NaCl Concentration Research Articles

Salinity stress-induced impacts on biomass production, bioactive compounds, antioxidant activities and oxidative stress in watermeal (Wolffia globosa)

This study investigated the impact of salinity stress on the biomass production, proximate composition and bioactive contents, antioxidant activities, and oxidative stress parameters of Wolffia globosa. Wolffia was exposed to variable NaCl concentrations (0, 8.56, 17.11, 25.67, 34.22, and 42.78 mM) in nutrient-replete nutrient conditions under natural sunlight in a transparent polyhouse. The net biomass gain (NBG; 131.17 g), crude protein (33.16%) and crude lipid content (4.9%) were significantly high at 8.56 mM NaCl compared to control and most of other treatments. Total phenolic content peaked at 17.11 mM NaCl (551.39 mg GAE g−1), while total tannin content was highest at 25.67 mM NaCl (13.38 mg TAE g−1). Total flavonoid content, vitamin C, oxidative stress enzymes; superoxide dismutase, catalase, and lipid peroxidation (malondialdehyde, MDA) peaked at 42.78 mM NaCl, with values of 140.52 mg QE g−1, 218.69 mg 100 g−1, 28.18 U g−1 FW, 288.60 U min−1 g−1 FW, and 142.32 mg MDA kg−1, respectively. The control invariably had the lowest values. Total carotenoid content was significantly higher at 17.11 and 25.67 mM NaCl (1812.84 and 1749.10 μg g−1), while Chlorophyll-a (Chl-a) was highest at 17.11 mM (21.33 μg g−1). Chlorophyll-b (Chl-b) peaked at 17.11, 25.67, and 34.22 mM NaCl levels. Salinity stress generally elevated antioxidant activities, assessed via DPPH, ABTS, and FRAP assays reaching their highest values at 34.22 mM NaCl (40.52%), 17.11 mM NaCl (56.71%), and 25.67 mM NaCl (428.83 μmol Fe2⁺ g−1), respectively. FT-IR profiles indicated changes in chemical composition and functional groups due to salt stress. Overall, salinity significantly influenced the proximate composition, antioxidant activities, bioactive compounds and oxidative stress enzyme activities of wolffia.

A solar-powered electrocoagulation process with a novel CNT/silver nanowire coated basalt fabric cathode for effective oil/water separation: From fundamentals to application.

Electrocoagulation (EC) has proven its high efficiency and environmental sustainability for treating several types of wastewaters. However, the primary drawbacks of the conventional EC process are the suitable electrode materials and the relatively high cost due to the requirement for electric energy. To overcome these practical challenges, this study investigated effective oil/water separation by a solar-powered electrocoagulation (SPEC) process using a novel highly conductive basalt fabric (BF) cathode. The BF cathode was fabricated using a simple approach: dip-coating in carbon nanotubes (CNT) dispersion, followed by a bath exhaustion coating in a silver nanowires (AgNws) solution, and its successful preparation was confirmed through several advanced characterization techniques. The effect of the CNT-AgNws coating on the electrical conductivity of the BF-CNT/AgNws was investigated using the four-probe tester. The BF-CNT/AgNws cathode exhibited a high conductivity of 1.66×104S/m, which indicates its applicability in the SPEC system. Under the operating conditions of applied voltage (25V), SPEC time (30min), stirring rate (150rpm), and NaCl concentration (1g/L), the experiment's results showed a high COD removal of 90.2±0.03 %, a low energy consumption of 1.28±0.01 kWh/kgCOD, and electrode consumption of 0.35±0.06kg/m3. In addition, due to the use of solar-powered energy, the overall cost was reduced by eliminating the electricity fees. Moreover, the reusability test results proved that the BF cathode has potential reusability in successive SPEC experiments while maintaining its performance. In conclusion, the obtained findings are very encouraging in designing novel EC cathodes for effective oily wastewater treatment at an industrial scale.

Primary Recovery of Carboxymethyl Cellulase from Thermophilic Bacillus licheniformis 2D55 Using an Aqueous Two-phase System

This study uses an aqueous two-phase system developed from a polymer and salt to purify a thermostable carboxymethyl cellulase (CMCase) produced by thermophilic Bacillus licheniformis 2D55. The effects of system parameters, such as polyethene glycol (PEG) molar mass, salt concentration, crude load, NaCl concentration and pH on partitioning and recovery efficiency, are evaluated. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) is used to determine the purity of the CMCase. The enzyme is successfully purified, achieving a 10.9-fold purification and 86.62% yield. The maximum purification condition is achieved in ATPS comprising 20.5% PEG 8000/15% sodium citrate, with a crude load of 17% (w/w), NaCl of 1.0% (w/w) and pH at 7.0. Under these conditions, a partition co-efficient of 0.21 is observed, indicating that CMCase preferentially partitions to the bottom phase. These results demonstrate the potential of ATPS for the purification of thermostable CMCase from the fermentation broth of thermophilic Bacillus licheniformis 2D55.

Tailoring amino-functionalized n-alkyl methacrylate ester-based bio-hybrids for adsorption of methyl orange dye: Controllable macromolecular architecture via polysaccharide-integrated ternary copolymerization.

Controllable macromolecular architecture formation via polysaccharide integrated ternary copolymerization was explored in the design of amino-functionalized n-alkyl methacrylate ester-based biohybrids. Ternary poly(dimethylaminoethyl methacrylate-co-glycidyl methacrylate-co-hydroxypropyl methacrylate)/sodium-alginate, PDGH/ALG, hybrids were designed using anionic polysaccharide through in-situ radical polymerization. An insight into the effect of ALG on physicochemical structure of ternary hybrids, particularly the interactions between polymeric chains, was created. In addition to incorporation of ALG, the effect of polymerization under cryocondition on mechanical stiffness of hybrids was investigated. Adding 0.5 % ALG to ternary PDGH matrix resulted in a 4.2-fold increase in compressive modulus. Swelling of hybrid hydrogels prepared at 1 °C decreased by 5 times, while a 3.4-fold decrease was observed in hybrid cryogels formed at -18 °C. ALG-rich hybrids showed "salting-in" behavior with increasing salt concentration in NaCl, KCl and MgCl2 solutions, while hybrids with low ALG-content exhibited "salting-out" behavior. The hybrid gels were applied to adsorption of anionic dye methyl orange (MO) from simulated dye wastewater. The adsorption was found to follow Freundlich mechanism and a pseudo-second-order kinetic model. ALG-integrated hybrid gels showed a high desorption efficiency and a longer lifespan during the regeneration process, thus showing potential to be used for anionic dye removal from textile wastewater in industry.

The Impact of Abiotic Environmental Stressors on Fluorescence and Chlorophyll Content in Glycine max (L.) Merrill

In this study, we present the results of the impact of abiotic environmental (chemical) stressors in the soil environment (salinity, acidification, inorganic elements from industry—red mud waste containing Al) on the content and fluorescence of chlorophyll in the assimilating tissues of Glycine max (L.) Merrill, cv. ES Mentor. Under controlled conditions of a pot experiment during the 2023 growing season, we applied graded doses of these stressors (salinity—doses of 20, 30, and 60 g NaCl per 2 dm3 of water used for plant irrigation; acidity—pH 6, pH 5, and pH 4; red mud—200 g, 400 g, and 600 g per pot) and assessed their impact on the effective and maximum quantum yield of photosystem II (PSII), yield Y(II), or the ratio of variable to maximum fluorescence—the Fv/Fm test. These tests are used to detect plant stress. The Y(II) test yielded values in the range of 0.627–0.800. Significant differences (variance analysis, 95% Least Significant Difference—LSD, post hoc test of analysis of variance—ANOVA) in reducing PSII chlorophyll fluorescence (Y(II)) were found between the medium and high doses of all three stressors compared to the control, indicating plant stress response. The Fv/Fm test yielded values between 0.668 and 0.805 and similarly detected stress responses in plants to all medium and high doses of stressors. The evaluated cultivar showed tolerance to moderately increased salt (NaCl) content and red mud levels. This was also confirmed by the chlorophyll content expressed as the Chlorophyll Content Index (CCI). The highest (significantly confirmed) chlorophyll content was found in the control variant and the variants with lower salt content and a soil pH of 6, with values of 35.633–37.467 CCI, compared to variants with higher red mud content (15.533–18.133 CCI) and higher soil acidity with pH 4 (22.833 CCI). Based on the results obtained, we conclude that the ES Mentor cultivar is tolerant to lower doses of the assessed stressors and can be cultivated in agricultural practice. However, medium to high doses of stressors trigger a strong stress response in plants and, therefore, we do not recommend cultivating this variety in contaminated environments.

Formation of Highly Negatively Charged Supported Lipid Bilayers on a Silica Surface: Effects of Ionic Strength and Osmotic Stress.

Solid supported lipid bilayers (SLBs) serve as an excellent platform for biophysical studies. However, the formation of highly negatively charged SLBs on negatively charged surfaces remains a challenge due to electrostatic repulsion. Here, we study the effects of ionic strength and osmotic stress on the formation of highly negatively charged SLBs on the silica surface. We used quartz crystal microbalance-dissipation to study the adsorption and rupture of highly negatively charged small unilamellar vesicles on the silica surface in different concentrations of NaCl and under different osmotic stresses. It was demonstrated that an increase in the ionic strength of the solution enhances SLB formation. Both hypertonic and moderate hypotonic osmotic stress can promote the formation of SLBs. However, the SLB cannot be formed under high hypotonic osmotic stress. Importantly, osmotic stress alone without a change in ionic strength is insufficient to promote SLB formation. Moreover, the topographical images obtained by atomic force microscopy showed that complete bilayers were formed under hypertonic osmotic stress and high ionic strength, whereas defects were noticed in the bilayers formed under hypotonic osmotic stress. Furthermore, the fluidity of the lipid bilayers was studied by fluorescence recovery after photobleaching. A higher membrane fluidity was observed for the complete lipid bilayers compared to that of the lipid bilayers with defects. Our findings further the understanding of how ionic strength and osmotic stress affect the formation of highly negatively charged SLBs on negatively charged surfaces, providing insights for preparing model biological membranes.

Dynamic Light Scattering Analysis of Lipid Nanoparticles: Effect of Salts on the Diffusion Interaction Parameter and Hydrodynamic Radius at Infinite Dilution.

The rise in the popularity of lipid nanoparticle (LNP)-based formulations necessitates the need for screening tools to quickly predict their colloidal stability in the presence of common excipients. Protein chemists have employed the diffusion interaction parameter (kD) determined using dynamic light scattering as an indicator of formulation stability, yet this approach has not been applied to particulate systems. Herein, kD measurements of LNPs revealed behavior dissimilar to that of proteins. LNP interactions were inherently weakly attractive and unaffected by increasing concentrations of NaCl. The small change in the value in the presence of different salts was dependent upon salt molecular identity and consistent with the Hofmeister series. In addition, calculation of the hydrodynamic radius at infinite dilution (RH,0) revealed a slight reduction in the LNP size with increasing NaCl concentration. Overall, while traditional kD measurements provide limited information about LNP stability, the assay provides insight into physical changes to LNP in the presence of excipients via extrapolation of the diffusion coefficient to infinite dilution.

Kineococcus halophytocola sp. nov., Isolated from Leaves of Halophyte Sesuvium portulacastrum L.

An aerobic, Gram-stain-positive, motile, coccus-shaped actinomycete, designated strain LSe6-4T, was isolated from leaves of sea purslane (Sesuvium portulacastrum L.) in Thailand and subjected to a polyphasic taxonomic studies. Growth of the strain occurred at temperatures between 15 and 38°C, and with NaCl concentrations 0-13%. The 16S rRNA gene sequences analysis indicated that the strain was most closely related to Kineococcus endophyticus KLBMP 1274T (99.2%), and Kineococcus mangrovi L2-1-L1T (99.0%). The genome of strain LSe6-4T was estimated to be 4.22 Mbp in size, with DNA G+C content of 74.57%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) relatedness values between strain LSe6-4T and the closely related species were less than the threshold values for identifying a novel species. Strain LSe6-4T showed morphological and chemotaxonomic characteristics of the genus Kineocoocus. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, with arabinose, galactose, and ribose as whole-cell sugars. The predominant menaquinone was MK-9(H2). The polar lipid profile composed of phosphatidylglycerol, diphosphatidylglycerol, an unidentified phospholipid, three unidentified aminophospholipids, and an unidentified aminolipid. Major cellular fatty acids (> 10% of total fatty acids) were anteiso-C15:0 and iso-C14:0. It is evident from the combination of genotypic and phenotypic characteristics that strain LSe6-4T represents a novel species of the genus Kineococcus, for which the name Kineococcus halophytocola sp. nov. is proposed. The type strain is strain LSe6-4T (= TBRC 17798T = NBRC 116401T).

Probing the Interaction Mechanisms of Dodecane and Mica/Calcite: Implications for Oil Recovery.

Understanding the interfacial interaction mechanisms between oil and minerals is of vital importance in the applications of petroleum production and environmental protection. In this work, the interactions of dodecane with mica and calcite in aqueous media were investigated by using the drop probe technique based on atomic force microscopy. For the dodecane-mica interactions, the electrical double layer (EDL) repulsion dominated in 10 mM NaCl solution, and a higher pH facilitated the detachment of dodecane. The EDL interaction was diminished with an elevated NaCl concentration, and the van der Waals (vdW) attraction triggered the oil attachment on the mica surface. In the presence of Ca2+ and Mg2+, the EDL repulsion was weakened leading to a thinner water film, and the oil attachment occurred. For the dodecane-calcite interactions, large adhesions were observed under all of the solution conditions, mainly attributed to the ionic bridging by Ca2+ formed during calcite dissolution. At pH 4, CO2 bubbles appeared on the calcite surface, resulting in a repulsive vdW interaction between dodecane and the surface, which hindered the adhesion. The calcite surface wettability was modified in high concentrations of NaCl, leading to a reduced adhesion with oil. The ionic bridging effect was promoted, and the adhesion was enhanced in 500 mM Ca2+ and Mg2+ solutions. At pH 10, the precipitates of Ca(OH)2(s) and Mg(OH)2(s) appeared on the calcite surface, which diminished the adhesion. Our results provided fundamental insights into the mechanisms of oil-water-mineral interactions, which contributed to the understanding and modulation of engineering processes in the enhancement of oil pollutant removal and oil recovery.

Further Characterization of Lipase B from Ustilago maydis Expressed in Pichia pastoris: a Member of the Candida antarctica Lipase B-like Superfamily.

Lipases from the basidiomycete fungus Ustilago maydis are promising but underexplored biocatalysts due to their high homology with Candida antarctica lipases. This study provides a comprehensive characterization of a recombinant CALB-like lipase from U. maydis, expressed in Pichia pastoris (rUMLB), and compares its properties with those of the well-studied recombinant lipase B from C. antarctica (rCALB). Biochemical analyses included evaluations of optimal pH, temperature, triglyceride (TG) preference for short- and medium-chain acyl groups, phospholipase and amidase activities, enantiopreference, thermostability, stability in organic solvents, and response to NaCl concentrations. rUMLB, a glycosylated enzyme with a molecular weight of 38.6kDa, exhibited cold-active behavior at 0°C and preferred hydrolysis of partially soluble short-chain fatty acid TGs, like rCALB. In addition, rUMLB was also capable of hydrolyzing insoluble long-chain triglycerides like rCALB. The half-life at 50°C for rCALB was approximately 1.6 times greater than that of UMLB, which has fewer surface-exposed proline residues. Both enzymes displayed strong (R)-enantiopreference on (R)-glycidyl butyrate, (R)-ethyl hydroxy butyrate, and (R)-methyl hydroxy valerate enantiomers with increased activity in non-polar solvents. However, rUMLB was more sensitive to polar solvents. Notably, rUMLB was activated at high NaCl concentrations, as previously reported for rCALB. rUMLB showed amidase activity on capsaicinoids similar to rCALB; however, rUMLB uniquely demonstrated significant phospholipase activity toward natural phospholipids, a feature not observed in rCALB. The analysis of the cavity adjacent to the active site in the UMLB model and CALB structure revealed slightly larger area, volume, and hydrophobicity values for UMLB. These comparative insights highlight the functional diversity within the CALB-type lipase family, underscoring the potential of UMLB as a versatile biocatalyst and providing valuable information for biotechnological applications and for understanding enzyme structure-function relationships within the CALB superfamily.

Coupling between topological edge state and defect mode-based biosensor using phononic crystal

A wealth of details regarding an individual’s state of health, like a person’s respiratory and metabolic functioning, can be studied by analyzing the volatile molecules and atoms in human exhaled breath. Besides, the salinity of seawater is a crucial factor in understanding its characteristics because any variation in the salinity of seawater represents the variations in the hydrological, biological, and chemical distributions. In this paper, a symmetrical one-dimensional phononic structure is theoretically designed using two symmetrical crystals separated with a defective cavity. This structure has been designed to excite a topological edge state coupled with defect mode. The coupled mode achieves high sensitivity to NaCl concentration in an aqueous solution, seven times higher than the defective one. By ranging the NaCl concentration from 0 to 21%, the average sensitivity is 467 and 3160 Hz/% for defect mode and coupled modes, respectively. The bandwidth of the coupled mode of 170 Hz is much narrower than that of the defect mode of 671 Hz for detecting salinity. For detecting the increase in concentration in dry exhaled breath by ranging the concentration from 0 ppm to 100 ppm, the average sensitivity is Hz/ppm for coupled mode. As a result of these enhancements in the sensitivity and bandwidth of the coupled mode, the coupled mode is recommended to be used in different biosensing applications.

The application of design of experiments and artificial neural networks in the evaluation of the impact of acidic conditions on cloud point extraction.

This study aimed to analyze the impact of acidic conditions on the recovery of ciprofloxacin and levofloxacin for cloud point extraction with the Design of Experiments and Artificial Neural Networks. The design included 27 experiments featuring three repetitions of the central point for both drugs. The tested parameters included Triton X-114 concentration, HCl concentration, NaCl concentration, and incubation temperature, which were coded at five levels. After extraction, samples were analyzed using HPLC, and statistical analysis was performed using Statistica software. Polynomial equations were developed to predict recovery values based on the experimental conditions. Results indicated that Triton X-114 concentration had the most significant impact on recovery for ciprofloxacin and levofloxacin, while HCl concentration also played an important role. The highest recovery for ciprofloxacin was observed for the following conditions: 8.5 % TX-114, 0.1 M HCl, temperature of incubation 45 °C, and no addition of NaCl. The highest recovery for levofloxacin was observed under the following conditions: 9 % TX-114, 1.5 M HCl, temperature of incubation 60 °C, and no addition of NaCl. The observed recoveries were 43 % and 53 % for levofloxacin and ciprofloxacin, respectively. They were in accordance with the predicted values calculated with DoE and with ANN approach, These findings validate the use of the Central Composite Design and Artificial Neural Networks for analyzing how acidic conditions affect the recovery of both drugs, allowing for detailed analysis and optimization of the influencing factors.

A Novel Wild-Type Lacticaseibacillus paracasei Strain Suitable for the Production of Functional Yoghurt and Ayran Products

Raw goat and ewe’s milk samples were used for the isolation of seven lactic acid bacteria new strains. After testing hemolytic activity and resistance to antibiotics, specific functional properties were evaluated; Lactococcus lactis subsp. lactis FBM_1321 and Lacticaseibacillus paracasei FBM_1327 strains resulted in the highest cholesterol assimilation percentages ranging from 28.78 to 30.56%. In addition, strong adhesion capacity to differentiated Caco-2 cells (1.77–21.04%) was mapped, and the lactobacilli strains exhibited strong antagonistic activity against foodborne pathogens compared to lactococci. The strains were able to grow at low pH and high NaCl concentrations, conditions that prevail in food systems (cell counts ranged from 1.77 to 8.48 log CFU/mL after exposure to pH 3 and from 5.66 to 9.52 log CFU/mL after exposure to NaCl concentrations up to 8%). As a next step, freeze-dried immobilized Lc. paracasei FBM_1327 cells on oat flakes were used for the preparation of functional yoghurt and ayran products. Cell loads of the functional strain remained high and stable in both products (7.69 log CFU/g in yoghurt and 8.56 log CFU/g in ayran after 30 days of storage at 4 °C) throughout their shelf life. No significant changes in the volatile profile were noticed, and the new products were accepted by the panel during the sensory evaluation.

Comparative metabolomic analysis of Haematococcus pluvialis during hyperaccumulation of astaxanthin under the high salinity and nitrogen deficiency conditions.

Revealing the differences of metabolite profiles of H. pluvialis during hyperaccumulation of astaxanthin under the high salinity and nitrogen deficiency conditions was the key issues of the present study. To investigate the optimum NaCl and NaNO3 concentration and the corresponding metabolic characteristic related to the astaxanthin accumulation in H. pluvialis, a batch culture experiment was conducted. The results indicated that 7.5g·L- 1 and 0g·L- 1 (nitrogen deficiency) were the optimum NaCl and NaNO3 levels for the astaxanthin accumulation respectively, under which the highest astaxanthin contents reached up to 7.51mg·L- 1 and 5.60mg·L- 1. A total of 132 metabolites were identified using LC-MS/MS technique, among which 30 differential metabolites with statistical significance were highlighted. Subsequently, 18 and 10 differential metabolic pathways in the high salinity (HS) and nitrogen-deficient (ND) treatments were extracted and annotated respectively. The values of Fv/Fm, Yield and NPQ were all at the highest level in the ND group during the experiment. The levels of the metabolites in the ND group were almost lower than those both in the control (CK) and HS group, while which in the HS group were substantially at the higher or close levels compared to the CK group. Finally, 7 metabolic markers related to the astaxanthin accumulation were highlighted in the HS and ND group respectively. L-Proline, L-Aspartate, Uridine 5'-monophosphate (UMP), Succinate, L-2-Hydroxygluterate, L-Valine and Inosine 5'-monophosphate (IMP) were identified as the metabolic markers in the HS group, whose fold change were 0.85, 4.14, 0.31, 0.66, 3.10, 1.32 and 0.30. Otherwise, the metabolic markers were Glyceric acid, Thymine, sn-Glycerol 3-phosphate, Glycine, Allantoic acid, L-Valine and IMP in the ND group, with the fold change 0.23, 2.11, 0.38, 0.41, 0.50 and 2.96 respectively. The results provided the comparative metabolomic view of astaxanthin accumulation in H. pluvialis under the different cultivation conditions, moreover showed a novel insights into the astaxanthin production.

Rheological Behavior of Gassy Marine Clay: Coupling Effects of Bubbles and Salinity

Understanding the rheological behavior of marine clay is crucial to analyzing submarine landslides and their impact on marine resource exploitation. Dispersed bubbles in marine clay (gassy clay) and electrolytes in seawater (e.g., NaCl concentration of 0.47 M) significantly impacts rheological properties. Under low ionic strength and low pore water pressure conditions, dispersed bubbles have a strengthening effect on the yield stress and the viscosity of clays. This effect turns into a weakening effect when the pore water pressure reaches 300 kPa or the ionic strength exceeds 0.18 M. It was proposed that the effect of bubbles, whether strengthening or weakening, was determined by the size of bubbles with respect to the characteristic size of the particle structure formed by clay particles. A theoretical model was developed, which reasonably captures rheological behaviors of gassy clays.

Role of single and mixed culture of Pseudomonas aeruginosa and Serratia ficaria in utilization of petroleum wastes of Dora- refineries.

The ability of single and mixed bacterial culture to utilize Dora-refineries petroleum wastes was compared. Pseudomonas aeruginosa and Serratia ficaria mixed culture consumed the wastes better than the single bacterial cultures. The highest log. number of viable cells in mixed culture was 6.842 , while in single bacterial cultures it was 6.683 and 5.631, respectively. after 3 days in API medium containing the refinery wastes. The effect of some environmental conditions on the degradation of petroleum wastes was studied included aeration , NaCl concentration , pH and temperature. The growth of bacteria in the agitated culture was higher than stagnant culture the log. of cell no. was 6.021 in the first culture. The highest log. of cell no. stagnant culture was 5.771. Pseudomonas aeruginosa AA22 and Serratia ficaria AA39 were able to grow in medium containing 5 , 7 % NaCl , they favorite pH 7. The mixed culture of the two bacteria grew well of 45 oC.

Luminal flow in the connecting tubule induces afferent arteriole vasodilation.

Renal autoregulatory mechanisms modulate renal blood flow. Connecting tubule glomerular feedback (CNTGF) is a vasodilator mechanism in the connecting tubule (CNT), triggered paracrinally when high sodium levels are detected via the epithelial sodium channel (ENaC). The primary activation factor of CNTGF-whether NaCl concentration, independent luminal flow, or the combined total sodium delivery-is still unclear. We hypothesized that increasing luminal flow in the CNT induces CNTGF via O2- generation and ENaC activation. Rabbit afferent arterioles (Af-Arts) with adjacent CNTs were microperfused ex-vivo with variable flow rates and sodium concentrations ranging from < 1 to 80mM and from 5 to 40 nL/min flow rates. Perfusion of the CNT with 5mM NaCl and increasing flow rates from 5 to 10, 20, and 40 nL/min caused a flow-rate-dependent dilation of the Af-Art (P < 0.001). Adding the ENaC blocker benzamil inhibited flow-induced Af-Art dilation, indicating a CNTGF response. In contrast, perfusion of the CNT with < 1mM NaCl did not result in flow-induced CNTGF vasodilation (P > 0.05). Multiple linear regression modeling (R2 = 0.51; P < 0.001) demonstrated that tubular flow (β = 0.163 ± 0.04; P < 0.001) and sodium concentration (β = 0.14 ± 0.03; P < 0.001) are independent variables that induce afferent arteriole vasodilation. Tempol reduced flow-induced CNTGF, and L-NAME did not influence this effect. Increased luminal flow in the CNT induces CNTGF activation via ENaC, partially due to flow-stimulated O2- production and independent of nitric oxide synthase (NOS) activity.

Effects of Enterobacter cloacae extract, selenium nanoparticles and methyl jasmonate on shoot liquid cultures of Sarcocornia fruticosa under salinity stress

BackgroundThe in vitro propagation of halophytes is innovative perspective for sustainable agriculture, conservation of natural plants and essential raw materials for industry due to increasing soil salinization and decreasing freshwater availability. Sarcocornia fruticosa, a halophytic plant, may hold promise for biosaline production systems and achieve bioactive products. Understanding the salt tolerance mechanisms of halophytes through elicitors can enhance the production of secondary metabolites, such as phenolics and flavonoids, under saline environment. This study aimed to evaluate the effects of NaCl salinity (700 mM and 1000 mM) on Sarcocornia fruticosa shoot cultures and assess the influence of different elicitors-Enterobacter cloacae extract (BE), selenium nanoparticles (SeNPs) and methyl jasmonate (MeJA) -on the plants growth, physiological and biochemical responses, and isorhamnetin production.MethodologyShoot cultures were grown under controlled conditions with two concentrations of NaCl, alone and in combination with BE (0.5%), SeNPs (100 ppm), or MeJA (50 µM). Growth parameters, photosynthetic pigments, ion accumulation, osmolyte content, oxidative stress marker, enzyme activity, phenolic compound levels, and isorhamnetin production were analyzed to determine the impact of salinity and elicitor treatments on S. fruticosa for 14 days.ResultsSarcorcocnia fruticosa exhibited better tolerance up to 700 mM than 1000 mM NaCl, as evidenced by higher dry weights, chlorophyll a/b ratios, and enhanced osmolyte and antioxidant contents. Elicitation both saline cultures with BE and SeNPs improved growth mostly by increasing biomass, pigment contents, K+/Na+ ratios, and reducing lipid peroxidation, however, MeJA reduced the biomass mainly by increasing MDA and Na+ ion accumulation. In contrast, application of all elicitors stimulated the production of phenolic compounds and isorhamnetin, as well as BE can contribute for increasing resistance of S. fruticosa to stressful conditions.ConclusionThis study demonstrated that PTC techniques and appropriate elicitors can optimize halophyte propagation and secondary metabolite production under saline conditions. The findings suggest that BE and SeNPs significantly enhanced the growth and biochemical resilience of S. fruticosa under salinity stress, with a notable increase in isorhamnetin production. MEJA.

Measurement and optimization of estimation method for moisture diffusivity of porous building materials with different salt content

Sintered bricks, common porous building materials in architectural heritage, necessitates an accurate understanding of moisture diffusivity for effective moisture transfer analysis. Using the “ruler method” proposed by Evangelides et al., based on pure water capillary absorption experiments, we determined the moisture diffusivity ( Dl) of Chinese sintered blue brick containing sodium chloride (NaCl) crystals. Before the experiments, the samples were immersed in 0%, 1%, 5%, and 10% NaCl solutions and dried to contain salt crystals. Subsequently, based on the Dl values measured by the ruler method, a heat and moisture coupled transfer model was developed to discuss the applicability of the moisture diffusivity obtained from the ruler method by reproducing the pure water capillary absorption process of sintered bricks with different salt contents. Experimental results showed that the capillary absorption coefficient ( Acap) and capillary moisture content ( wcap) of sintered bricks both decreased with increasing NaCl content, with maximum reductions of 18% and 8.6%, respectively. The Dl increased with elevated salt content in lower moisture content range but decreased in higher moisture content range. The simulation results indicated that the choice of boundary moisture content played an important role in the determination of moisture diffusivity in porous building materials and using saturated moisture content ( θsat) over capillary moisture content ( θcap) can give more suitable moisture diffusivity and the moisture content above θcap cannot be ignored in the ruler method. This research not only extends the ruler method’s applicability for sintered bricks but also provides support data for moisture simulations and conservation initiatives related to sintered brick architectural heritage.

The effect of environmental factors on transepithelial potential in a model Amazonian teleost, the tambaqui (Colossoma macropomum): Implications for sodium balance in harsh environments.

The tambaqui (Colossoma macropomum, G. Cuvier 1818) thrives both in the ion-poor waters of the Amazon and in commercial aquaculture. In both, environmental conditions can be harsh due to low ion levels, occasional high salt challenges (in aquaculture), low pH, extreme PO2 levels (hypoxia and hyperoxia), high PCO2 levels (hypercapnia), high ammonia levels (in aquaculture), and high and low temperatures. Ion transport across the gill is affected by active transport processes, passive diffusive permeability, ion concentrations (the chemical gradient), and transepithelial potential (TEP, the electrical gradient). The latter is a very important indicator of ionoregulatory status but is rarely measured. Using normoxic, normocapnic, ion-poor, low-dissolved organic carbon (DOC) well water (27°C, pH 7.0) as the acclimation and reference condition, we first confirmed that the strongly negative TEP (-22.3 mV inside relative to the external water) is a simple diffusion potential. We then evaluated the effects on TEP of more complex waters from the Rio Negro (strong hyperpolarization) and Rio Solimões (no significant change). Additionally, we have quantified significant effects of acute, realistic changes in environmental conditions-low pH (depolarization), hypercapnia (depolarization), hypoxia (depolarization), hyperoxia (hyperpolarization), elevated NaCl concentrations (depolarization), and elevated NH4Cl concentrations (depolarization). The TEP responses help explain many of the changes in net Na+ flux rates reported in the literature. We have also shown marked effects of temperature on TEP and unidirectional Na+ flux rates (hyperpolarization and decreased fluxes at 21°C, depolarization and increased fluxes at 33°C) with no changes in net Na+ flux rates. Calculations based on the Nernst equation demonstrate the importance of the TEP changes in maintaining net Na+ balance.