODS
Wildflowers were inoculated with field-relevant titres of either the yeast Metschnikowia reukaufii or the bacterium Neokomagataea sp. (formerly Gluconobacter sp.), both isolated from M. aurantiacus nectar. Newly opened flowers were bagged, inoculated, harvested after 3 d and analysed for microbial abundance, nectar volume, and sugar and amino acid concentration and composition.
KEY RESULTS
Yeast inoculation reduced amino acid concentration and altered amino acid composition, but had no significant effect on nectar volume or sugar composition. In contrast, bacterial inoculation increased amino acid concentration, enhanced the proportion of nectar sugars comprised by monosaccharides, and reduced nectar volume.
CONCLUSIONS
The results presented suggest that microbial inhabitants of floral nectar can make nectar characteristics variable among flowers through divergent effects of yeasts and bacteria on nectar chemistry and availability, probably modifying plant-pollinator interactions.
Topics: Amino Acids; Flowers; Gluconobacter; Metschnikowia; Mimulus; Plant Nectar; Sugars
PubMed: 29562323
DOI: 10.1093/aob/mcy032 -
Microbial Ecology Jan 2019Plant litter decomposition is a process enabling biogeochemical cycles closing in ecosystems, and decomposition in forests constitutes the largest part of this process...
Plant litter decomposition is a process enabling biogeochemical cycles closing in ecosystems, and decomposition in forests constitutes the largest part of this process taking place in terrestrial biomes. Microbial communities during litter decomposition were studied mainly with low-throughput techniques not allowing detailed insight, particularly into coniferous litter, as it is more difficult to obtain high quality DNA required for analyses. Motivated by these problems, we analyzed archaeal, bacterial, and eukaryotic communities at three decomposition stages: fresh, 3- and 8-month-old litter by 16/18S rDNA pyrosequencing, aiming at detailed insight into early stages of pine litter decomposition. Archaea were absent from our libraries. Bacterial and eukaryotic diversity was greatest in 8-month-old litter and the same applied to bacterial and fungal rDNA content. Community structure was different at various stages of decomposition, and phyllospheric organisms (bacteria: Acetobacteraceae and Pseudomonadaceae members, fungi: Lophodermium, Phoma) were replaced by communities with metabolic capabilities adapted to the particular stage of decomposition. Sphingomonadaceae and Xanthomonadaceae and fungal genera Sistotrema, Ceuthospora, and Athelia were characteristic for 3-month-old samples, while 8-month-old ones were characterized by Bradyrhizobiaceae and nematodes (Plectus). We suggest that bacterial and eukaryotic decomposer communities change at different stages of pine litter decomposition in a way similar to that in broadleaf litter. Interactions between bacteria and eukaryotes appear to be one of the key drivers of microbial community structure.
Topics: Archaea; Bacteria; Biodiversity; DNA; DNA, Ribosomal; Decompression; Ecosystem; Eukaryota; Fungi; Metagenomics; Microbiota; Pinus; RNA, Ribosomal, 16S; RNA, Ribosomal, 18S; Soil Microbiology; Trees
PubMed: 29850933
DOI: 10.1007/s00248-018-1209-x