Low NaCl Concentrations Research Articles

Difference in calcium ion precipitation between free and immobilized Halovibrio mesolongii HMY2

Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional methods. However, the low sodium chloride (NaCl)-tolerance of bacteria limits applications to only water with low NaCl concentrations. Here, calcium ions in hypersaline wastewater (10% NaCl) were precipitated by free and immobilized Halovibrio mesolongii HMY2 bacteria and the differences between them were determined. The results show that calcium ions can be transformed into several types of calcium carbonate with a range of morphologies, abundant organic functional groups (C-H, C-O-C, C=O, etc), protein secondary structures (β-sheet, α-helix, 310 helix, and β-turn), P=O and S-H indicated by P2p and S2p, and more negative δ13CPDB (‰) values (-16.8‰ to -18.4‰). The optimal conditions for the immobilized bacteria were determined by doing experiments with six factors and five levels and using response surface method. Under the action of two groups of immobilized bacteria prepared under the optimal conditions, by the 10th day, Ca2+ ion precipitation ratios had increased to 79%-89% and 80%-88% with changes in magnesium ion cencentrations. Magnesium ions can significantly inhibit the calcium ion precipitation, and this inhibitory effect can be decreased under the action of immobilized bacteria. Minerals induced by immobilized bacteria always aggregated together, had higher contents of Mg, P, and S, lower stable carbon isotope values and less well-developed protein secondary structures. This study demonstrates an economic and eco-friendly method for recycling calcium ions in hypersaline wastewater, providing an easy step in the process of desalination.

Alkaline Salt Inhibits Seed Germination and Seedling Growth of Canola More Than Neutral Salt.

Salinity is a major constraint to crop growth and productivity, limiting sustainable agriculture production. Planting canola (Brassica napus L.) variety with salinity-alkalinity tolerance as a green manure on the large area of salinity-affected land in Xinjiang could alleviate feed shortage. To investigate the differential effects of neutral and alkaline salt stress on seed germination and seedling growth of canola, we used two salts at varying concentrations, i.e., NaCl (neutral salt at 100, 150, and 200 mM) and Na2CO3 (alkaline salt at 20, 30, and 40 mM). To further explore the effects of Na+ and pH on seed germination, we included combined of NaCl (0, 100, 150, and 200 mM) and pH (7.1, 8.0, 9.0, 10.0, and 11.0). Shoot growth was promoted by low concentrations of NaCl and Na2CO3 but inhibited at high salt concentrations. Given the same Na+ concentration, Na2CO3 inhibited seed germination and seedling growth more than NaCl. The results showed that the main factor affecting seed germination and seedling growth is not pH alone, but the interaction between pH and salt ions. Under NaCl stress, canola increased the absorption of K+, Ca2+, and Mg2+ in roots and K+ in leaves. However, under Na2CO3 stress, canola maintained a high K+ concentration and K+/Na+ ratio in leaves and increased Ca2+ and Mg2+ in roots. Our study showed that alkaline salts inhibit canola seed germination and seedling growth more significantly than neutral salts and salt species, salt concentration, and pH significantly affected on seed germination and seedling growth. However, pH affected seed germination and seedling growth mainly through an interaction with salt ions.

Experimental Investigation and Numerical Simulation for Corrosion Rate of Amorphous/Nano-Crystalline Coating Influenced by Temperatures.

A high-velocity oxygen fuel (HVOF) system was employed to prepare a Fe49.7Cr18Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 amorphous coating on mild steel. The electrochemical behavior of the resultant coatings, namely as-sprayed coating and vacuum heat-treated coating (at 650 °C and 800 °C), were investigated in a 3.5% NaCl solution at variable temperatures using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, optical microscopy (OM), and XRD diffraction. Moreover, COMSOL Multiphysics version 5.5 software were employed for predicting the galvanic corrosion of amorphous material immersed in an aqueous NaCl solution, using the software finite element kit. The experiments demonstrated that the coatings’ pitting resistance was significantly affected by temperature. The results also showed that temperature affected the pitting corrosion rate and changed the shape of the pits. However, the changes were not as extreme as those observed in stainless steel. Furthermore, there was no significant difference between the as-sprayed coating and the vacuum-heat-treated coating at 650 °C. At low NaCl concentrations at and temperatures below the critical pitting temperature, the resulting pits were significantly small with a hemisphere-like. By contrast, at a higher NaCl concentration at 70 °C, particularly in the case of heating at 650 °C, the pits appearing on the Fe-based amorphous coating were vast and sometimes featured a lacy cover.

Co-culturing Hyphomicrobium nitrativorans strain NL23 and Methylophaga nitratireducenticrescens strain JAM1 allows sustainable denitrifying activities under marine conditions.

BackgroundHyphomicrobium nitrativorans strain NL23 and Methylophaga nitratireducenticrescens strain JAM1 are the principal bacteria involved in the denitrifying activities of a methanol-fed, fluidized-bed marine denitrification system. Strain NL23 possesses the complete denitrification pathway, but cannot grow under marine conditions in pure cultures. Strain JAM1 is a marine bacterium that lacks genes encoding a dissimilatory nitrite (NO2−) reductase and therefore cannot reduce NO2−. Here, we report the characterization of some of their physiological traits that could influence their co-habitation. We also perform co-cultures to assess the potential synergy between the two strains under marine and denitrifying conditions.MethodologyAnoxic planktonic pure cultures of both strains were grown with different concentrations of nitrate (NO3−). Anoxic planktonic co-cultures could only be cultured on low NaCl concentrations for strain NL23 to grow. Biofilm co-cultures were achieved in a 500-mL bioreactor, and operated under denitrifying conditions with increasing concentrations of NaCl. NO3− and NO2− concentrations and the protein content were measured to derive the denitrification rates. The concentrations of both strains in co-cultures were determined by quantitative PCR (qPCR). Ectoine concentration was measured by mass spectrometry in the biofilm co-culture. The biofilm was visualized by fluorescence in situ hybridization. Reverse-transcription-qPCR and RNA-seq approaches were used to assess changes in the expression profiles of genes involved in the nitrogen pathways in the biofilm cultures.ResultsPlanktonic pure cultures of strain JAM1 had a readiness to reduce NO3− with no lag phase for growth in contrast to pure cultures of strain NL23, which had a 2-3 days lag phase before NO3− starts to be consumed and growth to occur. Compared to strain NL23, strain JAM1 has a higher µmax for growth and higher specific NO3− reduction rates. Denitrification rates were twice higher in the planktonic co-cultures than those measured in strain NL23 pure cultures. The biofilm co-cultures showed sustained denitrifying activities and surface colonization by both strains under marine conditions. Increase in ectoine concentrations was observed in the biofilm co-culture with the increase of NaCl concentrations. Changes in the relative transcript levels were observed in the biofilm culture with genes encoding NapA and NapGH in strain NL23. The type of medium had a great impact on the expression of genes involved in the N-assimilation pathways in both strains.ConclusionsThese results illustrate the capacity of both strains to act together in performing sustainable denitrifying activities under marine conditions. Although strain JAM1 did not contribute in better specific denitrifying activities in the biofilm co-cultures, its presence helped strain NL23 to acclimate to medium with NaCl concentrations >1.0%.

Isolation, biochemical characterization, and development of a biodegradable antimicrobial film from Cirrhinus mrigala scale collagen.

Collagen is a promising candidate for food and pharmaceutical applications due to its excellent biocompatibility, low antigenicity, and controlled biodegradability; however, its heavy price restricts its utilization. Fish scales generated during the processing are generally regarded as waste material and an environmental pollutant, though they are a promising source of collagen. In the present study, Cirrhinus mrigala scales were demineralized and extracted for acid-soluble collagen (ASC) using acetic acid, with a collagen yield of 2.7%. UV-Vis spectra, SDS-PAGE, FTIR analyses, and amino acid composition confirmed the type I nature of the collagen extracted. The denaturation temperature of the collagen was found to be 30.09 °C using differential scanning calorimetry (DSC). The collagen was highly soluble at acidic pH and lower NaCl concentrations while its solubility was lowered in alkaline conditions and NaCl concentrations above 0.5M. The collagen exhibited good emulsifying potential with an emulsion activity index (EAI) and emulsion stability index (ESI) of 21.49 ± 0.22 m2g-1 and 15.67 ± 0.13min, respectively. Owing to the good physicochemical characteristics of the extracted collagen, collagen-chitosan-neem extract (CCN) films were prepared subsequently which showed good antimicrobial activity against Bacillus subtilis NCIM 2635, Staphylococcus aureus NCIM 2654, Escherichia coli NCIM 2832, and Pseudomonas aeruginosa NCIM 5032, suggesting the potential of collagen in the development of antimicrobial films. These results demonstrate that the collagen from fish waste could be valorized and used effectively along with chitosan and neem extract for the synthesis of novel biodegradable films with antimicrobial efficacy.

Effect of electrolyte on the surface dilational rheological properties of branched cationic surfactant

The studies of surface dilational rheology are important to detent the nature of adsorption film and the properties of foam. In this paper, the adsorption and dilational rheological properties of branched cationic surfactant hexadecanol polyoxyethylene(3) glycidyl ether ammonium chloride (C16G(EO)3PC) at the air-water interface in the absence and presence of electrolyte (NaCl) were investigated by drop shape analysis. The results show that the surface adsorption layer of C16G(EO)3PC behaves elastic in nature with high value up to 90 mN/m, which indicates that the slow relaxation process plays a main role because of the re-arrangement of long branched alkyl chain. The addition of NaCl will enhance diffusion-exchange process and accelerate the formation of film and decreases dilational elasticity obviously. At low NaCl concentration, the in-film slow relaxation process dominates the nature of film, dilational viscosity decreases with an increase of oscillating frequency. By adding more NaCl, diffusion-exchange process plays the crucial role and dilational viscosity increase as a function of frequency. Moreover, viscosity at high NaCl concentration shows larger value under higher oscillating frequency, indicating the contributions of fast diffusion-exchange process. The elastic adsorption film becomes to be viscoelastic by adding electrolyte.

Use of Reverse Electrodialysis to Harvest Salinity Gradient Energy from Oilfield Produced Water

Two lab-scale electrodialysis (RED) stacks with different intermembrane spacing were used in this study. Each stack consists of two membrane pairs. Thick intermembrane spacing stack was made of four identical plexiglass sections, with outer dimensions 5 cm * 5 cm * 1.5 cm and an inner cross-section of 3 cm diameter each to construct two diluted solution compartments and two concentrated solution compartments. For the thin intermembrane spacing configuration, four rubber spacers with a thickness of 1 mm and an inner opening of 3 cm each were used instead of these sections. Two copper sheets were used as anode and cathode electrodes. Different solutions with NaCl concentrations of 15,000, 30,000 and 200,000 mg/l were used as a concentrated solution and different solutions with relatively low NaCl concentrations of 25, 1000 and 3600 mg/l were used as a diluted solution. A 30,000 mg/l NaCl solution was used as a diluted solution when the concentrated stream was with NaCl concentration of 200,000 mg/l. The electrode solution was of 15,000 mg/l (~0.25 M) NaCl and 8,000 mg/l (~0.05 M) CuSO4.5H2O. The results of this study confirmed the validity of using RED technology to harvest energy from salinity gradient using saline and freshwater available abundantly particularly in Iraq. An experiment on a synthetic hypersaline oil field co-produced water as a concentrated stream and seawater as a diluted stream showed that the system performance is reproducible and stable. A maximum power density of 0.029 W/m2 could be harvested.

Growth, Physiological, and Photosynthetic Responses of Xanthoceras sorbifolium Bunge Seedlings Under Various Degrees of Salinity.

Xanthoceras sorbifolium Bunge is priced for its medical and energetic values. The species also plays a key role in stabilizing ecologically fragile areas exposed to excess soil salinity. In this study, the effects of salinity on the growth, physiological, and photosynthetic parameters of X. sorbifolium Bunge were investigated. The X. sorbifolium seedlings were subjected to five salt treatments: 0 (control, CK), 70, 140, 210, and 280 mM of sodium chloride (NaCl) solutions. NaCl caused a decrease in plant height, specific leaf area, biomass, and root parameters. Leaf wilting and shedding and changes in root morphology, such as root length, root surface area, and root tips were observed. This study found that X. sorbifolium is tolerant to high salinity. Compared with the CK group, even if the concentration of NaCl was higher than 210 mM, the increase of the relative conductivity was also slow, while intercellular CO2 concentration had a similar trend. Moreover, NaCl stress caused an increase in the malondialdehyde (MDA), soluble proteins, and proline. Among the enzymes in the plant, the catalase (CAT) activity increases first and decreased with the increase in the intensity of NaCl stress, but the salt treatment had no significant effect on superoxide dismutase (SOD) activity. The peroxidase (POD) showed an increasing trend under salt stress. It was found that the photosynthesis of X. sorbifolium was notably impacted by saline stress. NaCl toxicity induced a noticeable influence on leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (E), and water use efficiency (Wue). As salt concentration increased, the content of chlorophyll decreased. It can be found that a low concentration of NaCl induced the increase of photosynthetic capacity but a high-intensity exposure to stress resulted in the reduction of photosynthetic efficiency and SOD activity, which had a positive correlation. In summary, salt-induced ionic stress primarily controlled root morphology, osmotic adjustment, and enzyme activities of salt-treated X. sorbifolium leaves, whereas the low salt load could, in fact, promote the growth of roots.

On how the corrosion behavior and the functions of Cu, Ni and Mo of the weathering steel in environments with different NaCl concentrations

The corrosion behavior of weathering steel in the environments with different NaCl concentrations was systematically investigated. The results indicated a decrease of corrosion resistance of steel as NaCl concentration increased. While, the weight gain rate in high concentration was lower than that in lower conditions, which was attributed to the inhibition on the diffusion of O2 caused by the residual NaCl solution. Cu, Ni and Mo can mutually promote the agglomeration process and improve the performance of the rust layer in low NaCl concentrations, which was severely inhibited in high NaCl concentrations, resulting in a loose rust layer.

Effect of γ-aminobutyric Acid on Phenolics Metabolism in Barley Seedlings under Low NaCl Treatment.

It has been revealed that high NaCl stress (>60 mmol L−1) induced phenolics accumulation in barley seedlings, with γ-aminobutyric acid (GABA) playing a key role. Interestingly, low NaCl stimulus (20 mmol L−1) enhancing phenolics synthesis and growth of barley seedlings was also reported recently. Hence, exogenous GABA and its bio-synthesis inhibitor 3-mercaptopropionic acid (3-MP) were applied to reveal the mechanism of GABA regulating phenolics metabolism in barley seedlings treated with 20 mmol L−1 NaCl. The contents of total phenolics and flavonoids significantly increased by 11.64% and 14.52% under NaCl, respectively. The addition of GABA further increased phenolics and flavonoids contents, especially for gallic acid, protocatechuic acid, caffeic acid, and quercetin, compared with NaCl treatment. Simultaneously, GABA increased the activities and mRNA levels of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and 4-coumalyl CoA ligase (4CL). The addition of 3-MP suppressed the above effects, except for increasing the protein levels of PAL, C4H, and 4CL. Low concentration of NaCl not only promoted growth, but also stimulated endogenous GABA metabolism to affect key enzymes activities and mRNA levels for phenolics synthesis in barley seedlings.

Unraveling the Modulation of Controlled Salinity Stress on Morphometric Traits, Mineral Profile, and Bioactive Metabolome Equilibrium in Hydroponic Basil

Salinity is a major concern in several ecosystems and has a significant impact on global agriculture. To increase the sustainability of horticultural food systems, better management and usage of saline water and soils need to be supported by knowledge of the crop-specific responses to tolerable levels of salinity. The aim of this work was to study the effects of mild salinity on morphological growth and development, leaf color, mineral composition, antioxidant activities, and phenolic profile of sweet basil (Ocimum basilicum L.). Plants grew in hydroponics and were exposed to three nutrient solutions (NSs) differing in the NaCl concentration (either 0, 20, or 40 mM). Inhibitory effects on leaf area, fresh yield, and shoot biomass were evident starting from the lowest NaCl concentration, and they became more severe and wide-ranging at 40 mM, also affecting height and root-to-shoot ratio. Salinity increased the nutritional quality in terms of antioxidant activity and polyphenols in leaves, with a reduction in macroelements at 40 mM NaCl. Moreover, the two mild NaCl concentrations specifically modified the concentration of various phenolic acids in leaves. Overall, the use of a slightly saline (20 mM) NS could be tolerated by basil in hydroponics, strongly ameliorating the nutritional profile in the face of relative yield loss. Considering the significantly higher accumulation of bioactive compounds, our work implies that the use of low-salinity water can sustainably increase the nutritional value and the health-promoting features of basil leaves.

Characterization of clay-stabilized, oil-in-water Pickering emulsion for potential conformance control in high-salinity, high-temperature reservoirs

In this study, a Na-montmorillonite clay-stabilized, oil-in-water (O/W) Pickering emulsion system was prepared and tested under high-salinity and high-temperature conditions. The emulsifying ability of the clay particles, emulsion stability against creaming and coalescence, and emulsion rheological behavior at different NaCl concentrations and temperatures were investigated. The results showed that decane could be effectively emulsified by clay particles into small emulsion droplets at salinities up to 25 wt% NaCl. The emulsion had a relatively narrow drop size distribution. However, the emulsion stability against creaming decreased with increases in NaCl concentration. At low NaCl concentrations, clay particles connected with each other by edge-edge and edge-face interactions, forming a three-dimensional network that stabilized the emulsion against creaming. A higher concentration of NaCl caused some clay particles to connect through face-face interactions, forming clay clusters. At high NaCl concentrations, the temperature had only a slight effect on the emulsion stability against creaming. However, emulsion stability against coalescence decreased with increasing temperature due to increased droplet collision caused by Brownian motion. A higher concentration of NaCl moderated this temperature effect of coalescence. The viscosity of emulsion decreased with increased NaCl concentration. Temperature increases caused emulsion viscosity to decrease at low NaCl concentration conditions. When the NaCl concentration was higher than 10 wt%, the temperature had little effect on the viscosity. In summary, this study identifies an O/W Pickering system with the potential for conformance control in high-salinity and high-temperature reservoirs.

Effect of NaCl salinity stress on potato (Solanum tuberosum L.) plantlets grown and development under in vitro conditions

Salinity is one of the abiotic stresses that affect potato growth and productivity in mostly semi-arid and growing areas, causing an imbalance in the physiological processes of plants. The accumulation of Na+ and Cl- ions in cells is extremely toxic and can affect all of the plant mechanisms and enzymatic actions. . In vitro osmotic stress screening of plant genotypes is a useful tool that can be used instead of field trials and is based on osmotic stress tolerance. The major purpose of this work was to employ in vitro screening to reveal the variation in potato cultivars' salt stress tolerance Murashige and Skoog (MS) media supplemented with varied quantities of sodium chloride NaCl was used to culture stem cuttings consisting of a single node of various kinds ( 10 , 30 , 50,70,100 and 120 mM NaCl). Significant differences among treatments were noticed the highest concentration of NaCl gave the lowest values for most the study characters and there were significant differences among cultivars for the response of NaCl concentrations. Low concentrations of NaCl gave values close to the control treatment.

Preparation and characterization of a new family of bio-interpenetrating network hydrogel based on a green method

In this work, semi-interpenetrating polymer network hydrogels with and without castor oil (S-2IPN, S-3IPN, S-4IPN, S-2IPNC, S-3IPNC and S-4IPNC) are synthesized using a free-radical solution polymerization in presence of acrylic acid as a pH-responsive monomer and dimethyl aminoethyl methacrylate as a thermoresponsive monomer with carboxymethyl cellulose (CMC) as a cellulose derivative, potassium persulphate and N, N'-methylene bisacrylamide. Castor oil, as a green chemical material, is incorporated with a ratio (1:2) to CMC. The semi-interpenetrating network structures are formed and justifications are done by ATR-FTIR and Raman spectroscopy to assure their chemical composition. TGA, SEM, XRD and AFM approve thermogravimetric analysis, phase morphology, crystallinity and surface topography, respectively. The results show that the addition of castor oil enhances the texture and stability of hydrogels. It is concluded that S-IPNC hydrogels show higher swelling capacity than S-IPN hydrogels at lower NaCl concentration and pH range (5-7), due to increasing the osmotic pressure.Therefore, castor oil could be used as a green material in interpenetrating network hydrogels for water-saving applications.According to the principle of sustainable growth, environmentally biopolymer hydrogels pose a significant potential for using as water storage in the agricultural sector.

Comparative studies on the stress responses of two Bupleurum (Apiaceae) species in support of conservation programmes

Bupleurum tenuissimum is a rare species in Spain, which became extinct in recent decades in many localities, including protected areas. In the study area, the 'Albufera' Natural Park (SE Spain), the species was present in Limonietalia grasslands, a priority and endangered habitat, but has not been observed in the last 40 years. At present, it is included in conservation programmes aimed at its reintroduction in this territory. This study's primary objective was to establish the limits of tolerance of this species to salt and water stress under controlled greenhouse conditions. A congeneric species, B. fruticousm, was included as comparative material to get insights into its stress response mechanisms. Analysis of changes in growth parameters (stem length, number of leaves, root length, fresh weight and water content of roots and leaves) in response to the applied stress treatments confirmed that B. tenuissimum behaves as a facultative (moderate) halophyte susceptible to drought stress, whereas B. fruticosum is not severely affected by water stress but is sensitive to salinity, even at low NaCl concentrations. The stress-induced changes in several biochemical parameters (contents of photosynthetic pigments, ions, osmolytes, oxidative stress markers, and non-enzymatic antioxidant compounds, and specific activities of relevant antioxidant enzymes) explained the differential behaviour of the investigated Bupleurum species. In addition to the novelty of these findings in a genus that has rarely been studied from this perspective, these results will be relevant for implementing and managing B. tenuissimum conservation programmes, guiding the selection of reintroduction sites. The study also provides valuable information on the stress tolerance of B. fruticosum, with great potential for the ecological restoration of Mediterranean dry forest vegetation and riparian thickets.

Ion‐poor water and dietary salt deprivation upregulate the ghrelinergic system in the goldfish (Carassius auratus)

Because the ghrelinergic system in teleost fishes is broadly expressed in organs that regulate appetite as well as those that contribute to the regulation of salt and water balance, we hypothesized that manipulating salt and water balance in goldfish (Carassius auratus) would modulate the ghrelinergic system. Goldfish were acclimated to either freshwater (FW) or ion-poor FW (IPW) and were fed either a control diet containing 1% NaCl or low-salt diet containing 0.1% NaCl. Endpoints of salt and water balance, i.e., serum Na+ and Cl- levels, muscle moisture content and organ-specific Na+ -K+ -ATPase (NKA) activity, were examined in conjunction with brain, gill and gut mRNA abundance of preproghrelin and its receptor, growth hormone secretagogue receptor (ghs-r). Acclimation of fish to IPW reduced serum osmolality and Cl- levels and elevated kidney NKA activity, while FW fish fed a low NaCl diet exhibited a modest reduction in muscle moisture content but otherwise no apparent osmoregulatory disturbance. In contrast, a combined treatment of IPW acclimation and low dietary NaCl content reduced serum osmolality and Cl- levels, elevated muscle moisture content and increased gill, kidney and intestinal NKA activity. This intensified response to the combined effects of water and dietary ion deprivation is consistent with an increased effort to enhance ion acquisition. In association with these latter observations, a significant upregulation of preproghrelin mRNA expression in brain and gut was observed. A significant increase in ghs-r mRNAs was also observed in the gill of goldfish acclimated to IPW alone but a reduction in dietary NaCl content did not impact the ghrelinergic system of goldfish in FW. The results support the hypothesis that the ghrelinergic system is modulated in response to manipulated salt and water balance. Whether the central and peripheral ghrelinergic system contributes to ionic homeostasis in goldfish currently remains unclear and warrants further research.

Effects of osmotic stress on Chenopodium quinoa seed germination.

Quinoa is a pseudo-cereal native to the Andes known for its exceptional adaptation to extreme soil and climate conditions. The study of the response of Chenopodium quinoa to osmotic stress and the contribution to improving its yield aims to ensure production in arid and semi-arid regions as an alternative crop. The aim of this study is to test the germination capacity of 5 selected varieties; CQ-57, UDEC-2; ICBA-4, ICBA-5 and 115-R subjected to varying osmotic pressures using solutions of PEG-6000 and NaCl. Seeds are incubated at 25 °C for 10 days. Results showed that osmotic stress increases the lag phase but does not affect the germination rate at low concentrations of PEG and NaCl. While for high concentrations the germination rates decrease as compared to controls. Radicale and hypocotyl lengths decreased with increasing the degree of osmotic stress. The effects of osmotic stress are comparable in the 5 varieties. At high concentration of PEG or NaCl, ICBA-5 and CQ-57 exhibited the highest value of germination rate showing the capacity of these varieties to establish itself in regions suffering from salinity or water deficit.

Growth and Element Uptake by Salt-Sensitive Crops under Combined NaCl and Cd Stresses.

To test an assumption that organic soil can ameliorate nutritional disorders associated with metal and salinity stresses, we exposed salt-sensitive strawberry and lettuce to four salinity (0–60 mM NaCl) and three contamination (0.3–5 mg Cd/kg) rates in peat (pHH2O = 5.5). The results showed that, even at 20 mM NaCl, salinity stress exerted a dominant effect on rhizosphere biogeochemistry and physiological processes, inducing leaf-edge burns, chlorosis/necrosis, reducing vegetative growth in crops; at ≥40 mM, NaCl mortality was induced in strawberry. Signifiacntly decreased K/Na, Ca/Na and Mg/Na concentration ratios with raising salinity were confirmed in all tissues. The combined CdxNaCl stresses (vs. control) increased leaf Cd accumulation (up to 42-fold in lettuce and 23-fold in strawberry), whereas NaCl salinity increased the accumulation of Zn (>1.5-fold) and Cu (up to 1.2-fold) in leaves. Lettuce accumulated the toxic Cd concentration (up to 12.6 mg/kg) in leaves, suggesting the strong root-to-shoot transport of Cd. In strawberry Cd, concentration was similar (and sub-toxic) in fruits and leaves, 2.28 and 1.86 mg/kg, respectively, suggesting lower Cd root-to-shoot translocation, and similar Cd mobility in the xylem and phloem. Additionally, the accumulation of Cd in strawberry fruits was exacerbated at high NaCl exposure (60 mM) compared with lower NaCl concentrations. Thus, in salinized, slightly acidic and organically rich rhizosphere, pronounced organo- and/or chloro-complexation likely shifted metal biogeochemistry toward increased mobility and phytoavailability (with metal adsorption restricted due to Na+ oversaturation of the caton exchange complex in the substrate), confirming the importance of quality water and soils in avoiding abiotic stresses and producing non-contaminated food.

Inoculation with acetic acid bacteria improves the quality of natural green table olives

This study aims to develop a method for the preparation of natural table olives using locally selected microorganisms and without resorting to the usual techniques which employ lye treatment and acids. The effects of parameters, such as lye treatment, inoculation with yeasts, substitution of organic acids with vinegar and/or acetic acid bacteria, and finally alternating aeration have been assessed. Four different combinations were applied to the “Picholine marocaine” olive variety using indigenous strains, namely Lactobacillus plantarum S1, Saccharomyces cerevisiae LD01 and Acetobacter pasteurianus KU710511 (CV01) isolated respectively from olive brine, Bouslikhen dates and Cactus. Two control tests, referring to traditional and industrial processes, were used as references. Microbial and physicochemical tests showed that the L3V combination (inoculated with A. pasteurianus KU710511 and L. plantarum S1 under the optimal growth conditions of the Acetic Acid Bacteria (AAB) strain with 6% NaCl) was found to be favorable for the growth of the Lactic Acid Bacteria (LAB) strain which plays the key role in olive fermentation. This result was confirmed by sensory evaluation, placing L3V at the top of the evaluated samples, surpassing the industrial one where a chemical debittering treatment with lye was used. In addition, alternating aeration served to increase the microbial biomass of both AAB and LAB strains along with Saccharomyces cerevisiae LD01 strain, but also to use lower concentration of NaCl and to reduce the deterioration of olives compared to the anaerobic fermentation process. Finally, a mixed starter containing the three strains was prepared in a 10-L Lab-fermenter from the L3V sample in order to improve it in subsequent studies. The prepared starter mixture could be suitable for use as a parental strain to prepare table olives for artisan and industrial application in Morocco.

Conversion of xylose into furfural over MC-SnOx and NaCl catalysts in a biphasic system

Furfural is a promising platform chemical that can be catalyzed from lignocellulose biomass. In this study, a novel micro-mesoporous carbon supported tin oxide catalyst (MC-SnOx) was developed to convert xylose into furfural in a low sodium chloride (NaCl) concentration and acid-free biphasic system. The catalysts synthesized by annealing from 400 °C to 600 °C for 3.5h were characterized by BET, SEM, XPS, XRD, NH3-TPD and FTIR techniques. The factor that mostly affected the catalytic performance was the acid concentration of the catalysts, and the best catalytic performance was achieved by MC-SnOx annealed at 450 °C. Further increasing the annealing temperature can cause reduction, volatilization and aggregation of Sn species, which can finally affect acid concentration and performance of the catalyst. In addition, a synergistic catalytic effect was found between MC-SnOx and NaCl and effectivity of low concentration of NaCl indicated the potential of applying seawater or wastewater containing NaCl as a low-cost reaction solvent and NaCl source. To balance the catalytic performance, cost, equipment safety and environmental concerns, a reasonable furfural yield of 53.9% was achieved over the MC-SnOx-450 and NaCl (0.2 M) in biphasic system under mild conditions (180 °C and 20 min) with a good catalyst reusability.