mM Of Salt Research Articles

Single-use chromatographic clarification to eliminate endonuclease treatment in production of recombinant adeno-associated viral vectors

In current manufacturing processes for recombinant adeno-associated viral vectors (rAAV), endonuclease treatment is used prior to depth filtration to break down host cell DNA that is released from cells post-lysis. Without this treatment, traditional depth filters exhibit negligible clearance of host cell DNA, a key process-related impurity. In this work, we evaluate single-use chromatographic clarification using Harvest RCTM filters (3 M) to process rAAV8 and rAAV9 HEK293 cell culture lysate with and without endonuclease pretreatment. We demonstrate endonuclease-free clarification for both serotypes with yield >90 % and up to 3 log reduction of host cell DNA, from >104 ng/mL to <50 ng/mL, matching or exceeding the filtrate quality in traditional depth filtration with 100 U/mL of endonuclease added during lysis. The addition of 100 mM of salt in the harvest buffer is also shown to improve filtration throughput, prevent filter clogging, and limit rAVV binding to the filter device. Finally, a mechanistic cake-fiber fouling model is shown to be a good representation of the Harvest RCTM filtration mechanism. The endonuclease-free clarification approach enables cost savings of USD 100,000 per 500 L batch, equivalent to the cost of cGMP-grade endonuclease at this scale. The benefits of endonuclease-free clarification further include easier raw material sourcing as well as eliminating the need for a residual endonuclease assay in rAAV manufacturing processes.

Salicylic Acid Improves Growth and Physiological Attributes and Salt Tolerance Differentially in Two Bread Wheat Cultivars.

Abiotic constraints such as salinity stress reduce cereal production. Salicylic acid is an elicitor of abiotic stress tolerance in plants. The aim of this study was to investigate the effects of salicylic acid on two bread wheat cultivars (SST806 and PAN3497) grown under salt stress (100 and 200 mM NaCl) in the presence and absence of 0.5 mM salicylic acid. The highest salt concentration (200 mM), in both PAN3497 and SST806, increased the days to germination and reduced the coleoptile and radicle dry weights. The shoot dry weight was reduced by 75 and 39%, root dry weight by 73 and 37%, spike number of both by 50%, spike weight by 73 and 54%, grain number by 62 and 15%, grain weight per spike by 80 and 45%, and 1000 grain weight by 9 and 29% for 200 and 100 mM NaCl, respectively. Salicylic acid in combination with 100 mM and 200 mM NaCl increased the shoot, root, and yield attributes. Salicylic acid increased the grain protein content, especially at 200 mM NaCl, and the increase was higher in SST806 than PAN3497. The macro-mineral concentration was markedly increased by an increase of NaCl. This was further increased by salicylic acid treatment for both SST806 and PAN3497. Regarding micro-minerals, Na was increased more than the other minerals in both cultivars. Mn, Zn, Fe, and Cu were increased under 100 mM and 200 Mm of salt, and salicylic acid application increased these elements further in both cultivars. These results suggested that salicylic acid application improved the salt tolerance of these two bread wheat cultivars.

Foliar Application of Spermidine Reduced the Negative Effects of Salt Stress on Oat Seedlings.

The effects of foliar application of spermidine (Spd) on the physiological aspects of salt-stressed oat seedlings were studied under greenhouse conditions. At the seedling stage, the salt-sensitive variety, namely, Caoyou 1 and the salt-tolerant variety, namely, Baiyan 2 were treated with 70 and 100 mM of salt, followed by the foliar application of 0.75 mM Spd or distilled water. Results showed that Spd application increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and reduced the rate of O2⋅– production and the accumulation of H2O2 and malondialdehyde (MDA). In addition, it increased the level of zeatin riboside (ZR) and the content of endogenous polyamines. The application of Spd increased the contents of soluble sugar, soluble protein, and free proline and helped maintain the osmotic balance of oat leaves. At the same time, foliar Spd treatment helped in maintaining the ion nutrition balance. Specifically, it reduced the content of Na+ and thereby stabilized the ratio of Na+/K+, Na+/Ca2+, and Na+/Mg2+. The effects of Spd application were more obvious for the salt-sensitive cultivar Caoyou 1 and under the lighter 70 mM salt stress.

Halophytes.tn: an innovative database for Tunisian halophyte plant identification, distribution and characterization.

Halophytes.tn (http://halophytes.rnrt.tn/) is a web-based database of Tunisian halophyte species. Halophytes are salt-tolerant plants able to grow above 85 mM of salt, even up to 2 M as for Tecticornia spp. Tunisia, a North African country located on the Mediterranean border, covering ∼165 000 km2, harbors several types of saline habitats and biotopes where halophytes preferably vegetate. With ∼6000 worldwide and over 420 Tunisian species, halophytes represent a huge potential in several fields, including desalination, phytoremediation, agrofarming, medicinal use, industrial applications, pharmacology and even nanotechnology. We describe the practical and technical steps followed and bioinformatics tools used to conceive and design the first Tunisian halophytes database, enabling species identification and characterization. As a first version, information about botany, morphology, ecophysiology and biochemistry were provided for the identified species with their sites of growing in Tunisia, first step of biodiversity conservation, management and valorization. The database will be regularly maintained, updated and enriched to achieve the goal of whole Tunisian halophyte species and fit the needs of scientists and all category of users.Database URL: http://halophytes.rnrt.tn/

Screening, characterisation and bioactivities of green fabricated TiO2 NP via cyanobacterial extract.

The present study was aimed at exploring 37 strains of cyanobacteria for the biofabrication of TiO2 NP and evaluation of their antioxidant, antifungal, antibacterial and hemolytic activity. Screening of cyanobacterial strains was done via SEM, followed by optimisation and characterisation of the best strain. Synechocystis NCCU-370 appeared as the best strain for the synthesis of TiO2 NP in terms of size (73.39nm) and time (24h) after screening. Following optimisation, nanoparticles were synthesised in 12h having an average grain size of 16nm. The aqueous extract preparation required heating of 5mg/ml of powdered biomass to 60°C for 10min. Optimum conditions for the synthesis of TiO2 NP were found to be pH 7, 30°C and 12-h cell extract exposure to 0.1mM of salt. Antioxidant activity was evaluated via DPPH, ABTS and FRAP assay. Antifungal potential was explored against Candida albicans (MIC = 125µg/ml), Candida glabrata (MIC = 500µg/ml) and Candida tropicalis (MIC = 250µg/ml), whereas antibacterial potential was gauged for Bacillus cereus (MIC = 31.25µg/ml), Escherichia coli (MIC = 31.25µg/ml) and Klebsiella pneumoniae (MIC = 500µg/ml) strains. Biogenic TiO2 NP demonstrated partial synergistic effect and excellent biocompatibility.

Mechanism of high affinity potassium transporter (HKT) towards improved crop productivity in saline agricultural lands.

Glycophytic plants are susceptible to salinity and their growth is hampered in more than 40mM of salt. Salinity not only affects crop yield but also limits available land for farming by decreasing its fertility. Presence of distinct traits in response to environmental conditions might result in evolutionary adaptations. A better understanding of salinity tolerance through a comprehensive study of how Na+ is transported will help in the development of plants with improved salinity tolerance and might lead to increased yield of crops growing in strenuous environment. Ion transporters play pivotal role in salt homeostasis and maintain low cytotoxic effect in the cell. High-affinity potassium transporters are the critical class of integral membrane proteins found in plants. It mainly functions to remove excess Na+ from the transpiration stream to prevent sodium toxicity in the salt-sensitive shoot and leaf tissues. However, there are large number of HKT proteins expressed in plants, and it is possible that these members perform in a wide range of functions. Understanding their mechanism and functions will aid in further manipulation and genetic transformation of different crops. This review focuses on current knowledge of ion selectivity and molecular mechanisms controlling HKT gene expression. The current review highlights the mechanism of different HKT transporters from different plant sources and how this knowledge could prove as a valuable tool to improve crop productivity.

Evaluation of synergistic effects of coupling capacitive deionization (CDI) and UV oxidation processes for saline water treatment

In the present study, the synergistic effects of capacitive deionization (CDI) and ultraviolet (UV) based advanced oxidation process (AOP) have been investigated for the simultaneous removal of NaCl salt and humic acid (HA), by an organic contaminant approach. A specific CDI rod geometry setup was utilized to allow for direct UV irradiation on the electrodes’ surface during CDI experiments. The characteristics of the coated electrodes were examined by scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS). The results of desalination experiments showed that the maximum salt adsorption capacity (mSAC) and salt removal efficiency were 3.96 mg/g and 52.5%, respectively under constant operating conditions (i.e., an applied voltage of 1.2 V and an initial salt concentration of 20 mM). Also, experiments involving simultaneous removal of salt and organic contaminant, demonstrated that the presence of HA in water has little impact on the desalination efficiency. After combining CDI and AOP under constant operating conditions (i.e., an applied voltage of 1.2 V, UV irradiation with a fluence rate of 6.8 mW/cm2, and initial concentrations of 20 mM of salt and 10 ppm of HA), the HA removal efficiencies in the charge and discharge reservoirs were 76.0% and 75.4%, respectively after 200 min of experimental time.

Effect of salinity stress on quinoa germination. Influence of ionic and osmotic components

Quinoa is a salinity tolerant species that can be used as a complementary crop in saline soils in many parts of the world. Previous studies, mostly referred to the influence of sodium chloride, have shown that according to the genetic material there are different salinity degrees of tolerance. In general, germination decreases with increasing salinity. However, there are few quinoa studies related to the components of saline stress (ionic and osmotic factors). In this study, the influence of both factors, in the presence of NaCl and KCl salts on CICA Var cultivated in the Argentina Northwest was evaluated. The seeds were germinated under different salt concentrations (0, 100, 200, 300, 400 mM NaCl and KCl) and in PEG8000 in solutions osmotically equivalent to the concentrations of sodium and potassium salts. The results showed that up to 200 mM of NaCl and KCl, germination reached values higher than 90% and after 300 mM of salts the rate and final germination decreased. The ionic factor of both salts has the greatest influence on germination. This result can be explained by the physiological adjustment that this variety, originally from the mountainous area of Peru, displayed against the edaphic and microclimatic conditions of the cultivation site in the Argentine Northwest (1,995 m asl).

Priming Induction in Neighbouring Plants of Gossypium hirsutum under Salt Stress

Plants are subjected to various types of environmental stresses throughout their lifecycle. It has been found that plants are able to communicate with the neighbouring plants under stress conditions through volatile organic compounds. These volatiles act as signals for the neighbouring plants thus preparing them for the upcoming stress, a phenomenon known as priming. So, the present study explores the effects of salt stress on cotton plants and the resultant induction of priming in the nearby plants. For this purpose, salt tolerant cotton (Gossypium hirsutum) variety was used. Two concentration levels, 100 mM, and 150 mM of salt were used to study the impacts of the stress. The experiment was divided into two steps for each treatment. In the first step, a set of plants (emitters) was given salt stress. The second set of plants (receivers) was placed adjacent to the stressed plants (emitters), while the third set of plants was placed separately as a control for both the treatments. Various physiological and morphological parameters were measured at the beginning and the end of the first step. In the second step, the receiver plants now termed as "primed" were given the same levels of stress while a new set of non-primed plants was placed near the primed plants. These non-primed plants were now treated with 100mM and 150mM of NaCl respectively and the results were compared. The results show that plants were able to get signals from neighbouring stressed plants. Plants responded by altering morphology and physiology to prepare themselves for future stress conditions.

Mechanisms by Which Salt Concentration Moderates the Dynamics of Human Serum Transferrin.

The dynamical and thermodynamic behavior of human transferrin (hTf) protein in saline aqueous solution of various concentrations is studied. hTf is an essential transport protein circulating iron in the blood and delivering it to tissues. It displays highly pH dependent cooperativity between the two lobes, each carrying an iron, and forms a tight complex with the receptor during endocytosis, eventually recycled to the serum after iron release. Molecular dynamics simulations are used to investigate the effects of the amount of salt on protein conformation and dynamics to analyze the structure-function relationship in free hTf at serum pH. To monitor the ionic strength dependence, four different ionic concentrations, 0, 50, 130, and 210 mM NaCl for two protonation states of the iron coordination site is considered. Two mechanisms by which salt affects hTf are disclosed. In the totally closed state where iron coordinating tyrosines are deprotonated, the addition of even 50 mM of salt alters the electrostatic potential distribution around the protein, opening energetic pathways for tyrosine protonation from nearby charged residues as a required first step for iron release. Once domain opening is observed, conformational plasticity renders the iron binding site more accessible by the solvent. At this second stage of iron release, R124 in the N-lobe is identified as kinetically significant anion binding site that accommodates chloride ions and allosterically communicates with the iron binding residues. Opening motions are maximized at 150 mM IS in the N-lobe, and at 210 mM in the C-lobe. The extra mobility in the latter is thought to preclude binding of hTf to its receptor. Thus, the physiological IS is optimal for exposing iron for release from hTf. However, the calculated binding affinities of iron show that even in the most open conformations, iron dissociation needs to be accompanied by chelators.

Effect of Nano Chitosan on Growth, Physiological and Biochemical Parameters of Phaseolus vulgaris under Salt Stress

Salt stress is one of the abiotic stresses; it is a major factor which reduces crop productivity. Nano particles have become a pioneer material in agriculture research nowadays because they have unique physicochemical properties. This study aimed to investigate the effects of chitosan nanoparticles on germination and seedling growth parameters under salt stress condition for bean plant (Phaseolus vulgaris L). Moreover the effect of nano chitosan combined with selected concentration of salinity (100mM NaCl) on germination and vegetative growth was also examined. Different concentrations of salinity (50 mM, 100 mM and 150 mM NaCl) was used. Data indicated that salinity decreased salt tolerance index S.T.I of germination percentage as well as seedling growth. The bad effect was higher in 150 mM concentration; so the second experiment was continued with the 100 mM NaCl concentration. The treatment of bean plantwith 100 mM of salt combined with different concentration of nano chitosan (0.1%, 0.2% and 0.3%) indicated that nano chitosan in all concentrations significantly promoted seed germination and radical length under salt stress. The best treatment on germination was 0.3 % of nano chitosan. Growth variables (plant height, leaf area, fresh and dry weights of the shoot and root) were increased significantly. High significant increase in both M.S.I and Chl.a, similarly , catalase , proline, RWC, Chl.b , caroteniods and antioxident enzymes showed positive eefect at 0.1% concentrarion.

Study of the Effect of Salt Stress on Biometric Characteristics of Barley: Hordeum Vulgare L. (Poaceae)

The aim of our work is to study the response of the barley plant (Hordeum vulgare L.) to salt stress, at different NaCl concentrations (0, 50, 100, 150 and 250 mM) and follow its growth over time in the effect of salt stress . The control is based mainly on measurements of biometric parameters: length of the aerial and underground parts, fresh biomass, dry biomass and leaf area. The results clearly show the influence of salt stress on these parameters. The variety of barley, studied, showed good resistance to the phenomenon at concentrations not exceeding 150 mM salt. The study of the variance of the different parameters with ANOVA revealed no significant differences in the length of the ground aerial part and fresh biomass variations, the latter is very highly significant at a concentration greater than 150 mM of salt. Dry biomass showed no significance for concentrations less than 150 mM, while it is very highly significant for 250 mM NaCl. With regard to the leaf surface, the variations are significant for less than 100 mM and very highly significant beyond 250 mM of salt. 

Exogenous application of free polyamines enhance salt tolerance of pistachio (Pistacia vera L.) seedlings

The protective effects of free polyamines (PAs) against salinity stress were investigated for pistachio seedlings (Pistacia vera cv. Badami-Zarand) in a controlled greenhouse. Seedlings were treated with 25, 50, 100 and 150 mM of salts including NaCl, CaCl2 and MgCl2. Foliar treatments of putrescine, spermidine (Spd) and spermine (Spm) (0.1 and 1 mM) were applied during the salinity period. Results showed that growth characteristics of pistachio seedlings decreased under salinity stress and the application of PAs efficiently reduced the adverse effects of salt stress. PAs reduced the severe effects of salt stress in pistachio seedlings neither by increasing the activities of peroxidase and ascorbate peroxidase nor by increasing the proline content but by increasing the activities of superoxide dismutase and catalase and decreasing the hydrogen peroxide (H2O2) activity. PAs treated seedlings showed a lower Na+:K+ ratio and Cl− in leaves suggesting the role of PAs in balancing the ion exchange and better Na+:K+ discrimination under salt stress condition. These results showed the promising potential use of PAs especially Spm and Spd for reducing the negative effects of salinity stress and improving the growth of pistachio seedlings.

Potential probioticLactobacillus strains for piglets from an arid coast

Important centres for the pork industry have become growth in arid regions in the world and pig production needs alternatives to increase the productivity. A screening of predominantLactobacillus strains from healthy piglets was performed in order to select specific probiotics. The ability of 164 strains to grow at different temperatures and concentrations of NaCl was evaluated. Results showed that all of them grew at 45 °C, 75% at 50 °C and 64% resisted 680 mM of salt. Adhesion to mucus and gastric mucin was evaluated showing 45% of strains isolated from faeces were able to adhere whereas 71% of strains from mucus showed mucus binding activity. Among the 164 isolates, 27 adhesive strains were identified using comparisons with 16S rDNA and intergenic 16-23S sequences. Results indicated thatL. fermentum andL. reuteri were the most common species in faeces and mucus, respectively. Ability to grow in gastrointestinal mucus was evaluated showing that 92.6% of strains were able to replicate. Additionally, bacterial strain grown in 3.5% MRS with bile salts was evaluated. These results indicated that animals inhabiting isolated arid coasts are a rich source of probiotics, which resist adverse environmental conditions and can colonise the intestinal tract of pigs.

Biochromatographic framework for analyzing magnesium chloride salt dependence on nor-NOHA binding to arginase enzyme

Our group demonstrated recently that arginase I inhibition reduces endothelial dysfunction and blood pressure rising in spontaneously hypertensive rats [C. Demougeot, A. Prigent-Tessier, C. Marie, A. Berthelot, J. Hypertens. 23 (2005) 971; C. Demougeot, A. Prigent-Tessier, T. Bagnost, C. Andre, Y. Guillaume, M. Bouhaddi, C. Marie, A. Berthelot, Life Sci. 80 (2007) 1128]. This discovery opens interesting perspectives in the development of new drugs against hypertension. As well, in a previous paper [T. Bagnost, Y.C. Guillaume, M. Thomassin, J.F. Robert, A. Berthelot, A. Xicluna, C. Andre, J. Chromatogr. B: Analyt. Technol. Biomed. Life Sci. 856 (2007) 113], a novel biochromatographic column was developed in our laboratory for studying the binding of N ω-hydroxy-nor- l-arginine (nor-NOHA), an arginase inhibitor, with this enzyme. In this manuscript, using this novel biochromatographic concept, the effect of magnesium chloride on the nor-NOHA/arginase binding was analyzed for the first time. This study demonstrated that the salt ions interacted with arginase and played a great role in the nor-NOHA/arginase association. For a salt concentration ( x) in the medium less than 3 mM, the nor-NOHA/arginase binding decreased with x due to a decrease of the charge–charge interactions between nor-NOHA and its arginase binding site. Above 3 mM of salt in the medium, the affinity of nor-NOHA to arginase increased slightly with x because the net number of ions ( n) (Mg 2+ or Cl −) released or bound upon complex formation is low. As well, it was clearly demonstrated, that above 3 mM the n value depend on the salt concentration in the bulk solvent and was approximately nil for x = 12 mM. This dependence was due to a gradual and conformational change of the arginase enzyme which around 12 mM adopted a less flexible structure; its binding site was thus less accessible to nor-NOHA and nor-NOHA–arginase association decreased slightly.

Arbuscular-Mycorrhizal Contributes to Alleviation of Salt Damage in Cassava Clones

ABSTRACT This study determined how arbuscular-mycorrhizal (AM) colonization by Glomus intraradices affected plant biomass and salt tolerance (in terms of growth) of three cassava clones (SOM-1, 05, and 50). Survival, root, stem and leaf production, and nutrient accumulation were determined in AM-inoculated and non-inoculated cassava clones under a range of sodium chloride (NaCl) levels (0, 68.4, or 136.8 mM) in the medium. The AM colonization stimulated plant growth and increased survival at 136.8 mM of salt. Clone SOM-1 showed to be the most salt tolerant of the three clones tested. G. intraradices-inoculation was important not only for growth promotion, but also played a crucial role in protecting cassava clones against salt (particularly the most salt sensitive clones). Mycorrhizal clones growing under 136.8 mM of NaCl showed greater dry weight than non-mycorrhizal clones growing without salt. Results show that AM-colonization provides a biological mechanism by which cassava clones increased plant biomass and salt tolerance being required for the best cassava clone development under non-stress and stress conditions.

Quantitative measurements of C-reactive protein using silicon nanowire arrays

A silicon nanowire-based sensor for biological application showed highly desirable electrical responses to either pH changes or receptor-ligand interactions such as protein disease markers, viruses, and DNA hybridization. Furthermore, because the silicon nanowire can display results in real-time, it may possess superior characteristics for biosensing than those demonstrated in previously studied methods. However, despite its promising potential and advantages, certain process-related limitations of the device, due to its size and material characteristics, need to be addressed. In this article, we suggest possible solutions. We fabricated silicon nanowire using a top-down and low cost micromachining method, and evaluate the sensing of molecules after transfer and surface modifications. Our newly designed method can be used to attach highly ordered nanowires to various substrates, to form a nanowire array device, which needs to follow a series of repetitive steps in conventional fabrication technology based on a vapor-liquid-solid (VLS) method. For evaluation, we demonstrated that our newly fabricated silicon nanowire arrays could detect pH changes as well as streptavidin-biotin binding events. As well as the initial proof-of-principle studies, C-reactive protein binding was measured: electrical signals were changed in a linear fashion with the concentration (1 fM to 1 nM) in PBS containing 1.37 mM of salts. Finally, to address the effects of Debye length, silicon nanowires coupled with antigen proteins underwent electrical signal changes as the salt concentration changed.

Behaviour of antioxidant defense system in the adaptive response to salt stress in Helianthus annuus L. cells

A relationship between the antioxidant defense system and salt tolerance in two types of sunflower calli differing in salt sensitivity was studied. No reduction in growth occurred in the NaCl-salt-adapted cell line (T) when grown on 175 mM NaCl but growth of the salt-stressed cell line (S) was reduced by 83%. Lipid peroxidation and protein oxidation increased during acute stress of salt stressed cells at 14 and 28 d of the experiment, while salt-adapted calli (T) remained similar to non-shocked (C) values. The antioxidant defense system of callus adapted to growth under NaCl responded differently to 175 mM of salt compared with the corresponding controls under shock treatment. Salt-adapted and salt-stressed calli showed a similar pattern in GSH content at day 14 but at day 28 in S calli, GSH content was increased 100% over the non-shocked calli, while T calli returned to the initial values. In the salt-stressed calli, a general decrease in all the antioxidant enzymes studied (except for glutathione reductase and dehydroascorbate reductase activities) was observed at day 28. Except for catalase, the antioxidant enzymes were elevated constitutively in adapted calli as compared to stressed cells, when both were grown in the absence of NaCl (time 0), and remained unaltered until 28 d after the beginning of the experiment. These results suggest the involvement of an enzymatic antioxidant defense system in the adaptive response to salt stress in Helianthus annuus L. cells.

A modified diffuse reflectance infrared Fourier transform spectroscopy cell for depth profiling of ceramic fibers

A modified diffused reflectance infrared Fourier transformed spectroscopy (DRIFTS) accessory was used to analyze the surface properties of alumino–silicate fibers. The modifications are simple and involve a different way of performing depth-profiling from traditional DRIFTS by removing ∼2 mm of salt from a full cup prior to placing the sample in for depth profiling. This method proved successful in elucidating the effects of quenching alumino–silicate fibers in mineral oil versus quenching in an air stream.

Preferential interactions in the H 2O/lysozyme/AlCl 3 system

The preferential interactions of lysozyme with solvent components is studied in aqueous solutions of AlCl 3. The interaction parameter is negative at large salt concentrations, indicating that the interaction process of both salt and protein is thermodynamically favorable. The transfer free-energy parameter and the solubility data show that aluminum chloride is a salting-in agent for lysozyme. Moreover, these preferential interactions also are correlated with both protein solubility in the solvent medium and the influence of salt on the lysozyme structure. Viscometric and refractometric studies show that lysozyme can undergo a conformational change at 1 mM of salt, and spectrophotometric studies indicate a protein activity of approximately 75% at 10 mM of salt. Therefore, neither the interaction of AlCl 3 with the lysozyme nor the conformational change undergone directly affect the catalytic amino acid residues of the active site.