scholarly journals BIOFILM FORMING ACTIVITY OF NON-FERMENTING GRAM-NEGATIVE BACTERIA

2021 ◽  
Vol 74 (2) ◽  
pp. 252-256
Author(s):  
Valentyn P. Kovalchuk ◽  
Oleksandr A. Nazarchuk ◽  
Vita M. Burkot ◽  
Nadiia S. Fomina ◽  
Zoіa M. Prokopchuk ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Biofilm Formation ◽  
Physical Factors ◽  
Gram Negative Bacteria ◽  
Sterile Water ◽  
Standard Medium ◽  
Nutrient Media ◽  
The Media ◽  
High Concentrations ◽  
Adverse Environmental Conditions

The aim: To study the influence of chemical, physical factors on the biofilm forming activity of P. aeruginosa, A. baumannii. Materials and methods: Biofilm forming activity of P. aeruginosa (10 isolates) and A. baumannii (10 isolates) was studied in nutrient media of different composition. There was used the method in 96-well crystalline violet staining plates with spectrophotometry (STAT FAX®4300, wavelength of 620 nm). Results: Results showed that in standard medium (trypto-soy broth), strains of P. aeruginosa (90%) and A. baumannii (60%) obtained high biofilm forming activity. A. baumannii formed biofilms even in sterile water. Biofilm forming activity of urease positive P. aeruginosa increased in the medium with 1.0% urea. Both Acinetbacteria and Pseudomonas intensively produced their biofilms in the presence of 5% serum or sub-bacteriostatic concentrations of levofloxacin in the media. High concentrations of sodium chloride inhibited their biofilm activity. Conclusions: Isolates of Acinetobacter and Pseudomonas obtain the protective biofilm-forming ability under such adverse environmental conditions as insufficient nutrients, high osmotic pressure, the presence of antibiotics but at high concentrations sodium chloride biofilm-formation is stimulated only in the first bacteria and suppressed in the second one.

ABOLITION OF MAGNESIUM-INDUCED HYPOCALCAEMIA BY ACUTE THYRO-PARATHYROIDECTOMY IN THE CAT

1970 ◽  
Vol 64 (1) ◽  
pp. 150-158 ◽  
Author(s):  
S. Pors Nielsen
Keyword(s):  
Sodium Chloride ◽  
Flow Rate ◽  
Magnesium Chloride ◽  
Calcium Concentration ◽  
Plasma Calcium ◽  
Magnesium Concentration ◽  
Isotonic Sodium Chloride ◽  
Plasma Calcium Concentration ◽  
High Concentrations ◽  
Plasma Magnesium

ABSTRACT Intravenous infusion of isotonic magnesium chloride into young cats with a resultant mean plasma magnesium concentration of 7.7 meq./100 g protein was followed by a significant lowering of the plasma calcium concentration in 90 minutes. The rate of decrease of plasma calcium is consistent with the hypothesis that calcitonin is released by magnesium in high concentrations. There was no decrease in the plasma calcium concentration in cats of the same weight thyroparathyroidectomized 60 min before an identical magnesium chloride infusion or an infusion of isotonic sodium chloride at the same flow rate. The hypercalciuric effect of magnesium could not account for the hypocalcaemic effect of magnesium. Plasma magnesium concentration during magnesium infusion into cats with an intact thyroid-parathyroid gland complex was slightly, but not significantly higher than in acutely thyroparathyroidectomized cats.

scholarly journals Biocatalytic Transformation of 5-Hydroxymethylfurfural into 2,5-di(hydroxymethyl)furan by a Newly Isolated Fusarium striatum Strain

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Alberto Millán ◽  
Núria Sala ◽  
Mercè Torres ◽  
Ramon Canela-Garayoa
Keyword(s):  
Fusarium Species ◽  
Inoculum Size ◽  
High Recovery ◽  
23 Factorial Design ◽  
Organic Solvent Extraction ◽  
Working Volume ◽  
The Media ◽  
Substrate Feeding ◽  
High Concentrations ◽  
Reaction Media

The compound 2,5-di(hydroxymethyl)furan (DHMF) is a high-value chemical block that can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated, and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evaluated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The process was successfully scaled-up at bioreactor scale (1.3 L working volume) with excellent DHMF production yields (95%) and selectivity (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.

THE EFFECT OF SALMINE ON BACTERIA

1958 ◽  
Vol 4 (2) ◽  
pp. 65-71 ◽  
Author(s):  
Thomas D. Brock
Keyword(s):  
Sodium Chloride ◽  
Gram Negative Bacteria ◽  
Bacteriostatic Activity ◽  
Bactericidal Action ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Surface ◽  
Bactericidal Effects

The bacteriostatic and bactericidal effects of salmine on various bacteria have been studied. Salmine has more bacteriostatic activity against Gram-positive than against Gram-negative bacteria. It is bactericidal in water but not in broth, and this bactericidal action occurs against both Gram-positive and Gram-negative bacteria. It has been shown that salmine causes agglutination of washed suspensions of certain bacteria and this agglutination is not correlated directly with the Gram stain. Salmine causes an increase in the turbidity of washed cells of all bacteria, Gram-positive and Gram-negative, and differs in this respect from the solutes sodium chloride and glucose, which affect only Gram-negative species.A comparison has been made of the effects of salmine and polymyxin and it has been concluded that salmine may also act by attachment to the bacterial surface.

The effect of salinity on the growth, water status, and ion content on Common bean (Phaseolus vulgaris. L. var. El-Djadida)

2018 ◽  
Vol 7 (4) ◽  
pp. 147-156
Author(s):  
Laredj-Zazou Rahma ◽  
Toumi Benali Fawzia ◽  
Bouazza Sofiane
Keyword(s):  
Sodium Chloride ◽  
Water Status ◽  
Phaseolus Vulgaris L ◽  
Salt Stress Tolerance ◽  
Ion Content ◽  
Organic Growth ◽  
Growth Attributes ◽  
High Concentrations ◽  
High Level ◽  
Post Stress

Stress salinity has an important effect on crops physiology. The scope of our study was to evaluate the effect of salt stress tolerance as determined through growth attributes, water status and ion content in (Phaseolus vul-garis. L), the variety of El-Djadida in 6 weeks post stress application. The ex-periment was performed under glasshouse, in controlled conditions, in pots and irrigated with nutrient solution of Hoagland. Plants were irrigated with water containing sodium chloride alone (100 and 200 meq.l-1) combined with sodium chloride (NaCl) and calcium chloride (CaCl2) (100 and 150 meq.l-1). The results obtained showed that the salt application had a depressive effect on the organic growth however, this trend was dependant on the intensity of the stress. The hydric state of the plant varied with the concentration of sub-strate, thus exhibiting the ability to moderate the sensitive plant to adjust gradually to their osmotic pressure even by maintaining high concentrations of K+. The distribution of Na+, K+ and Ca++ in plant organs leaves and roots highlighted that the high level of salinity increased with levels of Na+ which inhibited the absorption of Ca++ and K+ ions.

scholarly journals The Effect of Salinity on Fruit Quality and Yield of Cherry Tomatoes

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 59
Author(s):  
Carlos Agius ◽  
Sabine von Tucher ◽  
Wilfried Rozhon
Keyword(s):  
Sodium Chloride ◽  
Fruit Quality ◽  
Plant Pathogens ◽  
Titratable Acidity ◽  
Sodium Content ◽  
Soluble Solids ◽  
Glucose Levels ◽  
High Concentrations ◽  
Cherry Tomatoes

Hydroponic cultivation of vegetables avoids problems with soil-borne plant pathogens and may allow higher yield. In arid climates and particularly on islands, high concentrations of sodium chloride can be present in the groundwater. For instance, in many sites of Malta, the groundwater contains more than 10 mM sodium chloride. Here we investigated the effects of sodium chloride at levels typically found in Malta on yield, physiology and fruit quality of tomato, the economically most important vegetable. We selected cherry tomatoes since their production is attractive due to their high marketing value. While the yield declined at higher salinity levels tested (17 and 34 mM), the quality increased significantly as indicated by higher total soluble solids and fructose and glucose levels. The type of substrate—coco peat, perlite or Rockwool—had only minor effects. Although the concentration of citric acid and malic acid remained unaffected, the pH dropped by approximately 0.1 unit and the titratable acidity increased slightly. This might be explained by a high uptake of chloride but a lower increase of the sodium content and a reduced potassium level in the fruits, shifting the equilibrium of the organic acids more to their protonated forms. Proline increased significantly, while the level of glutamic acid, which is crucial for the taste, remained unchanged. Our results show that cherry tomatoes can be cultivated in nutrient solutions prepared with salt-containing groundwater, as found in Malta. The yield declined to some extent but the quality of the produced fruits was higher compared to cultivation in salt-free media.

scholarly journals Antimicrobial and antibiofilm properties of essential oils from Piper marginatum Jacq.

2021 ◽  
Vol 10 (11) ◽  
pp. e514101119967
Author(s):  
Ana Lúcia Mendes dos Santos ◽  
Filipe Augusto Matos Araújo ◽  
Érika da Silva Matisui ◽  
Luiz Antonio Mendonça Alves da Costa ◽  
Alexandre José Macêdo ◽  
...  
Keyword(s):  
Essential Oils ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Folk Medicine ◽  
Gram Negative Bacteria ◽  
Biofilm Inhibition ◽  
Future Developments ◽  
Phytochemical Constituents ◽  
Amazonian Region

A low shrub growing in the Amazonian region, Piper marginatum Jacq. has been related to the treatment of a disease variety in folk medicine, however, still lacking scientific support. This study aimed to describe the composition of essential oils obtained from leaves (EOL) and branches (EOB) of P. marginatum and their antimicrobial effects on six relevant pathogenic bacteria. A combination of GC-FID and GC-MS was used to identify the phytochemical constituents. As antimicrobial assays, the oils were screened at the minimum inhibitory concentration (MIC) of 3 µg/ml for planktonic and biofilm inhibition. EOL revealed the presence of trans–nerolidol, o–cymene, spathulenol, elemicin, and α–copaene, while EOB composition was mainly of myristicin, trans-caryophyllene, trans-nerolidol, caryophyllene oxide, α–copaene, γ–muurolene and spathulenol. The strongest inhibition of planktonic growth was achieved against Pseudomonas aeruginosa (EOB) and Escherichia coli (EOB). Overall, Gram negative bacteria were more sensitive to both EOB/EOL showing less ability of growth and biofilm formation. The Gram-positive strains seemed to react to the essential oils by massive adhesion. Our results corroborate the relevance of Piperaceae and indicate the possible use of P. marginatum in future developments of antimicrobials.

scholarly journals Using sub-micron silver-nanoparticle based films to counter biofilm formation by Gram-negative bacteria

2018 ◽  
Vol 442 ◽  
pp. 288-297 ◽  
Author(s):  
A.R. Gillett ◽  
S.N. Baxter ◽  
S.D. Hodgson ◽  
G.C. Smith ◽  
P.J. Thomas
Keyword(s):  
Silver Nanoparticle ◽  
Biofilm Formation ◽  
Gram Negative Bacteria ◽  
Gram Negative

Effects of lactate and glutamine on palmitate metabolism in rat kindey cortex

1976 ◽  
Vol 231 (1) ◽  
pp. 14-19 ◽  
Author(s):  
M Barac-Nieto
Keyword(s):  
Renal Cortex ◽  
Palmitate Oxidation ◽  
The Media ◽  
High Concentrations ◽  
Rat Renal Cortical Slices ◽  
Very High ◽  
Cortical Slices ◽  
Palmitate Metabolism ◽  
Low Rate

Rat renal cortical slices were incubated with [1-(14)C]palmitate bound to 2.5% albumin. The following effects were found: a)1 mM palmitate utilization or oxidation to CO(2) varied according to the concentration of lactate in the media, it increased at 0.8 and 3.2 mM, was unchanged at 8 mM, and decreased at 16 mM. Esterification was stimulated at 3.2 mM lactate. b) Addition of glutamine (0.1 mM) instead of lactate stimulated incomplete and complete oxidation of palmitate (1 mM), whereas high medium glutamine (10 mM) inhibited palmitate (1 mM) utilization, esterification, and oxidation to CO(2) but increased its incomplete oxidation. The low rate of exogenous palmitate oxidation observed in this study and the finding that exogenous palmitate oxidation is only partially inhibited at very high concentrations of exogenous lactate or glutamine are consistent with the view that these exogenous substrates contribute little to the oxidative metabolism of rat renal cortex in vitro, which probably depends on the supply of substrates endogenous to the tissue.

scholarly journals Relationship Between Membrane Vesicles, Extracellular ATP and Biofilm Formation in Antarctic Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nicolas Baeza ◽  
Elena Mercade
Keyword(s):  
Biofilm Formation ◽  
Membrane Vesicles ◽  
Metabolic Cost ◽  
Extracellular Atp ◽  
Gram Negative Bacteria ◽  
Bacterial Survival ◽  
Gram Negative ◽  
Two Factors ◽  
And Control

Abstract Biofilms offer a safe environment that favors bacterial survival; for this reason, most pathogenic and environmental bacteria live integrated in biofilm communities. The development of biofilms is complex and involves many factors, which need to be studied in order to understand bacterial behavior and control biofilm formation when necessary. We used a collection of cold-adapted Antarctic Gram-negative bacteria to study whether their ability to form biofilms is associated with a capacity to produce membrane vesicles and secrete extracellular ATP. In most of the studied strains, no correlation was found between biofilm formation and these two factors. Only Shewanella vesiculosa M7T secreted high levels of extracellular ATP, and its membrane vesicles caused a significant increase in the speed and amount of biofilm formation. In this strain, an important portion of the exogenous ATP was contained in membrane vesicles, where it was protected from apyrase treatment. These results confirm that ATP influences biofilm formation. Although the role of extracellular ATP in prokaryotes is still not well understood, the metabolic cost of its production suggests it has an important function, such as a role in biofilm formation. Thus, the liberation of extracellular ATP through membrane vesicles and its function deserve further study.

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