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MBio Apr 2024The natural microbiota isolates MYb11 and MYb115 protect the host against pathogens through distinct mechanisms. While produces an antimicrobial compound and...
The natural microbiota isolates MYb11 and MYb115 protect the host against pathogens through distinct mechanisms. While produces an antimicrobial compound and directly inhibits pathogen growth, MYb115 protects the host without affecting pathogen growth. It is unknown how these two protective microbes affect host biological processes. We used a proteomics approach to elucidate the response to MYb11 and MYb115. We found that both isolates increase vitellogenin protein production in young adults, which confirms previous findings on the effect of microbiota on reproductive timing. Moreover, the responses to MYb11 and MYb115 exhibit common signatures with the response to other vitamin B-producing bacteria, emphasizing the importance of vitamin B in -microbe metabolic interactions. We further analyzed signatures in the response specific to MYb11 or MYb115. We provide evidence for distinct modifications in lipid metabolism by both symbiotic microbes. We could identify the activation of host-pathogen defense responses as an MYb11-specific proteome signature and provide evidence that the intermediate filament protein IFB-2 is required for MYb115-mediated protection. These results indicate that MYb11 not only produces an antimicrobial compound but also activates host antimicrobial defenses, which together might increase resistance to infection. In contrast, MYb115 affects host processes such as lipid metabolism and cytoskeleton dynamics, which might increase host tolerance to infection. Overall, this study pinpoints proteins of interest that form the basis for additional exploration into the mechanisms underlying microbiota-mediated protection from pathogen infection and other microbiota-mediated traits.IMPORTANCESymbiotic bacteria can defend their host against pathogen infection. While some protective symbionts directly interact with pathogenic bacteria, other protective symbionts elicit a response in the host that improves its own pathogen defenses. To better understand how a host responds to protective symbionts, we examined which host proteins are affected by two protective bacteria in the model nematode . We found that the response to its protective symbionts is manifold, which was reflected in changes in proteins that are involved in metabolism, the immune system, and cell structure. This study provides a foundation for exploring the contribution of the host response to symbiont-mediated protection from pathogen infection.
Topics: Animals; Caenorhabditis elegans; Proteome; Pseudomonas; Caenorhabditis elegans Proteins; Anti-Infective Agents; Vitamins
PubMed: 38411078
DOI: 10.1128/mbio.03463-23 -
BMC Microbiology Aug 2023In recent years, the demand for innovative antimicrobial agents has grown, considering the growing problem of antibiotic resistance in aquaculture. Adult Apis mellifera...
BACKGROUND
In recent years, the demand for innovative antimicrobial agents has grown, considering the growing problem of antibiotic resistance in aquaculture. Adult Apis mellifera honeybees' gut represents an outstanding habitat to isolate novel lactic acid bacteria (LAB) able to produce prominent antimicrobial agents.
METHODS
In the current study, twelve LAB were isolated and purified from the gut of adult Apis mellifera. The isolates were screened for exopolysaccharide (EPS) production. The most promising isolate BE11 was identified biochemically and molecularly using 16 S rRNA gene sequence analysis as Enterococcus sp. BE11 was used for the mass production of EPS. The partially purified BE11-EPS features were disclosed by its physicochemical characterization. Moreover, the antimicrobial activity of BE11 cell free supernatant (CFS) and its EPS was investigated against some fish pathogens namely, Pseudomonas fluorescens, Streptococcus agalactiae, Aeromonas hydrophila, Vibrio sp. and Staphylococcus epidermidis using well-cut diffusion method.
RESULTS
The physicochemical characterization of BE11-EPS revealed that the total carbohydrate content was estimated to be ~ 87%. FTIR and NMR analysis ascertained the presence of galactose and glucose residues in the EPS backbone. Moreover, the GC-MS analysis verified the heterogeneous nature of the produced BE11-EPS made up of different monosaccharide moieties: galactose, rhamnose, glucose, arabinose sugar derivatives, and glucuronic acid. BE11 CFS and its EPS showed promising antimicrobial activity against tested pathogens as the inhibition zone diameters (cm) ranged from 1.3 to 1.7 and 1.2-1.8, respectively.
CONCLUSION
The bee gut-resident Enterococcus sp. BE11, CFS, and EPS were found to be promising antimicrobial agents against fish pathogens and biofilm producers affecting aquaculture. To the best of our knowledge, this is the first study to purify and make a chemical profile of an EPS produced by a member of the bee gut microbiota as a potential inhibitor for fish pathogens.
Topics: Bees; Animals; Galactose; Anti-Bacterial Agents; Aeromonas hydrophila; Enterococcus; Fishes; Glucose; Lactobacillales
PubMed: 37612642
DOI: 10.1186/s12866-023-02977-9 -
BioRxiv : the Preprint Server For... Oct 2023We present a high-resolution 1D and 2D magic-angle spinning (MAS) solid-state NMR (ssNMR) study to characterize native colony biofilms at natural abundance without...
We present a high-resolution 1D and 2D magic-angle spinning (MAS) solid-state NMR (ssNMR) study to characterize native colony biofilms at natural abundance without isotope-labelling. By using a high-resolution INEPT-based 2D H- C ssNMR spectrum and thorough peak deconvolution approach at the 1D ssNMR spectra, approximately 80/134 (in 1D/2D) distinct biofilm chemical sites were identified. We compared CP and INEPT C ssNMR spectra to different signals originating from the mobile and rigid fractions of the biofilm, and qualitative determined dynamical changes by comparing CP buildup behaviors. Protein and polysaccharide signals were differentiated and identified by utilizing FapC signals as a template, a biofilm forming functional amyloid from . We also attempted to identify biofilm polysaccharide species by using H/ C chemical shifts obtained from the 2D spectrum. This study marks the first demonstration of high-resolution 2D ssNMR spectroscopy for characterizing native bacterial biofilms and expands the scope of ssNMR in studying biofilms. Our experimental pipeline can be readily applied to other in vitro biofilm model systems and natural biofilms and holds the promise of making a substantial impact on biofilm research, fostering new ideas and breakthroughs to aid in the development of strategic approaches to combat infections caused by biofilm-forming bacteria.
PubMed: 37873242
DOI: 10.1101/2023.10.02.560490 -
ACS Omega Nov 2023Agronomic management of a crop, including the application of fertilizers and biological inoculants, affects the phenol and flavonoid contents of plants producing these...
Agronomic management of a crop, including the application of fertilizers and biological inoculants, affects the phenol and flavonoid contents of plants producing these metabolites. Kunth, a woody bamboo widely distributed in the Americas, produces several biologically active phenolic compounds. The aim of this study was to evaluate the effect of chemical and organic fertilizers together with the application of biological inoculants on the composition of phenolic compounds in plants at the nursery stage. In 8-month-old plants, differences were observed in plant biomass (20.27 ± 7.68 g) and in the content of total phenols and flavonoids (21.89 ± 9.64 mg gallic acid equivalents/plant and 2.13 ± 0.98 mg quercetin equivalents/plant, respectively) when using the chemical fertilizer diammonium phosphate (DAP). No significant differences were found owing to the effect of the inoculants, although the plants with the application of sp. on plants fertilized with DAP presented higher values of the metabolites (24.12 ± 6.72 mg gallic acid equivalents/plant and 2.39 ± 0.77 mg quercetin equivalents/plant). The chromatographic profile of phenolic metabolites is dominated by one glycosylated flavonoid, the concentration of which was favored by the application of the inoculants , , and sp. In the case study, the combined use of DAP and bacterial inoculants is recommended for the production of plant material with a high content of promising biologically active flavonoids or phenolics.
PubMed: 37970062
DOI: 10.1021/acsomega.3c04579 -
Microbial Cell Factories May 2024Aminopyrrolnitrin (APRN), a natural halogenated phenylpyrrole derivative (HPD), has strong antifungal and antiparasitic activities. Additionally, it showed 2.8-fold...
Aminopyrrolnitrin (APRN), a natural halogenated phenylpyrrole derivative (HPD), has strong antifungal and antiparasitic activities. Additionally, it showed 2.8-fold increased photostability compared to pyrrolnitrin, a commercially available HPD with antimicrobial activity. For microbial production of APRN, we first engineered anthranilate phosphoribosyltransferase encoded by trpD from Corynebacterium glutamicum, resulting in a TrpD mutation that exhibits feedback-resistant against L-tryptophan and higher substrate affinity compared to wild-type TrpD. Plasmid-borne expression of trpD in C. glutamicum TP851 strain with two copies of trpD in the genome led to the production of 3.1 g/L L-tryptophan in flask culture. Subsequent step for L-tryptophan chlorination into 7-chloro-L-tryptophan was achieved by introducing diverse sources of genes encoding tryptophan 7-halogenase (PrnA or RebH) and flavin reductase (Fre, PrnF, or RebF). The combined expression of prnA from Serratia grimesii or Serratia plymuthica with flavin reductase gene from Escherichia coli, Pseudomonas fluorescens, or Lechevalieria aerocolonigenes yielded higher production of 7-chloro-L-tryptophan in comparison to other sets of two-component systems. In the next step, production of putative monodechloroaminopyrrolnitrin (MDAP) from 7-chloro-L-tryptophan was achieved through the expression of prnB encoding MDAP synthase from S. plymuthica or P. fluorescens. Finally, an artificial APRN biosynthetic pathway was constructed by simultaneously expressing genes coding for tryptophan 7-halogenase, flavin reductase, MDAP synthase, and MDAP halogenase (PrnC) from different microbial sources within the L-tryptophan-producing TP851 strain. As prnC from S. grimesii or S. plymuthica was introduced into the host strain, which carried plasmids expressing prnA from S. plymuthica, fre from E. coli, and prnB from S. plymuthica, APN3639 and APN3638 accumulated 29.5 mg/L and 28.1 mg/L of APRN in the culture broth. This study represents the first report on the fermentative APRN production by metabolically engineered C. glutamicum.
Topics: Corynebacterium glutamicum; Metabolic Engineering; Pyrrolnitrin; Fermentation; Bacterial Proteins; Tryptophan; Escherichia coli; Oxidoreductases
PubMed: 38783320
DOI: 10.1186/s12934-024-02424-y -
Heliyon Jul 2023This study was undertaken to see how microbial consortia influenced maize development and yield under salt-affected conditions. The efficacy of the pre-isolated...
Plant growth-promoting bacterial consortia improved the physiology and growth of maize by regulating osmolytes and antioxidants balance under salt-affected field conditions.
This study was undertaken to see how microbial consortia influenced maize development and yield under salt-affected conditions. The efficacy of the pre-isolated bacterial strains , , , and to decrease the detrimental effects of salt on maize was tested in four distinct combinations using Randomized Complete Block Design with three replicates. The results revealed that these strains were compatible and collaborated synergistically, with an 80% co-aggregation percentage under salt-affected conditions. Following that, these strains were tested for their ability to increase maize growth and yield under salt-affected field conditions. The photosynthetic rate (11-50%), relative water content (10-34%), and grain yield (13-21%) of maize were all increased by these various combinations. However, when , and were combined, the greatest increase was seen above the un-inoculated control. Furthermore, as compared to the un-inoculated control, the same combination resulted in a 1.5-fold increase in catalase and a 2.0-fold increase in ascorbate concentration. These findings showed that a multi-strain consortium might boost maize's total yield response as a result of better growth under salt stress.
PubMed: 37483786
DOI: 10.1016/j.heliyon.2023.e17816 -
International Journal of Molecular... Apr 2024Molecular studies about cyanide biodegradation have been mainly focused on the hydrolytic pathways catalyzed by the cyanide dihydratase CynD or the nitrilase NitC. In...
Molecular studies about cyanide biodegradation have been mainly focused on the hydrolytic pathways catalyzed by the cyanide dihydratase CynD or the nitrilase NitC. In some strains, the assimilation of cyanide has been linked to NitC, such as the cyanotrophic model strain CECT 5344, which has been recently reclassified as CECT 5344. In this work, a phylogenomic approach established a more precise taxonomic position of the strain CECT 5344 within the species . Furthermore, a pan-genomic analysis of and other species with cyanotrophic strains, such as and , allowed for the comparison and identification of the and genes involved in cyanide resistance, and the and genes required for the assimilation of cyanide or cyanate, respectively. While cyanide resistance genes presented a high frequency among the analyzed genomes, genes responsible for cyanide or cyanate assimilation were identified in a considerably lower proportion. According to the results obtained in this work, an in silico approach based on a comparative genomic approach can be considered as an agile strategy for the bioprospection of putative cyanotrophic bacteria and for the identification of new genes putatively involved in cyanide biodegradation.
Topics: Cyanides; Biodegradation, Environmental; Pseudomonas; Phylogeny; Genome, Bacterial; Genomics; Bacterial Proteins; Aminohydrolases; Pseudomonas pseudoalcaligenes
PubMed: 38674043
DOI: 10.3390/ijms25084456 -
BMC Ecology and Evolution Sep 2023Intraspecific public goods are commonly shared within microbial populations, where the benefits of public goods are largely limited to closely related conspecifics. One...
BACKGROUND
Intraspecific public goods are commonly shared within microbial populations, where the benefits of public goods are largely limited to closely related conspecifics. One example is the production of iron-scavenging siderophores that deliver iron to cells via specific cell envelope receptor and transport systems. Intraspecific social exploitation of siderophore producers is common, since non-producers avoid the costs of production but retain the cell envelope machinery for siderophore uptake. However, little is known about how interactions between species (i.e., interspecific interactions) can shape intraspecific public goods exploitation. Here, we predicted that strong competition for iron between species in diverse communities will increase costs of siderophore cooperation, and hence drive intraspecific exploitation. We examined how increasing microbial community species diversity shapes intraspecific social dynamics by monitoring the growth of siderophore producers and non-producers of the plant-growth promoting bacterium Pseudomonas fluorescens, embedded within tree-hole microbial communities ranging from 2 to 15 species.
RESULTS
We find, contrary to our prediction, that siderophore production is favoured at higher levels of community species richness, driven by increased likelihood of encountering key species that reduce the growth of siderophore non-producing (but not producing) strains of P. fluorescens.
CONCLUSIONS
Our results suggest that maintaining a diverse soil microbiota could partly contribute to the maintenance of siderophore production in natural communities.
Topics: Siderophores; Iron; Biological Transport; Cell Membrane; Pseudomonas fluorescens
PubMed: 37658316
DOI: 10.1186/s12862-023-02152-8 -
ACS Omega Feb 2024Microbial degradation of dyes is vital to understanding the fate of dyes in the environment. In this study, a fungal strain A-3 and a bacterial strain L-6, which were...
Microbial degradation of dyes is vital to understanding the fate of dyes in the environment. In this study, a fungal strain A-3 and a bacterial strain L-6, which were identified as and , respectively, had been proven to efficiently degrade crystal violet (CV) dye. The decolorization of CV dye by fungal and bacterial cocultivation was investigated. The results showed that the decolorization rate of cocultures was better than monoculture ( in L-6 (PF), and that of A-3 (AF)). Furthermore, enzymatic analysis further revealed that Lac, MnP, Lip, and NADH-DCIP reductases were involved in the biodegradation of CV dyes. UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) were used to examine the degradation products. GC-MS analysis showed the presence of 4-(dimethylamino) benzophenone, 3-dimethylaminophenol, benzyl alcohol, and benzaldehyde, indicating that CV was degraded into simpler compounds. The phytotoxicity tests revealed that CV degradation products were less toxic than the parent compounds, indicating that the cocultures detoxified CV dyes. As a result, the cocultures are likely to have a wide range of applications in the bioremediation of CV dyes.
PubMed: 38405495
DOI: 10.1021/acsomega.3c06978 -
Nanomaterials (Basel, Switzerland) Dec 2023This work studies the antimicrobial activity of benzyldimethyldodecyl ammonium chloride (BDMDAC)-coated microparticles with distinct morphological structures....
This work studies the antimicrobial activity of benzyldimethyldodecyl ammonium chloride (BDMDAC)-coated microparticles with distinct morphological structures. Functionalized microparticles were prepared by the layer-by-layer (LbL) self-assembly technique on hydroxyapatite (Hap), calcium carbonate (CaCO) and glass beads (GB) cores. All particles were characterized, before and after functionalization, by Fourier-Transform Infrared Spectroscopy (FTIR), Brunner-Emmett-Teller (BET) and Scanning Electron Microscopy (SEM) analyses. Antimicrobial activity was tested against planktonic . Planktonic bacteria were exposed to 100 mg/L, 200 mg/L and 400 mg/L of BDMDAC-coated microparticles for 240 min. This strategy promoted a complete bacteria reduction at 200 mg/L for Hap microparticles after 240 min. No release of biocide was detected through HPLC analyses during 2 weeks, suggesting that bacteria inactivation may be attributed to a contact killing mechanism.
PubMed: 38063763
DOI: 10.3390/nano13233067