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BMC Genomics Dec 2022European foulbrood is a significant bacterial brood disease of Apis sp. and can cause severe and devastating damages in beekeeping operations. Nevertheless, the...
BACKGROUND
European foulbrood is a significant bacterial brood disease of Apis sp. and can cause severe and devastating damages in beekeeping operations. Nevertheless, the epidemiology of its causative agent Melissococcus plutonius has been begun to uncover but the underlying mechanisms of infection and cause of disease still is not well understood. Here, we sought to provide insight into the infection mechanism of EFB employing RNAseq in in vitro reared Apis mellifera larvae of two developmental stages to trace transcriptional changes in the course of the disease, including Paenibacillus alvei secondary infected individuals.
RESULTS
In consideration of the progressing development of the larva, we show that infected individuals incur a shift in metabolic and structural protein-encoding genes, which are involved in metabolism of crucial compounds including all branches of macronutrient metabolism, transport protein genes and most strikingly chitin and cuticle associated genes. These changes underpin the frequently observed developmental retardation in EFB disease. Further, sets of expressed genes markedly differ in different stages of infection with almost no overlap. In an earlier stage of infection, a group of regulators of the melanization response cascade and complement component-like genes, predominantly C-type lectin genes, are up-regulated while a differential expression of immune effector genes is completely missing. In contrast, late-stage infected larvae up-regulated the expression of antimicrobial peptides, lysozymes and prominent bacteria-binding haemocyte receptor genes compared to controls. While we clearly show a significant effect of infection on expressed genes, these changes may partly result from a shift in expression timing due to developmental alterations of infection. A secondary infection with P. alvei elicits a specific response with most of the M. plutonius associated differential immune effector gene expression missing and several immune pathway genes even down-regulated.
CONCLUSION
We conclude that with progressing infection diseased individuals undergo a systemic response with a change of metabolism and their activated immune defence repertoire. Moreover, larvae are capable of adjusting their response to a secondary invasion in late stage infections.
Topics: Animals; Bacillus; Bacterial Infections; Bees; Larva; Transcriptome
PubMed: 36536278
DOI: 10.1186/s12864-022-09075-6 -
Toxins Oct 2021Food bio-preservatives are requested as substituents of chemical pesticides in food. The aim of this study was to carry out a screening of twenty biocontrol agents...
Food bio-preservatives are requested as substituents of chemical pesticides in food. The aim of this study was to carry out a screening of twenty biocontrol agents (BCAs) for their potential fungicidal activity in vitro. Twenty BCAs were tested against ten pathogenic fungi. Some of the cell-free supernatants (CFS) tested showed in vitro antifungal activity versus pathogenic fungi. The highest fungicidal activity was observed in the fermented CFS of CECT 375, CECT 493, and CECT 850, which showed a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of 125 and 250 g/L, respectively. The compounds responsible for the antifungal activity, such as organic and phenolic acids, were determined. Lactic acid, acetic acid, benzoic acid, and phenyllactic acid among others can be related to antifungal activity. HPLC-MS/MS analysis showed a reduction of ochratoxin A (OTA) and aflatoxin B (AFB) up to 26% ( CECT 2) and 55% ( CECT 155), respectively. The present study prompts that metabolism products of BCAs are propitious for the bioconservation of food, due to their ability to reduce the proliferation of mycotoxigenic fungi and mycotoxins production.
Topics: Aflatoxin B1; Antifungal Agents; Bacillus amyloliquefaciens; Cell-Free System; Fungicides, Industrial; In Vitro Techniques; Ochratoxins; Paenibacillus; Pantoea; Pest Control, Biological; Poisons
PubMed: 34822536
DOI: 10.3390/toxins13110752 -
Plants (Basel, Switzerland) May 2021Grapevine bunch rot, caused by and , causes important economic losses every year in grape production. In the present study, we examined the plant protective activity of...
Grapevine bunch rot, caused by and , causes important economic losses every year in grape production. In the present study, we examined the plant protective activity of the biological control agents, K165, sp. FP12 and sp. FP15 against and on grapes. The in vitro experiments showed that strain K165 significantly reduced the growth of both fungi, while FP15 restricted the growth of and FP12 was ineffective. Following the in vitro experiments, we conducted in planta experiments on grape berries. It was shown that K165, FP12 and FP15 reduced rot severity by 81%, 57% and 37%, respectively, compared to the control, whereas, in the case of , the only protective treatment was that with K165, which reduced rot by 75%. The transcriptomic analysis of the genes encoding the pathogenesis-related proteins PR2, PR3, PR4 and PR5 indicates the activation of multiple defense responses involved in the biocontrol activity of the examined biocontrol agents.
PubMed: 34068090
DOI: 10.3390/plants10050970 -
Advanced Science (Weinheim,... Feb 2024Post-translational prenylations, found in eukaryotic primary metabolites and bacterial secondary metabolites, play crucial roles in biomolecular interactions. Employing...
Post-translational prenylations, found in eukaryotic primary metabolites and bacterial secondary metabolites, play crucial roles in biomolecular interactions. Employing genome mining methods combined with AlphaFold2-based predictions of protein interactions, PalQ , a prenyltransferase responsible for the tryptophan prenylation of RiPPs produced by Paenibacillus alvei, is identified. PalQ differs from cyanobactin prenyltransferases because of its evolutionary relationship to isoprene synthases, which enables PalQ to transfer extended prenyl chains to the indole C3 position. This prenylation introduces structural diversity to the tryptophan side chain and also leads to conformational dynamics in the peptide backbone, attributed to the cis/trans isomerization that arises from the formation of a pyrrolidine ring. Additionally, PalQ exhibited pronounced positional selectivity for the C-terminal tryptophan. Such enzymatic characteristics offer a toolkit for peptide therapeutic lipidation.
Topics: Dimethylallyltranstransferase; Tryptophan; Prenylation; Protein Processing, Post-Translational; Peptides
PubMed: 38059776
DOI: 10.1002/advs.202307372 -
Journal of Applied Microbiology Sep 2021This research investigated the influence of soil microbiota on Escherichia coli O157:H7 survival in soil rinse and artificial soil. Additionally, the influence of...
AIMS
This research investigated the influence of soil microbiota on Escherichia coli O157:H7 survival in soil rinse and artificial soil. Additionally, the influence of selected soil bacteria on E. coli O157:H7 in soil environments was determined.
METHODS AND RESULTS
Escherichia coli O157:H7 counts (log CFU per ml or g ) were determined by spread plating: (i) artificial soil amended with soil rinse (filter-sterilized and unfiltered) at 30°C; (ii) unfiltered soil rinse (50 ml) treated with cycloheximide (200 μg ml ), vancomycin (40 μg ml ), heat (80°C, 15 min) and no treatment (control) for 7 days at 30°C and (iii) filtered soil rinse with selected soil bacterial isolates over 7 days. There was a significant difference (P = 0·027) in E. coli O157:H7 counts after 35 days between artificial soils amended with filtered (4·45 ± 0·29) and non-filtered (1·83 ± 0·33) soil rinse. There were significant differences (P < 0·05) in E. coli O157:H7 counts after 3 days of incubation between soil rinse treatments (heat (7·04 ± 0·03), cycloheximide (6·94 ± 0·05), vancomycin (4·26 ± 0·98) and control (5·00 ± 0·93)). Lastly, a significant difference (P < 0·05) in E. coli O157:H7 counts was observed after 3 days of incubation at 30°C in filtered soil rinse when incubated with Paenibacillus alvei versus other soil bacterial isolates evaluated.
CONCLUSIONS
Soil microbiota isolated from Florida sandy soil influenced E. coli O157:H7 survival. Specifically, P. alvei reduced E. coli O157:H7 by over 3 log CFU per ml after 3 days of incubation at 30°C in filtered soil rinse.
SIGNIFICANCE AND IMPACT OF THE STUDY
This research identified soil bacterial isolates that may reduce E. coli O157:H7 in the soil environment and be used in future biocontrol applications.
Topics: Antibiosis; Biological Control Agents; Colony Count, Microbial; Escherichia coli O157; Florida; Food Microbiology; Paenibacillus; Soil; Soil Microbiology
PubMed: 33583119
DOI: 10.1111/jam.15039 -
Virulence Dec 2020is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence,...
is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence, and understanding the mechanisms influencing virulence may allow for improved disease control and containment. Using a standardized assay, we demonstrate that virulence varies greatly among sixteen isolates from five European countries. Additionally, we explore the causes of this variation. In this study, virulence was independent of the multilocus sequence type of the tested pathogen, and was not affected by experimental co-infection with , a bacterium often associated with EFB outbreaks. Virulence was correlated with the growth dynamics of isolates in artificial medium, and with the presence of a plasmid carrying a gene coding for the putative toxin melissotoxin A. Our results suggest that some strains showed an increased virulence due to the acquisition of a toxin-carrying mobile genetic element. We discuss whether strains with increased virulence play a role in recent EFB outbreaks.
Topics: Animals; Bacterial Toxins; Bacterial Typing Techniques; Bees; Enterococcaceae; Gram-Positive Bacterial Infections; Interspersed Repetitive Sequences; Larva; Multilocus Sequence Typing; Plasmids; Virulence
PubMed: 32456539
DOI: 10.1080/21505594.2020.1768338 -
Plants (Basel, Switzerland) Jul 2021Plant growth-promoting rhizobacteria (PGPR) can stimulate disease suppression through the induction of an enhanced state of defense readiness. Here, untargeted...
Plant growth-promoting rhizobacteria (PGPR) can stimulate disease suppression through the induction of an enhanced state of defense readiness. Here, untargeted ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and targeted ultra-high performance liquid chromatography coupled to triple-quadrupole mass spectrometry (UHPLC-QqQ-MS) were used to investigate metabolic reprogramming in tomato plant tissues in response to priming by N04 and T22 against . Roots were treated with the two PGPR strains prior to stem inoculation with Metabolites were methanol-extracted from roots, stems and leaves at two-eight days post-inoculation. Targeted analysis by UHPLC-QqQ-MS allowed quantification of aromatic amino acids and phytohormones. For untargeted analysis, UHPLC-MS data were chemometrically processed to determine signatory biomarkers related to priming against . The aromatic amino acid content was differentially reprogrammed in and primed plants responding to . Furthermore, abscisic acid and methyl salicylic acid were found to be major signaling molecules in the tripartite interaction. LC-MS metabolomics analysis showed time-dependent metabolic changes in the primed-unchallenged vs. primed-challenged tissues. The annotated metabolites included phenylpropanoids, benzoic acids, glycoalkaloids, flavonoids, amino acids, organic acids, as well as oxygenated fatty acids. Tissue-specific reprogramming across diverse metabolic networks in roots, stems and leaves was also observed, which demonstrated that PGPR priming resulted in modulation of the defense response to infection.
PubMed: 34451575
DOI: 10.3390/plants10081530 -
Biotechnology Letters Apr 2024Microbial pretreatment of lignocellulosic biomass holds significant promise for environmentally friendly biofuel production, offering an alternative to fossil fuels....
Microbial pretreatment of lignocellulosic biomass holds significant promise for environmentally friendly biofuel production, offering an alternative to fossil fuels. This study focused on the isolation and characterization of two novel delignifying bacteria, GIET1 and GIET2, to enhance cellulose accessibility by lignin degradation. Molecular characterization confirmed their genetic identities, providing valuable microbial resources for biofuel production. Our results revealed distinct preferences for temperature, pH, and incubation period for the two bacteria. Bacillus haynesii exhibited optimal performance under moderate conditions and shorter incubation period, making it suitable for rice straw and sugarcane bagasse pretreatment. In contrast, Paenibacillus alvei thrived at higher temperatures and slightly alkaline pH, requiring a longer incubation period ideal for corn stalk pretreatment. These strain-specific requirements highlight the importance of tailoring pretreatment conditions to specific feedstocks. Structural, chemical, and morphological analyses demonstrated that microbial pretreatment reduced the amorphous lignin, increasing cellulose crystallinity and accessibility. These findings underscore the potential of microbial pretreatment to enhance biofuel production by modifying the lignocellulosic biomass. Such environmentally friendly bioconversion processes offer sustainable and cleaner energy solutions. Further research to optimize these methods for scalability and broader application is necessary in the pursuit for more efficient and greener biofuel production.
Topics: Lignin; Cellulose; Biomass; Biofuels; Saccharum; Hydrolysis
PubMed: 38252364
DOI: 10.1007/s10529-023-03463-y -
Glycobiology Jun 2010Glycosylation is a frequent and heterogeneous posttranslational protein modification occurring in all domains of life. While protein N-glycosylation at asparagine and...
Glycosylation is a frequent and heterogeneous posttranslational protein modification occurring in all domains of life. While protein N-glycosylation at asparagine and O-glycosylation at serine, threonine or hydroxyproline residues have been studied in great detail, only few data are available on O-glycosidic attachment of glycans to the amino acid tyrosine. In this study, we describe the identification and characterization of a bacterial protein tyrosine O-glycosylation system. In the Gram-positive, mesophilic bacterium Paenibacillus alvei CCM 2051(T), a polysaccharide consisting of [-->3)-beta-d-Galp-(1[alpha-d-Glcp-(1-->6)] -->4)-beta-d-ManpNAc-(1-->] repeating units is O-glycosidically linked via an adaptor with the structure -[GroA-2-->OPO(2)-->4-beta-d-ManpNAc-(1-->4)] -->3)-alpha-l-Rhap-(1-->3)-alpha-l-Rhap-(1-->3)-alpha-l-Rhap-(1-->3)-beta-d-Galp-(1--> to specific tyrosine residues of the S-layer protein SpaA. A +AH4-24.3-kb S-layer glycosylation (slg) gene cluster encodes the information necessary for the biosynthesis of this glycan chain within 18 open reading frames (ORF). The corresponding translation products are involved in the biosynthesis of nucleotide-activated monosaccharides, assembly and export as well as in the transfer of the completed polysaccharide chain to the S-layer target protein. All ORFs of the cluster, except those encoding the nucleotide sugar biosynthesis enzymes and the ATP binding cassette (ABC) transporter integral transmembrane proteins, were disrupted by the insertion of the mobile group II intron Ll.LtrB, and S-layer glycoproteins produced in mutant backgrounds were analyzed by mass spectrometry. There is evidence that the glycan chain is synthesized in a process comparable to the ABC-transporter-dependent pathway of the lipopolysaccharide O-polysaccharide biosynthesis. Furthermore, with the protein WsfB, we have identified an O-oligosaccharyl:protein transferase required for the formation of the covalent beta-d-Gal-->Tyr linkage between the glycan chain and the S-layer protein.
Topics: Bacillus; Bacterial Proteins; Glycosylation; Mutation; Polysaccharides; Reverse Transcriptase Polymerase Chain Reaction; Tyrosine
PubMed: 20200052
DOI: 10.1093/glycob/cwq035 -
Frontiers in Plant Science 2023Plant-microbe interactions are a phenomenal display of symbiotic/parasitic relationships between living organisms. Plant growth-promoting rhizobacteria (PGPR) are some...
Plant-microbe interactions are a phenomenal display of symbiotic/parasitic relationships between living organisms. Plant growth-promoting rhizobacteria (PGPR) are some of the most widely investigated plant-beneficial microbes due to their capabilities in stimulating plant growth and development and conferring protection to plants against biotic and abiotic stresses. As such, PGPR-mediated plant priming/induced systemic resistance (ISR) has become a hot topic among researchers, particularly with prospects of applications in sustainable agriculture. The current study applies untargeted ultra-high performance liquid chromatography-high-definition mass spectrometry (UHPLC-HDMS) to investigate PGPR-based metabolic reconfigurations in the metabolome of primed wheat plants against f. sp. (). A seed bio-priming approach was adopted, where seeds were coated with two PGPR strains namely and (T22) and grown under controlled conditions in a glasshouse. The plants were infected with one-week post-germination, followed by weekly harvesting of leaf material. Subsequent metabolite extraction was carried out for analysis on a UHPLC-HDMS system for data acquisition. The data was chemometrically processed to reveal the underlying trends and data structures as well as potential signatory biomarkers for priming against . Results showed notable metabolic reprogramming in primary and secondary metabolism, where the amino acid and organic acid content of primed-control, primed-challenged and non-primed-challenged plants were differentially reprogrammed. Similar trends were observed from the secondary metabolism, in which primed plants (particularly primed-challenged) showed an up-regulation of phenolic compounds (flavonoids, hydroxycinnamic acids-HCAs- and HCA amides) compared to the non-primed plants. The metabolomics-based semi-quantitative and qualitative assessment of the plant metabolomes revealed a time-dependent metabolic reprogramming in primed-challenged and primed-unchallenged plants, indicating the metabolic adaptations of the plants to stripe rust infection over time.
PubMed: 37123830
DOI: 10.3389/fpls.2023.1103413