| 1. |
- Glenting, Jacob, et al.
(author)
-
Anchorless surface associated glycolytic enzymes from Lactobacillus plantarum 299v bind to epithelial cells and extracellular matrix proteins
- 2013
-
In: Microbiological Research. - : Elsevier BV. - 1618-0623 .- 0944-5013. ; 168:5, s. 245-253
-
Journal article (peer-reviewed)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.
|
|
| 2. |
- Bednarska, Olga, et al.
(author)
-
A postbiotic fermented oat gruel may have a beneficial effect on the colonic mucosal barrier in patients with irritable bowel syndrome
- 2022
-
In: Frontiers in Nutrition. - : FRONTIERS MEDIA SA. - 2296-861X. ; 9
-
Journal article (peer-reviewed)abstract
- Background: Impaired intestinal permeability and microbial dysbiosis are important pathophysiological mechanisms underlying irritable bowel syndrome (IBS). ReFerm (R)( ), also called Profermin (R), is a postbiotic product of oat gruel fermented with Lactobacillus plantarum 299v. In this study, we investigated whether ReFerm (R) has a beneficial effect on the intestinal epithelial barrier function in patients with IBS.Materials and methods: Thirty patients with moderate to severe IBS-diarrhoea (IBS-D) or IBS-mixed (IBS-M) were treated with enema containing ReFerm (R) or placebo. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment with ReFerm (R) or placebo twice daily. The biopsies were mounted in Ussing chambers, and paracellular and transcellular permeabilities were measured for 120 min. In addition, the effects of ReFerm (R) or placebo on the epithelial barrier were investigated in vitro using Caco-2 cells.Results: ReFerm (R) reduced paracellular permeability (p < 0.05) and increased transepithelial resistance (TER) over time (p < 0.01), whereas the placebo had no significant effect in patients. In ReFerm (R)-treated Caco-2 cells, paracellular and transcellular permeabilities were decreased compared to the control (p < 0.05) and placebo (p < 0.01). TER was increased in Caco-2 ReFerm (R)-treated cells, and normalised TER was increased in ReFerm (R)-treated Caco-2 cells compared to control (p < 0.05) and placebo-treated (p < 0.05) cells.Conclusion: ReFerm (R) significantly reduced paracellular permeability and improved TER in colonic biopsies collected from patients with IBS and in a Caco-2 cell model. Our results offer new insights into the potential benefits of ReFerm (R) in IBS management. Further studies are needed to identify the molecular mechanisms underlying the barrier-protective properties of ReFerm (R).
|
|
| 3. |
- Holst, Bjørn, et al.
(author)
-
Molecular switch controlling expression of the mannose-specific adhesin, Msa, in Lactobacillus plantarum
- 2019
-
In: Applied and Environmental Microbiology. - 0099-2240. ; 85:10
-
Journal article (peer-reviewed)abstract
- Some lactic acid bacteria, especially Lactobacillus spp., possess adhesive properties enabling colonization of the human gastrointestinal tract. Two probiotic Lactobacillus plantarum strains, WCSF1 and 299v, display highly different mannose-specific adhesion, with L. plantarum 299v being superior to L. plantarum WCFS1 based on a yeast agglutination assay. A straightforward correlation between the mannose adhesion capacity and domain composition of the mannose-specific adhesin (Msa) in the two strains has not been demonstrated previously. In this study, we analyzed the promoter regions upstream of the msa gene encoding a mannose-specific adhesin in these two strains. The promoter region was mapped by primer extension and DNA sequence analysis, and only a single nucleotide change was identified between the two strains. However, Northern blot analysis showed a stronger msa transcript band in 299v than in WCFS1 correlating with the different adhesion capacities. During the establishment of a high-throughput yeast agglutination assay, we isolated variants of WCFS1 that displayed a very strong mannose-specific adhesion phenotype. The region upstream of the msa gene in these variants showed an inversion of a 104-bp fragment located between two perfectly inverted repeats present in the untranslated leader region. The inversion disrupts a strong hairpin structure that otherwise most likely would terminate the msa transcript. In addition, the ribosome binding site upstream of the msa gene, which is also masked within this hairpin structure, becomes accessible upon inversion, thereby increasing the frequency of translation initiation in the variant strains. Furthermore, Northern blot analysis showed a higher abundance of the msa transcript in the variants than in the wild type, correlating with a strong-Msa phenotype.
|
|
| 4. |
- Napier, Bruce, et al.
(author)
-
Ultra-broadband infrared gas sensor for pollution detection : the TRIAGE project
- 2021
-
In: Journal of Physics; Photonics. - : IOP Publishing Ltd. - 2515-7647. ; 3:3
-
Journal article (other academic/artistic)abstract
- Air pollution is one of the largest risk factors for disease or premature death globally, yet current portable monitoring technology cannot provide adequate protection at a local community level. Within the TRIAGE project, a smart, compact and cost-effective air quality sensor network will be developed for the hyperspectral detection of gases which are relevant for atmospheric pollution monitoring or dangerous for human health. The sensor is based on a mid-infrared supercontinuum source, providing ultra-bright emission across the 2-10 mu m wavelength region. Within this spectral range, harmful gaseous species can be detected with high sensitivity and selectivity. The spectroscopic sensor, which includes a novel multi-pass cell and detector, enables a smart robust photonic sensing system for real-time detection. With built-in chemometric analysis and cloud connection, the sensor will feed advanced deep-learning algorithms for various analyses, ranging from long-term continental trends in air pollution to urgent local warnings and alerts. Community-based distributed pollution sensing tests will be verified on municipal building rooftops and local transport platforms.
|
|
