scholarly journals Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia

2021 ◽  
Vol 22 (21) ◽  
pp. 11925
Author(s):  
Lena Schleicher ◽  
Sebastian Herdan ◽  
Günter Fritz ◽  
Andrej Trautmann ◽  
Jana Seifert ◽  
...  
Keyword(s):  
Central Carbon Metabolism ◽  
Gardnerella Vaginalis ◽  
Nadh:Quinone Oxidoreductase ◽  
Highly Active ◽  
Prevotella Bivia ◽  
Transmembrane Voltage ◽  
Activity Measurements ◽  
Membrane Bound ◽  
The Impact ◽  
Membrane Bound Enzymes

Replacement of the Lactobacillus dominated vaginal microbiome by a mixed bacterial population including Prevotella bivia is associated with bacterial vaginosis (BV). To understand the impact of P. bivia on this microbiome, its growth requirements and mode of energy production were studied. Anoxic growth with glucose depended on CO2 and resulted in succinate formation, indicating phosphoenolpyruvate carboxylation and fumarate reduction as critical steps. The reductive branch of fermentation relied on two highly active, membrane-bound enzymes, namely the quinol:fumarate reductase (QFR) and Na+-translocating NADH:quinone oxidoreductase (NQR). Both enzymes were characterized by activity measurements, in-gel fluorography, and VIS difference spectroscopy, and the Na+-dependent build-up of a transmembrane voltage was demonstrated. NQR is a potential drug target for BV treatment since it is neither found in humans nor in Lactobacillus. In P. bivia, the highly active enzymes L-asparaginase and aspartate ammonia lyase catalyze the conversion of asparagine to the electron acceptor fumarate. However, the by-product ammonium is highly toxic. It has been proposed that P. bivia depends on ammonium-utilizing Gardnerella vaginalis, another typical pathogen associated with BV, and provides key nutrients to it. The product pattern of P. bivia growing on glucose in the presence of mixed amino acids substantiates this notion.

scholarly journals Atopobium vaginae and Prevotella bivia Are Able to Incorporate and Influence Gene Expression in a Pre-Formed Gardnerella vaginalis Biofilm

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 247
Author(s):  
Joana Castro ◽  
Aliona S. Rosca ◽  
Christina A. Muzny ◽  
Nuno Cerca
Keyword(s):  
Virulence Genes ◽  
Gardnerella Vaginalis ◽  
Bacterial Populations ◽  
Biofilm Model ◽  
Prevotella Bivia ◽  
The Impact ◽  
Influence Gene Expression ◽  
Pna Fish ◽  
Atopobium Vaginae

Bacterial vaginosis (BV) is associated with a highly structured polymicrobial biofilm on the vaginal epithelium where Gardnerella species presumably play a pivotal role. Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia are vaginal pathogens detected during the early stages of incident BV. Herein, we aimed to analyze the impact of A. vaginae and P. bivia on a pre-established G. vaginalis biofilm using a novel in vitro triple-species biofilm model. Total biofilm biomass was determined by the crystal violet method. We also discriminated the bacterial populations in the biofilm and in its planktonic fraction by using PNA FISH. We further analyzed the influence of A. vaginae and P. bivia on the expression of key virulence genes of G. vaginalis by quantitative PCR. In our tested conditions, A. vaginae and P. bivia were able to incorporate into pre-established G. vaginalis biofilms but did not induce an increase in total biofilm biomass, when compared with 48-h G. vaginalis biofilms. However, they were able to significantly influence the expression of HMPREF0424_0821, a gene suggested to be associated with biofilm maintenance in G. vaginalis. This study suggests that microbial relationships between co-infecting bacteria can deeply affect the G. vaginalis biofilm, a crucial marker of BV.

Some Aspects of the Polyhexamethyleneguanidine Salts Effect on Cell Cultures

2014 ◽  
Vol 1 (1) ◽  
pp. 62-67 ◽  
Author(s):  
M. Mandygra ◽  
A. Lysytsia
Keyword(s):  
Proliferative Activity ◽  
Cell Monolayer ◽  
Eukaryotic Cell ◽  
Culture Methods ◽  
Cellular Processes ◽  
Negative Effect ◽  
Membrane Bound ◽  
Membrane Bound Enzymes ◽  
Anion Type ◽  
Cell Culture Methods

Aim. To investigate the effect of polyhexamethyleneguanidine (PHMG) to eukaryotic cell culture. Methods. The passaged bovine tracheal cells culture (TCC) and primary culture of chicken embryo fi broblasts (FCE) were used in the experiments. TCC and FCE monolayers were treated with aqueous solutions of PHMG chloride or succinate. The method of PHMG polycation adsorption to the cells’ plasma membrane together with microscopy were applied. Results. The dependence of PHMG effect on the eukaryotic cells on the agent concentration, duration of exposure and the anion type has been fi xed. The PHMG concentration of 10 –5 per cent (0.1 μg/ml) never causes degradation of the previously formed cell monolayer, while the higher concentrations damage it. The conditions of the PHMG chloride and succinate’s negative effect on cell proliferation and inhibition of monolayer formation were determined. The hypothesis that under certain conditions PHMG stimulates the proliferative activity of the cells has been confi rmed. Stimulation may be associated with non-specifi c stress adaptation of cells. In this case, it is due to modifi cations of the cell membrane after PHMG adsorption to it. Conclusions. PHMG polycation binds with the membrane’s phosphoglycerides fi rmly and irreversibly. A portion of the lipids are removed from participation in the normal cellular processes at that. At the same time, the synthesis of new lipids and membrane-bound enzymes is probably accelerated. The phospholip ids’ neogenesis acceleration can stimulate mitosis under certain conditions. The obtained results can be used in the biotechnologies.

scholarly journals Regulation of membrane-bound enzymes of glycosphingolipid biosynthesis

1984 ◽  
Vol 25 (13) ◽  
pp. 1541-1547
Author(s):  
J D Burczak ◽  
R M Soltysiak ◽  
C C Sweeley
Keyword(s):  
Membrane Bound ◽  
Membrane Bound Enzymes ◽  
Glycosphingolipid Biosynthesis

scholarly journals The Profound Influence of Lipid Composition on the Catalysis of the Drug Target NADH Type II Oxidoreductase

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 363
Author(s):  
Albert Godoy-Hernandez ◽  
Duncan G. G. McMillan
Keyword(s):  
Acyl Chain ◽  
Cellular Respiration ◽  
Type Ii ◽  
Nadh:Quinone Oxidoreductase ◽  
Chain Composition ◽  
Membrane Bound ◽  
Lipid Environment ◽  
Lipid Specificity ◽  
Mediated Catalysis ◽  
Quinone Pool

Lipids play a pivotal role in cellular respiration, providing the natural environment in which an oxidoreductase interacts with the quinone pool. To date, it is generally accepted that negatively charged lipids play a major role in the activity of quinone oxidoreductases. By changing lipid compositions when assaying a type II NADH:quinone oxidoreductase, we demonstrate that phosphatidylethanolamine has an essential role in substrate binding and catalysis. We also reveal the importance of acyl chain composition, specifically c14:0, on membrane-bound quinone-mediated catalysis. This demonstrates that oxidoreductase lipid specificity is more diverse than originally thought and that the lipid environment plays an important role in the physiological catalysis of membrane-bound oxidoreductases.

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