| 1. |
- Styriak, I, et al.
(författare)
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Lectin-like binding and antibiotic sensitivity of enterococci from wild herbivores
- 2002
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Ingår i: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 157:4, s. 293-303
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Tidskriftsartikel (refereegranskat)abstract
- Fifty eight enterococcal isolates from wild herbivores were tested for their antibiotic sensitivity pattern and lectin-like binding of extracellular matrix (ECM) and serum proteins. Kanamycin resistance was very frequent; many multiresistant strains were also isolated. All isolates were sensitive to rifampicin. Resistance to gentamicin, novobiocin, and tetracycline was widely distributed in the microflora of wild herbivores breeded in zoological garden in Kosice. No autoaggregating strains were detected among these 58 enterococcal isolates. Various degrees of binding of mucins, fetuin, heparin, fibrinogen, and fibronectin were observed in individual strains. However, bovine lactoferrin binding by enterococci from deers and chamoises was either negative (0) or strongly positive (3). With regard to influence of growth media, TH agar was found to be better for the expression of lectin-like binding than blood agar, TH broth and Nutrient broth. A significant effect (P < 0.001 or P < 0.05) of proteolytic treatment was observed in six selected strains. However, there is a difference between the effect of trypsin and pronase P. Pronase treatment more effectively decreased binding of some strains (1H, 6A, EF 1111, EC 1292), while trypsin treatment decreased more binding of other enterococcal strains (EF 953 and 1E). Significant (P < 0.001) influence of metaperiodate, which cleaves the C-C bond between vicinal groups of sugars, on collagen I binding by three selected strains (1E, 1H, 6A) and bovine lactoferrin binding (by EF 1111, EC 1292, EF 953) was also observed. However, its influence was very different. In two strains (1H and EC 1292), ECM binding was decreased, while in four other strains (1E, 6A, EF 1111, EF 953) it was increased.
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| 2. |
- Andersson, Sofia, et al.
(författare)
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Influence of microbial interactions and EPS/polysaccharide composition on nutrient removal activity in biofilms formed by strains found in wastewater treatment systems
- 2011
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 166:6, s. 449-457
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Tidskriftsartikel (refereegranskat)abstract
- The study of biofilm function, structure and microbial interactions might help to improve our understanding of biofilm wastewater treatment processes. However, few reports specifically address the influence of interactions within multispecies biofilms on microbial activity and biofilm composition. Thus, the relationship between biofilm formation, denitrification activity, phosphorus removal and the composition of extracellular polymeric substances (EPS), exopolysaccharides and the bacterial community was investigated using biofilms of denitrifying and phosphorus removing strains Comamonas denitrificans 110, Brachymonas denitrificans B79, Aeromonas hydrophila L6 and Acinetobacter calcoaceticus ATCC23055. Denitrification activity within the biofilms generally increased with the amount of biofilm while phosphorus removal depended on bacterial growth rate. Synergistic effects of co-growth on denitrification (B. denitrificans B79 and A. hydrophila L6) and phosphorus removal (C. denitrificans 110 with either A. calcoaceticus or A. hydrophila L6) were observed. B. denitrificans B79 was highly affected by interspecies interactions with respect to biofilm formation, denitrification activity and EPS composition, while C. denitrificans 110 remained largely unaffected. In some of the dual and quadruple strain biofilms new exopolysaccharide monomers were detected which were not present in the pure strain samples.
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| 3. |
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| 4. |
- Asaf, Sajjad, et al.
(författare)
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Osmoprotective functions conferred to soybean plants via inoculation with Sphingomonas sp. LK11 and exogenous trehalose
- 2017
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Ingår i: Microbiology Research. - : Elsevier. - 0944-5013 .- 1618-0623. ; 205, s. 135-145
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Tidskriftsartikel (refereegranskat)abstract
- Osmotic stress induced by drought can hinder the growth and yield of crop plants. To understand the eco-physiological role of osmoprotectants, the combined utilization of endophytes and osmolytes (trehalose) can be an ideal strategy used to overcome the adverse effects of drought. Hence, in the present study, we aimed to investigate the role of Sphingomonas sp. LK11, which produces phytohormones and synthesizes trehalose, in improving soybean plant growth under drought-induced osmotic stress (−0.4, −0.9, and −1.2 MPa). The results showed that the inoculation of soybean plants with Sphingomonas sp. LK11 significantly increased plant length, dry biomass, photosynthetic pigments, glutathione, amino acids (proline, glycine, and glutamate), and primary sugars as compared to control plants under varying drought stresses. Trehalose applied to the plant with or without endophyte-inoculation also showed similar plant growth-promoting attributes under stress. Stress exposure significantly enhanced endogenous jasmonic (JA) and abscisic (ABA) acid contents in control plants. In contrast, Sphingomonas sp. LK11-inoculation significantly lowered ABA and JA levels in soybean plants, but these phytohormones increased in response to combined treatments during stress. The drought-induced osmotic stress resistance associated with Sphingomonas sp. LK11 and trehalose was also evidenced by increased mRNA gene expression of soybean dehydration responsive element binding protein (DREB)-type transcription factors (GmDREBa and GmDREB2) and the MYB (myeloblastosis) transcription factor (GmMYBJ1) as compared to the control. In conclusion, our findings demonstrated that inoculation with this endophyte and trehalose improved the negative effects of drought-induced osmotic stress, and it enhanced soybean plant growth and tolerance.
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| 5. |
- Azeem, Muhammad, et al.
(författare)
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Heterobasidion-growth inhibiting Bacillus subtilis A18 exhibits medium- and age-dependent production of lipopeptides
- 2019
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Ingår i: Microbiological Research. - : Elsevier. - 0944-5013 .- 1618-0623. ; 223-225, s. 129-136
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Tidskriftsartikel (refereegranskat)abstract
- Heterobasidion annosum s.s. and H. parviporum are severe pathogens of conifers causing butt rot and root rot thus reducing the economic value of timber. Here, the antifungal activity of Bacillus subtilis isolate A18 against these two Heterobasidion species was investigated. Five different culture media with different culture age were investigated to study the effect of substrate composition and culture age for metabolite production. Bacterial cultures and cell-free culture filtrates were tested for antifungal activity. Inhibition of fungal growth was analysed using the agar disc-diffusion method. MALDI-TOF and LC-HRMS analyses were used to identify the antifungal metabolites. Substrate composition and age of culture were found to be active variables with direct effect on the antifungal activity of bacterial culture extracts. High anti-fungal activity was observed when B. subtilis was cultured in PDB, SGB and LB media for four days. Mass-spectrometry analysis showed the presence of lipopeptides in culture filtrates identified as members of the surfactins, polymixins, kurstakins and fengycins. A culture filtrate containing fengycin-type lipopeptides showed the highest bioactivity against Heterobasidion species. Bacterial cultures had higher bioactivity compared to their respective cell free culture filtrates. The results of the present study suggest that B. subtilis A18 is a powerful biocontrol agent against Heterobasidion infections of tree wounds and stumps.
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| 6. |
- Bahram, Mohammad
(författare)
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Phylogenomics reveals the evolution of root nodulating alpha- and beta-Proteobacteria (rhizobia)
- 2021
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 250
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Tidskriftsartikel (refereegranskat)abstract
- The symbiosis between legumes and nodulating Proteobacteria (so-called rhizobia) contributes greatly to nitrogen fixation in terrestrial ecosystems. Root nodulating Proteobacteria produce nodulation (Nod) factors during the initiation of rhizobial nodule organogenesis on the roots of legumes. Here, we screened the Nod factor production capacity of the previously reported nodule inducing Proteobacteria genera using their genome sequences and assessed the evolutionary history of symbiosis based on phylogenomics. Our analysis revealed 12 genera as potentially Nod factor producing taxa exclusively from alpha- and beta-Proteobacteria. Based on molecular clock analysis, we estimate that rhizobial nitrogen-fixing symbiosis appeared for the first time about 51 Mya (Eocene epoch) in Rhizobiaceae, and it was laterally transferred to multiple symbiotic taxa in alpha- and beta-Proteobacteria. Coevolutionary tests conducted for measuring the phylogenetic congruence between hosts and symbionts revealed only weak topological similarity between legumes and their bacterial symbionts. We conclude that frequent lateral transfer of symbiotic genes, facultative symbiotic nature of rhizobia, differential evolutionary processes of chromosome versus plasmids, and complex multispecies coevolutionary processes have shaped the rhizobia-host associations.
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| 7. |
- Bengtsson, Torbjörn, et al.
(författare)
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Secreted gingipains from P. gingivalis colonies exert potent immunomodulatory effects on human gingival fibroblasts
- 2015
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Ingår i: Microbiological Research. - 0944-5013. ; 178, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Periodontal pathogens, including Porphyromonas gingivalis, can form biofilms in dental pockets and cause inflammation, which is one of the underlying mechanisms involved in the development of periodontal disease, ultimately leading to tooth loss. Although P. gingivalis is protected in the biofilm, it can still cause damage and modulate inflammatory responses from the host, through secretion of microvesicles containing proteinases. The aim of this study was to evaluate the role of cysteine proteinases in P. gingivalis colony growth and development, and subsequent immunomodulatory effects on human gingival fibroblast. By comparing the wild type W50 with its gingipain deficient strains we show that cysteine proteinases are required by P. gingivalis to form morphologically normal colonies. The lysine-specific proteinase (Kgp), but not arginine-specific proteinases (Rgps), was associated with immunomodulation. P. gingivalis with Kgp affected the viability of gingival fibroblasts and modulated host inflammatory responses, including induction of TGF-β1 and suppression of CXCL8 and IL-6 accumulation. These results suggest that secreted products from P. gingivalis, including proteinases, are able to cause damage and significantly modulate the levels of inflammatory mediators, independent of a physical host-bacterial interaction. This study provides new insight of the pathogenesis of P. gingivalis and suggests gingipains as targets for diagnosis and treatment of periodontitis.
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| 8. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Secreted gingipains from Porphyromonas gingivalis colonies exert potent immunomodulatory effects on human gingival fibroblasts
- 2015
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 178, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Periodontal pathogens, including Polphyromonas gingivalis, can form biofilms in dental pockets and cause inflammation, which is one of the underlying mechanisms involved in the development of periodontal disease, ultimately leading to tooth loss. Although P. gingivalis is protected in the biofilm, it can still cause damage and modulate inflammatory responses from the host, through secretion of microvesicles containing proteinases. The aim of this study was to evaluate the role of cysteine proteinases in P. gingivalis colony growth and development, and subsequent immunomodulatory effects on human gingival fibroblast. By comparing the wild type W50 with its gingipain deficient strains we show that cysteine proteinases are required by P. gingivalis to form morphologically normal colonies. The lysine-specific proteinase (Kgp), but not arginine-specific proteinases (Rgps), was associated with immunomodulation. P. gingivalis with Kgp affected the viability of gingival fibroblasts and modulated host inflammatory responses, including induction of TGF-beta 1 and suppression of CXCL8 and IL-6 accumulation. These results suggest that secreted products from P. gingivalis, including proteinases, are able to cause damage and significantly modulate the levels of inflammatory mediators, independent of a physical host-bacterial interaction. This study provides new insight of the pathogenesis of P. gingivalis and suggests gingipains as targets for diagnosis and treatment of periodontitis.
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| 9. |
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| 10. |
- Dalecka, Brigita, et al.
(författare)
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Removal of total phosphorus, ammonia nitrogen and organic carbon from non-sterile municipal wastewater with Trametes versicolor and Aspergillus luchuensis
- 2020
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Ingår i: Microbiological Research. - : Elsevier. - 0944-5013 .- 1618-0623. ; 241:126586, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Discharge of organic load from treated wastewater may cause environmental eutrophication. Recently, fungi have gained much attention due to their removal of pharmaceutical substances by enzymatic degradation and adsorption. However, the fungal effect in removing nutrients is less investigated. Therefore, two fungal species, the white-rot fungus T. versicolor as a laboratory strain and the mold A. luchuensis as an environmental isolate from the municipal wastewater treatment plant, were studied to determine the fungal potential for phosphorus, nitrogen, and the total organic carbon removal from municipal wastewater, carrying out a batch scale experiment to a fluidized bed pelleted bioreactor. During the batch scale experiment, the total removal (99.9 %) of phosphorus by T. versicolor was attained after a 6 hours-long incubation period while the maximal removal efficiency (99.9 %) for phosphorus from A. luchuensis was gained after an incubation period of 24 hours. Furthermore, both fungi showed that the pH adjustment to 5.5 kept the concentration of nitrogen constant and stabilized the total organic carbon reduction process for the entire incubation period. The results from the fluidized bed bioreactor demonstrated opposite tendencies on a nutrient removal comparing to a batch experiment where no significant effect on phosphorus, nitrogen, and total organics carbon reduction was observed. The obtained results from this study of batch and fluidized bed bioreactor experiments are a promising starting point for a successful fungal treatment optimization and application to wastewater treatment.
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| 11. |
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| 12. |
- Fekete, Éva, et al.
(författare)
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Genetic diversity of a Botrytis cinerea cryptic species complex in Hungary
- 2012
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 167:5, s. 283-291
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Tidskriftsartikel (refereegranskat)abstract
- Botrytis cinerea has been described as a species complex containing two cryptic species, referred to as groups I and II. The first B. cinerea group I strains outside of Western Europe were collected in Hungary in 2008 from strawberry and rape plants. Sympatric B. cinerea cryptic species were analyzed using a population genetic approach and phenotypic markers. Statistically significant, but moderate population differentiation was found between the two groups in Hungary. Group I was originally typified by the lack of the transposable elements Boty and Flipper. However, all the Hungarian group I isolates carried the Boty element and one isolate additionally contained Flipper, indicating a much wider genetic variation than previously believed. Vegetative compatibility analyses showed that twelve of the thirteen B. cinerea group I isolates studied belonged to a unique vegetative compatibility group (VCG), but VCGs overlapped between groups. Phenotypic markers such as fenhexamid resistance or asexual spore size were found unsuitable to differentiate between the cryptic species. The results did not confirm the complete separation of the two cryptic species, previously determined with genealogical concordance of the phylogenetic species recognition using multiple gene sequences, and suggest instead the possibility of information exchange between them.
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| 13. |
- Glenting, Jacob, et al.
(författare)
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Anchorless surface associated glycolytic enzymes from Lactobacillus plantarum 299v bind to epithelial cells and extracellular matrix proteins
- 2013
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Ingår i: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 168:5, s. 245-253
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Tidskriftsartikel (refereegranskat)abstract
- An important criterion for the selection of a probiotic bacterial strain is its ability to adhere to the mucosal surface. Adhesion is usually mediated by proteins or other components located on the outer cell surface of the bacterium. In the present study we characterized the adhesive properties of two classical intracellular enzymes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and enolase (ENO) isolated from the outer cell surface of the probiotic bacterium Lactobacillus plantarum 299v. None of the genes encoded signal peptides or cell surface anchoring motifs that could explain their extracellular location on the bacterial surface. The presence of the glycolytic enzymes on the outer surface was verified by western blotting using polyclonal antibodies raised against the specific enzymes. GAPDH and ENO showed a highly specific binding to plasminogen and fibronectin whereas GAPDH but not ENO showed weak binding to mucin. Furthermore, a pH dependent and specific binding of GAPDH and ENO to intestinal epithelial Caco-2 cells at pH 5 but not at pH 7 was demonstrated. The results showed that these glycolytic enzymes could play a role in the adhesion of the probiotic bacterium L. plantarum 299v to the gastrointestinal tract of the host. Finally, a number of probiotic as well non-probiotic Lactobacillus strains were analyzed for the presence of GAPDH and ENO on the outer surface, but no correlation between the extracellular location of these enzymes and the probiotic status of the applied strains was demonstrated. (c) 2013 Elsevier GmbH. All rights reserved.
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| 14. |
- Kardol, Paul
(författare)
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Insights into the seed microbiome and its ecological significance in plant life
- 2023
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, the microbiome has attracted much attention because of the multiple roles and functions that microbes play in plants, animals, and human beings. Seed-associated microbes are of particular interest in being the initial microbial inoculum that affects the critical early life stages of a plant. The seed-microbe interactions are also known to improve nutrient acquisition, resilience against pathogens, and resistance against abiotic stresses. Despite these diverse roles, the seed microbiome has received little attention in plant ecology. Thus, we review the current knowledge on seed microbial diversity, community structure, and functions obtained through culture-dependent and culture-independent approaches. Furthermore, we present a comprehensive synthesis of the ecological literature on seed-microbe interactions to better understand the impact of these interactions on plant health and productivity. We suggest that future research should focus on the role of the seed microbiome in the establishment, colonization and spread of plant species in their native and non-native ranges as it may provide new insights into conservation biology and invasion ecology.
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| 15. |
- Lagunas-Rangel, Francisco Alejandro, et al.
(författare)
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An update on cell division of Giardia duodenalis trophozoites
- 2021
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 250
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Forskningsöversikt (refereegranskat)abstract
- Giardia duodenalis is a flagellated protozoan that is responsible for many cases of diarrheal disease worldwide and is characterized by its great divergence from the model organisms commonly used in studies of basic cellular processes. The life cycle of Giardia involves an infectious cyst form and a proliferative and mobile trophozoite form. Each Giardia trophozoite has two nuclei and a complex microtubule cytoskeleton that consists of eight flagellar axonemes, basal bodies, the adhesive disc, the funis and the median body. Since the success of Giardia infecting other organisms depends on its ability to divide and proliferate efficiently, Giardia must coordinate its cell division to ensure the duplication and partitioning of both nuclei and the multiple cytoskeletal structures. The purpose of this review is to summarize current knowledge about cell division and its regulation in this protist.
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| 16. |
- Lengeler, Klaus B, et al.
(författare)
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Analysis of the cell wall integrity pathway of Ashbya gossypii.
- 2013
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Ingår i: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 168:10, s. 607-614
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Tidskriftsartikel (refereegranskat)abstract
- Fungal cells are exposed to rapidly changing environmental conditions, in particular with regard to the osmotic potential. This requires constant remodeling of the cell wall and, therefore, the cell wall integrity (CWI) MAP-kinase pathway plays a major role in shaping the fungal cell wall to protect from adverse external stresses. To provide a comprehensive functional analysis of the Ashbya gossypii CWI pathway we generated a set of ten deletion mutants in conserved components including the cell surface sensors AgWSC1 and AgMID2, a putative Rho1-guanine nucleotide exchange factor, AgTUS1, the protein kinase C, AgPKC1, the MAP-kinases AgBCK1, AgMKK1 and AgMPK1, and transcription factors known to be involved in CWI signaling AgRLM1, AgSWI4 and AgSWI6. Deletion of AgPKC1 shows a severe growth defect with frequent tip cell lysis. Deletion of components of the MAP-kinase module generates a pronounced colony lysis phenotype in older regions of the mycelium. Cytoplasmic leakage was assayed using alkaline phosphatase and β-galactosidase release assays. This indicated that the lysis phenotypes of CWI pathway mutants may be useful to facilitate the isolation of riboflavin from A. gossypii. Remarkably, the Agwsc1 mutant showed a strong (up to 8-fold) increase of riboflavin in the growth medium compared to the parental strain.
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| 17. |
- Marcotte, Harold, et al.
(författare)
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Characterization and complete genome sequences of L. rhamnosus DSM 14870 and L-gasseri DSM 14869 contained in the EcoVag (R) probiotic vaginal capsules
- 2017
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Ingår i: Microbiological Research. - : ELSEVIER GMBH, URBAN & FISCHER VERLAG. - 0944-5013 .- 1618-0623. ; 205, s. 88-98
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus rhamnosus DSM 14870 and Lactobacillus gasseri DSM 14869 were previously isolated from the vaginal epithelial cells (VEC) of healthy women and selected for the development of the vaginal EcoVag (R) probiotic capsules. EcoVag (R) was subsequently shown to provide long-term cure and reduce relapse of bacterial vaginosis (BV) as an adjunct to antibiotic therapy. To identify genes potentially involved in probiotic activity, we performed genome sequencing and characterization of the two strains. The complete genome analysis of both strains revealed the presence of genes encoding functions related to adhesion, exopolysaccharide (EPS) biosynthesis, antimicrobial activity, and CRISPR adaptive immunity but absence of antibiotic resistance genes. Interesting features of L. rhamnosus DSM 14870 genome include the presence of the spaCBA-srtC gene encoding spaCBA pill and interruption of the gene cluster encoding long galactose-rich EPS by integrases. Unique to L. gasseri DSM 14869 genome was the presence of a gene encoding a putative (1456 amino acid) new adhesin containing two rib/alpha-like repeats. L. rhamnosus DSM 14870 and L. gasseri DSM 14869 showed acidification of the culture medium (to pH 3.8) and a strong adhesion capability to the Caco-2 cell line and VEC. L gasseri DSM 14869 could produce a thick (40 nor) EPS layer and hydrogen peroxide. L. rhamnosus DSM 14870 was shown to produce SpaCBA pili and a 20 nor EPS layer, and could inhibit the growth of Gardnerella vaginalis, a bacterium commonly associated with BV. The genome sequences provide a basis for further elucidation of the molecular basis for their probiotic functions.
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| 18. |
- Shanthakumar, S P, et al.
(författare)
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Broad spectrum antimicrobial compounds from the bacterium Exiguobacterium mexicanum MSSRFS9.
- 2015
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Ingår i: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 178, s. 59-65
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Tidskriftsartikel (refereegranskat)abstract
- Clinical bacterial pathogens front a major challenge for the clinical researchers and physicians. In particular microbial pathogens like Escherichia coli, Shigella flexneri, Klebsiella pneumonia and Salmonella enterica are apparelled with systemic machineries to bring down the human immune system as well as proliferate dramatically in a short period which in turn cause a pronounced ailment to the human health. In vitro evaluation of four purified compounds isolated from rhizosphere bacterium Exiguobacterium mexicanum tested against clinical pathogens mentioned above by disc diffusion method showed the two compounds viz., 3,6,18-trione, 9,10-dihydro-12'-hydroxyl-2methyl-5-(phenyl methyl) (5'-alpha, 10-alpha)-dihydroergotamine (C3) and dipropyl - S-propyl ester (C4) exhibit antibacterial property against all the tested pathogens. Among the four clinical pathogens tested, compound C3 has shown higher zone of inhibition against S. enterica with 17±0mm, followed by S. flexneri with 16.5±0.7mm, E. coli with 15±0mm and K. pneumoniae with 14±0mm, respectively. The compound C4 has shown higher antimicrobial activity against S. enterica with 21.5±0.7mm zone of inhibition, followed by S. flexneri with 19.5±0.7mm, E. coli with 17±0mm and K. pneumoniae with 16±0mm, these two compounds were found to be safer when subjected to rat haematological and enzymatic analysis.
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| 19. |
- Sjöling, Åsa, 1968, et al.
(författare)
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Detection of major diarrheagenic bacterial pathogens by multiplex PCR panels
- 2015
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 172, s. 34-40
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Tidskriftsartikel (refereegranskat)abstract
- Diarrheal diseases remain a major threat to the youngest population in low- and middle-income countries. The main bacterial pathogens causing diarrhea are diarrheagenic Escherichia coli (DEC) that consists of enteroaggregative (EAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enterohemorrhagic EHEC and enteroinvasive E. coli (EIEC), Salmonella, Shigella spp. (S. dysenteria, S. sonnei, S. flexneri) Campylobacter (C. coli, C. jejuni), Vibrio (V. vulnificus, V. parahaemolyticusm, V. cholerae), Yersinia enterocolitica and Aeromonas hydrophila. The aim of this study was to set up rapid multiplex PCR (mPCR) panels to identify these diarrheagenic pathogens based on their specific virulence genes. Primers against specific target genes were combined into three mPCR panels: one for diarrheal E. coli, one for pathogens causing mainly bloody diarrhea, and the third for the remaining pathogens. The panels were tested against a set of stool samples from Swedish children with diarrhea and controls and the analysis identified bacterial pathogens in 14/54 (26%) of the samples. These results show that our three developed mPCR panels can detect main bacterial diarrheagenic pathogens in clinical samples.
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| 20. |
- Szabó, Attila
(författare)
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The effect of seed bacterization with Bacillus paralicheniformis 2R5 on bacterial and fungal communities in the canola rhizosphere
- 2023
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Ingår i: Microbiological Research. - 0944-5013 .- 1618-0623. ; 275
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Tidskriftsartikel (refereegranskat)abstract
- Bacillus sp. is one of the best-studied plant growth-promoting rhizobacteria (PGPR). However, more detailed studies targeting its effect on the rhizosphere microbial community are required for improving management practices regarding its commercial application in the field. Our earlier study showed that PGPR Bacillus paralicheniformis 2R5 stimulated canola growth. Hence, this study aimed to assess the time-course impact of B. paralicheniformis 2R5 on bacterial and fungal community structure and diversity. The results showed that inoculation with B. paralicheniformis 2R5 initially significantly decreased the observed bacterial richness compared to the control, while after 44 days of treatment this alpha diversity metrics increased. A linear discriminant analysis effect size showed that B. paralicheniformis 2R5 altered the soil bacterial and fungal community structure by increasing the abundance of plants' beneficial microorganisms such as Nitrospira, Ramlibacter, Sphingomonas, Massilia, Terrimonas as well as Solicoccozyma, Schizothecium, Cyphellophora, Fusicolla, Humicola. B. paralicheniformis 2R5 seems to be a promising alternative to chemical pesticides and can be considered for practical application in the field. Its ability to alter the rhizosphere microbiome by increasing the diversity and composition of bacterial communities and increasing plants' beneficial groups of fungi, appears to be important in terms of improving canola development. However, further studies on these increased microbial taxa are necessary to confirm their function in promoting canola growth.
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| 21. |
- Tadesse, Belay Tilahun, et al.
(författare)
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Bad to the bone? – Genomic analysis of Enterococcus isolates from diverse environments reveals that most are safe and display potential as food fermentation microorganisms
- 2024
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Ingår i: Microbiological Research. - 0944-5013. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- Enterococci comprise a group of lactic acid bacteria (LAB) with considerable potential to serve as food fermentation microorganisms. Unfortunately, enterococci have received a lot of negative attention, due to the occurrence of pathogenic and multidrug resistant strains. In this study, we used genomics to select safe candidates among the forty-four studied enterococcal isolates. The genomes of the forty-four strains were fully sequenced and assessed for presence of virulence and antibiotic resistance genes. Nineteen isolates belonging to the species Enterococcus lactis, Enterococcus faecium, Enterococcus durans, and Enterococcus thailandicus, were deemed safe from the genome analysis. The presence of secondary metabolite gene clusters for bacteriocins was assessed, and twelve candidates were found to secrete antimicrobial compounds effective against Listeria monocytogenes isolated from cheese and Staphylococcus aureus. Physiological characterization revealed nineteen industrial potentials; all strains grew well at 42 °C and acidified 1.5 hours faster than their mesophilic counterpart Lactococcus lactis, with which they share metabolism and flavor forming ability. We conclude that a large fraction of the examined enterococci were safe and could serve as excellent food fermentation microorganisms with inherent bioprotective abilities.
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| 22. |
- Thaduri, Srinivas, et al.
(författare)
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Gut microbiota assembly of Gotland varroa-surviving honey bees excludes major viral pathogens
- 2023
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Ingår i: Microbiological Research. - 0944-5013 .- 1618-0623. ; 274
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Tidskriftsartikel (refereegranskat)abstract
- The spread of the parasite Varroa destructor and associated viruses has resulted in massive honey bee colony losses with considerable economic and ecological impact. The gut microbiota has a major role in shaping honey bees tolerance and resistance to parasite infestation and viral infection, but the contribution of viruses to the assembly of the host microbiota in the context of varroa resistance and susceptibility remains unclear. Here, we used a network approach including viral and bacterial nodes to characterize the impact of five viruses, Apis Rhabdovirus-1 (ARV-1), Black Queen Cell virus (BQCV), Lake Sinai virus (LSV), Sacbrood virus (SBV) and Deformed wing virus (DWV) on the gut microbiota assembly of varroa-susceptible and Gotland varroa-surviving honey bees. We found that microbiota assembly was different in varroa-surviving and varroa-susceptible honey bees with the network of the latter having a whole module not present in the network of the former. Four viruses, ARV-1, BQCV, LSV, and SBV, were tightly associated with bacterial nodes of the core microbiota of varroasusceptible honey bees, while only two viruses BQCV and LSV, appeared correlated with bacterial nodes in varroa-surviving honey bees. In silico removal of viral nodes caused major re-arrangement of microbial networks with changes in nodes centrality and significant reduction of the networks' robustness in varroa-susceptible, but not in varroa-surviving honey bees. Comparison of predicted functional pathways in bacterial communities using PICRUSt2 showed the superpathway for heme b biosynthesis from uroporphyrinogen-III and a pathway for arginine, proline, and ornithine interconversion as significantly increased in varroa-surviving honey bees. Notably, heme and its reduction products biliverdin and bilirubin have been reported as antiviral agents. These findings show that viral pathogens are differentially nested in the bacterial communities of varroa-surviving and varroa-susceptible honey bees. These results suggest that Gotland honey bees are associated with minimallyassembled and reduced bacterial communities that exclude viral pathogens and are resilient to viral nodes removal, which, together with the production of antiviral compounds, may explain the resiliency of Gotland honey bees to viral infections. In contrast, the intertwined virus-bacterium interactions in varroa-susceptible networks suggest that the complex assembly of microbial communities in this honey bee strain favor viral infections, which may explain viral persistence in this honey bee strain. Further understanding of protective mechanisms mediated by the microbiota could help developing novel ways to control devastating viral infections affecting honey bees worldwide.
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| 23. |
- Tobias, Joshua, 1969, et al.
(författare)
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Simple and rapid multiplex PCR for identification of the main human diarrheagenic Escherichia coli
- 2012
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013. ; 167:9, s. 564-570
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Tidskriftsartikel (refereegranskat)abstract
- Establishment of a simple and rapid multiplex PCR system for identification of the main diarrheagenic E. coli categories, including enteroaggregative E. coil. enterotoxigenic E. coil, enteropathogenic E. coil, and enterohemorrhagic E. coil, is described. This two-step multiplex PCR system allows the identification by targeting CVD432, LT, STh, Sip, Eae, Bfp, Stx1, and Stx2. By applying the developed multiplex PCR system, categorization of E. coil isolates isolated from stool samples of infants with diarrhea into the main diarrheagenic E. coil categories is also shown. (C) 2011 Elsevier GmbH. All rights reserved.
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| 24. |
- Tzelepis, Georgios
(författare)
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Insights into the multitrophic interactions between the biocontrol agent Bacillus subtilis MBI 600, the pathogen Botrytis cinerea and their plant host
- 2021
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 248
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Tidskriftsartikel (refereegranskat)abstract
- Botrytis cinerea is a plant pathogen causing the gray mold disease in a plethora of host plants. The control of the disease is based mostly on chemical pesticides, which are responsible for environmental pollution, while they also pose risks for human health. Furthermore, B. cinerea resistant isolates have been identified against many fungicide groups, making the control of this disease challenging. The application of biocontrol agents can be a possible solution, but requires deep understanding of the molecular mechanisms in order to be effective. In this study, we investigated the multitrophic interactions between the biocontrol agent Bacillus subtilis MBI 600, a new commercialized biopesticide, the pathogen B. cinerea and their plant host. Our analysis showed that this biocontrol agent reduced B. cinerea mycelial growth in vitro, and was able to suppress the disease incidence on cucumber plants. Moreover, treatment with B. subtilis led to induction of genes involved in plant immunity. RNAseq analysis of B. cinerea transcriptome upon exposure to bacterial secretome, showed that genes coding for MFS and ABC transporters were highly induced. Deletion of the Bcmfs1 MFS transporter gene, using a CRISP/Cas9 editing method, affected its virulence and the tolerance of B. cinerea to bacterial secondary metabolites. These findings suggest that specific detoxification transporters are involved in these interactions, with crucial role in different aspects of B. cinerea physiology.
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