Activation of H+-ATPase of the Plasma Membrane of Saccharomyces cerevisiae by Glucose: The Role of Sphingolipid and Lateral Enzyme Mobility

Activation of the plasma membrane H+-ATPase of the yeast Saccharomyces cerevisiae by glucose is a complex process that has not yet been completely elucidated. This study aimed to shed light on the role of lipids and the lateral mobility of the enzyme complex during its activation by glucose. The significance of H+-ATPase oligomerization for the activation of H+-ATPase by glucose was shown using the strains lcb1-100 and erg6, with the disturbed synthesis of sphyngolipid and ergosterol, respectively. Experiments with GFP-fused H+-ATPase showed a decrease in fluorescence anisotropy during the course of glucose activation, suggesting structural reorganization of the molecular domains. An immunogold assay showed that the incubation with glucose results in the spatial redistribution of ATPase complexes in the plasma membrane. The data suggest that (1) to be activated by glucose, H+-ATPase is supposed to be in an oligomeric state, and (2) glucose activation is accompanied by the spatial movements of H+-ATPase clusters in the PM

'Limosilactobacillus fermentum' Strain 3872 : antibacterial and immunoregulatory properties and synergy with prebiotics against socially significant antibiotic-resistant infections of animals and humans

Limosilactobacillus fermentum strain 3872 (LF3872) was originally isolated from the breast milk of a healthy woman during lactation and the breastfeeding of a child. The high-quality genome sequencing of LF3872 was performed, and a gene encoding a unique bacteriocin was discovered. It was established that the bacteriocin produced by LF3872 (BLF3872) belongs to the family of cell-wall-degrading proteins that cause cell lysis. The antibacterial properties of LF3872 were studied using test cultures of antibiotic-resistant Gram-positive and Gram-negative pathogens. Gram-positive pathogens (Staphylococcus aureus strain 8325-4 and S. aureus strain IIE CI-SA 1246) were highly sensitive to the bacteriolytic action of LF3872. Gram-negative pathogens (Escherichia coli, Salmonella strains, and Campylobacter jejuni strains) were more resistant to the bacteriolytic action of LF3872 compared to Gram-positive pathogens. LF3872 is a strong co-aggregator of Gram-negative pathogens. The cell-free culture supernatant of LF3872 (CSLF3872) induced cell damage in the Gram-positive and Gram-negative test cultures and ATP leakage. In the in vitro experiments, it was found that LF3872 and Actigen prebiotic (Alltech Inc., Nicholasville, KY, USA) exhibited synergistic anti-adhesive activity against Gram-negative pathogens. LF3872 has immunoregulatory properties: it inhibited the lipopolysaccharide-induced production of proinflammatory cytokines IL-8, IL-1β, and TNF-α in a monolayer of Caco-2 cells; inhibited the production of IL-12 and stimulated the production of IL-10 in immature human dendritic cells; and stimulated the production of TGF-β, IFN-γ, and IgA in the immunocompetent cells of intestinal Peyer’s patches (PPs) in mice. These results indicate the possibility of creating a synbiotic based on LF3872 and a prebiotic derived from Saccharomyces cerevisiae cell wall components. Such innovative drugs and biologically active additives are necessary for the implementation of a strategy to reduce the spread of antibiotic-resistant strains of socially significant animal and human infections

Fluorescence depolarization (anisotropy) <b>r</b> of PMA1-GFP in whole cells after 15 min incubation with 100 mM glucose or deoxyglucose.

<p>Fluorescence depolarization (anisotropy) <b>r</b> of PMA1-GFP in whole cells after 15 min incubation with 100 mM glucose or deoxyglucose.</p

Pma1 activity in situ (nmol P_i/min/mg total cell protein, <i>n</i> = 3±SD) after 15-min incubation of <i>S. cerevisiae</i> whole cells with 100 mM glucose or 100 mM deoxyglucose. The change of activity in % of initial activity is given in parenthesis.

<p>Pma1 activity in situ (nmol P_i/min/mg total cell protein, <i>n</i> = 3±SD) after 15-min incubation of <i>S. cerevisiae</i> whole cells with 100 mM glucose or 100 mM deoxyglucose. The change of activity in % of initial activity is given in parenthesis.</p

Soil bacteria as a basis for sustainable development of the environment

Soil is an inexhaustible source of microorganisms of significant interest to biotechnology. Bacteria are able to control the growth of pathogenic microflora, stimulate plant growth, and decompose pollutants of varying degrees of toxicity. Bacteria make a significant contribution to the cycle of substances. The aim of this work was to isolate aerobic microorganisms from soil samples of two types - forest, without technogenic history, and agro-industrial, and to evaluate their properties. 15 strains of bacteria were isolated from forest soil, of which representatives of the genera Rhodococcus, Bacillus, Arthrobacter, Paenibacillus, Pseudomonas, Acinetobacter were able to degrade such persistent pollutants as chlorophenols, biphenyl and naphthalene. 77 strains were isolated from chernozem, of which 15 used benzoate as the sole source of carbon and energy. Thus, it has been shown that bacterial strains isolated from both forest and agricultural soil have a certain biodegradative activity, which allows them to reduce the level of pollution

Yeast strains used in this study.

<p>Yeast strains used in this study.</p

Immunogold labeling of Pma1 in the plasma membrane of <i>S. cerevisiae erg6</i> and <i>lcb1-100</i>.

<p>(A) – glucose-starved cells of the <i>erg6</i> strain, Pma1 was distributed in the membrane as single structures; (B) – <i>erg6</i> cells that had metabolized glucose for 15 min, Pma1 formed complexes; (C) - glucose-starved cells of the <i>lcb1-100</i> strain, Pma1 was distributed in the membrane as single structures; (D) – <i>lcb1-100</i> cells that had metabolized glucose for 15 min, Pma1 was distributed in the membrane as single structures. CW = cell wall; PM = plasma membrane.</p

Immunogold labeling of Pma1 in the plasma membrane of <i>S. cerevisiae SEY6210</i>.

<p>(A) – glucose-starved cells, Pma1 was distributed in the membrane as single structures; (B) – cells that had metabolized glucose for 15 min, Pma1 formed large bunch-like complexes; (C) – enlarged fragment of photograph (B) CW = cell wall; PM = plasma membrane.</p

Characterization of Soil Bacteria with Potential to Degrade Benzoate and Antagonistic to Fungal and Bacterial Phytopathogens

The intensive development of agriculture leads to the depletion of land and a decrease in crop yields and in plant resistances to diseases. A large number of fertilizers and pesticides are currently used to solve these problems. Chemicals can enter the soil and penetrate into the groundwater and agricultural plants. Therefore, the primary task is to intensify agricultural production without causing additional damage to the environment. This problem can be partially solved using microorganisms with target properties. Microorganisms that combine several useful traits are especially valuable. The aim of this work was to search for new microbial strains, which are characterized by the ability to increase the bioavailability of nutrients, phytostimulation, the antifungal effect and the decomposition of some xenobiotics. A few isolated strains of the genera Bacillus and Pseudomonas were characterized by high activity against fungal phytopathogens. One of the bacterial strains identified as Priestiaaryabhattai on the basis of the 16S rRNA gene sequence was characterized by an unusual cellular morphology and development cycle, significantly different from all previously described bacteria of this genus. All isolated bacteria are capable of benzoate degradation as a sign of the ability to degrade aromatic compounds. Isolated strains were shown to be prospective agents in biotechnologies

From Rest to Growth: Life Collisions of Gordonia polyisoprenivorans 135

In the process of evolution, living organisms develop mechanisms for population preservation to survive in unfavorable conditions. Spores and cysts are the most obvious examples of dormant forms in microorganisms. Non-spore-forming bacteria are also capable of surviving in unfavorable conditions, but the patterns of their behavior and adaptive reactions have been studied in less detail compared to spore-forming organisms. The purpose of this work was to study the features of transition from dormancy to active vegetative growth in one of the non-spore-forming bacteria, Gordonia polisoprenivorans 135, which is known as a destructor of such aromatic compounds as benzoate, 3-chlorobenzoate, and phenol. It was shown that G. polyisoprenivorans 135 under unfavorable conditions forms cyst-like cells with increased thermal resistance. Storage for two years does not lead to complete cell death. When the cells were transferred to fresh nutrient medium, visible growth was observed after 3 h. Immobilized cells stored at 4 &deg;C for at least 10 months regenerated their metabolic activity after only 30 min of aeration. A study of the ultrathin organization of resting cells by transmission electron microscopy combined with X-ray microanalysis revealed intracytoplasmic electron-dense spherical membrane ultrastructures with significant similarity to previously described acidocalcisomas. The ability of some resting G. polyisoprenivorans 135 cells in the population to secrete acidocalcisome-like ultrastructures into the extracellular space was also detected. These structures contain predominantly calcium (Ca) and, to a lesser extent, phosphorus (P), and are likely to serve as depots of vital macronutrients to maintain cell viability during resting and provide a quick transition to a metabolically active state under favorable conditions. The study revealed the features of transitions from active growth to dormant state and vice versa of non-spore-forming bacteria G. polyisoprenivorans 135 and the possibility to use them as the basis of biopreparations with a long shelf life