Effects Of Different Salinities Research Articles

Effect of Different Salinities on the Biochemical Properties and Meat Quality of Adult Freshwater Drum (Aplodinotus grunniens) During Temporary Rearing.

Salinity is a significant environmental component that affects the physiological state of aquatic species. This study aimed to investigate whether water salinity had an impact on the biochemical properties and meat quality of adult Aplodinotus grunniens during temporary rearing of 7 days. Salinity caused increased osmotic pressure and antioxidant enzyme activities of Aplodinotus grunniens, which were attributed to the increase in the content of alanine and glutamate. It raised the hardness and shear force with an increase in salinity, leading to an increase in water-holding capacity. Salinity enhanced the DHA ratio with a decrease in the atherosclerotic index and thrombosis index. Combined with the increase in flavor amino acids and nucleotides, salinity enhanced the umami taste of Aplodinotus grunniens. These findings suggest that temporary rearing in salinity might be a practical approach to improving the meat quality of adult Aplodinotus grunniens.

Effects of Various Salinity and Water Stress Levels on Physiological and Biochemical Traits of Pepper

ABSTRACT Salinity and drought are among the most important abiotic stress factors with vital impacts on plant growth and development. Effects of different salinity and water stress levels on physiological and biochemical traits of pepper were investigated in this study. Five different salinity (S1: 0.3 dS/m; S2: 2.5 dS/m; S3: 5dS/m; S4: 7.5 dS/m; S5: 10 dS/m) and three different irrigation levels (I100: full irrigation; I75: 25% deficit; I50: 50% deficit) were used. Plant water consumption (ET) values decreased in increasing salinity levels. Pepper yield was significantly affected by both salinity and water stress. There was a 62.8% yield loss under salt stress as compared to the control treatment and a 70.1% yield loss under 50% water deficit (I50) as compared to full irrigation (I100). Irrigation water salinity and water deficits caused significant differences in physiological and photosynthetic parameters (plant height, plant fresh and dry weight, leaf area, chlorophyll, and carotenoid content). Salinity and water stress had significant impacts on enzymatic and non-enzymatic contents such as superoxide dismutase (SOD), peroxide (POD), catalase (CAT), proline, malondialdehyde (MDA), total phenolic content (TPC) and total flavonoid content (TFC). It was concluded based on present findings that irrigation waters with a salinity level up to 5 dS/m could be used in pepper cultivation, but water deficits should be avoided.

Histological analysis of Macrobrachium rosenbergii (de Man) eggs incubated in different salinities

Macrobrachium rosenbergii is the freshwater shrimp species of greatest economic interest, and its reproduction has been studied for commercial purposes. This study aimed to evaluate the effect of different salinities (0, 6, and 12 mg L-1) on the embryogenesis of this species. The females were observed daily according to their reproductive behavior. Upon the first sign of spawning, when their eggs were attached to the abdomen, they were collected for egg collection and transferred to the incubators at the respectively tested salinities. The eggs were collected every five days for up to 23 days, separated according to their stage of development, histologically processed, and stained for visualization of structural changes during embryogenesis using an optical microscope. From the egg's histological images at different embryonic development stages, the egg hatching time was evaluated, the changes that occurred in the eggs during embryogenesis, the total area of the eggs, the vacuole area, and the ratio between the vacuole area and the total area of the eggs. Differences were observed in hatching time, egg size, and vacuole area and area ratio. The 6 g L-1 of salinity treatment was statistically different from the other in all parameters analyzed. Therefore, it was concluded that 6 g L-1 of salinity positively influenced embryogenesis, as it presented hatches from the 15th day of embryogenesis, demonstrating that there was a greater speed of migration of vitellogenin for the formation of the embryo, accelerating embryogenesis and hatching of M. rosenbergii.

Influence of abiotic factors on the germination of an endemic sea lavender: First steps to shape local assemblage

Different Mediterranean sea lavender species, especially endemisms, appear within specific soil conditions led by vegetative trait syndromes. Nonetheless, seed traits contribute to functional structuring of plant communities, shaping the first stages of plant fitness and niche competition in stressful habitats. In this framework, we assess abiotic factors related to germination and establishment of Limonium tobarrense, an inland saltmarsh endemism located at the southeastern of the Iberian Peninsula, to shed light about the assembly processes in its early life stage. Experiments were performed to determine the effects of different salinities (0%, 0.5%, 1%, 1.5% and 2% NaCl) on seed germination under three combinations of day/night temperature (30 °C/20 °C, 25 °C/20 °C and 25 °C/15 °C) with a photoperiod of 12 h in light and 12 h in dark. Final germination percentage (FGP) and mean time-to-germinate (MTG) were studied after 30 days. The best FGP values were obtained in freshwater and low salinity conditions (1% and 1.5% NaCl). Moreover, similar MTG were observed at different salinities, but MTG was significantly high at lower temperature (i.e., 25 °C/15 °C). Finally, no differences between light conditions were observed. Our results suggest that salinity determines the germination and establishment of L. tobarrense, germinating successfully in freshwater and low salinity. In addition, a wide range of thermoperiod for its successful germination was found, although its interaction with the salinity was not significant. In consequence, L. tobarrense would germinate after the autumn rainfalls, when the salts are lixiviated in soil, and the medium temperature are favourable for the best seed germination conditions. Thus, specific environmental conditions would allow the own regeneration and adult niche of this endemism.

Growth and Oxidative Stress of Clownfish Amphiprion ocellaris Reared at Different Salinities

Aquaculture of ornamental marine fish is often conducted in recirculating aquaculture systems (RAS) using artificial seawater. Considering the cost of salts to produce artificial seawater (salinity 35‰), we investigated the effect of different salinities (5, 15, 25, and 35‰) on survival, growth, and oxidative stress responses of juvenile clownfish Amphiprion ocellaris. All fish died when reared at salinity 5‰, but at all other salinities survival was ≥95% in the other treatment groups. There was no influence of salinity on growth and oxidative stress responses of clownfish reared at salinities 15, 25, and 35‰, except for the activity of glutathione S-transferase (GST) of fish reared at 25‰, which was significantly lower compared to those reared in salinity 35‰. The salinity of home aquariums is usually 35‰, so even though clownfish can be reared in brackish water, they need to be transferred to full strength seawater (35‰) in order to be commercialized. Therefore, we also evaluated the responses of acute transference of fish reared at 15 to salinity 35‰. There were no mortalities associated with acute salinity transference and no oxidative damage was observed either. The total capacity against peroxyl radicals (ACAP) was immediately increased after fish were placed in salinity 35‰, and remained high after 168 h (7 days), helping fish to deal with oxidative threats. In conclusion, it is possible to rear juvenile clownfish at 15‰ without harming growth or inducing oxidative stress, possibly reducing costs of water salinization. They can be transferred from brackish water to salinity 35‰ immediately before going to the retail market, with no mortality or oxidative damage.

The Effects of Salinity on Growth of Sword Tail, <i>Xiphophorus helleri</i> (Heckel, 1848)

This study was conducted to evaluate effect of different salinities (0, 2, 4, 6 ppt) on growth and survival of sword tail, Xiphophorus helleri for 45 days. The species were taken from the water sources, which has the salinity of zero ppt in the experimental unit and then transferred to control and respective treatments(T1,2 ppt, T2, 4 ppt and T3, 6 ppt). Fifteen sword tail fish were placed in each aquarium (1.5x 1.0x 1.0 feet3). They were fed with commercial feed along with plankton up to satiation once in a day and individually weighed at an interval of 15 days. The highest final mean weight was recorded in T1 ( 1.17±0.09 mg) which was significantly (P<0.05) higher than control and other treatments. The final length of the sword tail reared in the control (4.45 ± 0.102 cm) and T1(4.45 ± 0.286 cm) was significantly different than other treatments T2(4.35 ±0.076 cm) and T3 (3.98 ± 0.119 cm). Survival was significantly different among the three salinity treatments (P<0.05). In conclusion, the species can grow well in water having the salinity of 2 ppt, but it can tolerate salinity of 6 ppt. These findings give us a lead to further upscale the study to understand the scope of culture of the ornamental species in saline affected areas.

Effect of Different Salinity on Osmolarity and Survival of Common Carp (Cyprinus carpio) with Fed Fermented Herbs

Giving fermented herbs feed can increase appetite, feed digestibility, growth, and fish health. Rearing fish in salinity media aims to find the best salinity levels for osmolarity and survival, so that fresh water fish can also be reared in saline waters. This study used an experimental method with a completely randomized design (CRD), 5 treatment levels 3 replications, namely P0(0 ppt), P1(3 ppt), P2(6 ppt), P3(9 ppt), and P4(12 ppt). Salinity treatment was made by diluting seawater (35‰) with fresh water. The test fish used were common carp measuring 6-8 cm, kept in an aquarium measuring 60x40x40cm with a stocking density of 1 fish/3 liters of water. The feed given was in the form of commercial pellets plus fermented herbs at a dose of 200 mL/kg of feed dissolved in 500 mL of clean water. This research was conducted for 60 days. The results showed that the osmolarity of carp for 60 days of rearing ranged from 135-332 mOsm/kg H2O The highest absolute weight growth in P2 with a value (10.52 g) and lowest at P4 (8.36 g). The highest survival rate of carp was in the P0, P1 and P2 with a value (100%), while in P3(95%) and P4(75%). Common carp are able to tolerate salinity levels up to 12 ppt.

Effect of different salinity on low permeability carbonate reservoir recovery using a new green polymeric nanocomposites

ABSTRACT Nanoparticles usage and altering mechanisms such as wettability alteration (CA) and interfacial tension (IFT) reduction in carbonate reservoirs are common methods used to recover more oil (nanoparticles-assisted enhanced oil recovery (EOR)) from these reservoirs. ZnO/SiO2/Xanthan as new nanocomposites were introduced at reservoir conditions and different salinity, and results were compared with commercial SiO2 nanoparticles in this study. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Brunauer-Emmett-Teller (BET) tests were used for observing morphology and the crystal structure of reservoir. Then, nanocomposites and SiO2 nanocomposites at 0.05 wt. % were used for seeing IFT and CA parameters at reservoir conditions and different salinity. It was found that nanocomposites have better results during IFT and CA tests compared to SiO2 nanoparticles, and nanocomposites were selected for surveying the salinity effect in the presence of nanocomposites on low permeability carbonate porous media with imbibition tests. CA (2 SW, 10 SW) decreased from (86 ̊, 80 ̊) to (79 ̊, 78 ̊) and (75 ̊, 74 ̊) in the presence of nanocomposites and SiO2, respectively, at 60°C and 1800 Psi. Two other important factors that were changed effectively in the presence of nanocomposites were IFT and stability tests. Nanocomposites show stable behavior at different salinity (ZP at 10 SW: 31.37, ZP at 2 SW: −28.00), and IFT decreased in the presence of 2 SW and 10 SW (higher in 2 SW). Finally, recovery factor was increased at both 2 SW and 10 SW in the presence of nanocomposites and reservoir conditions (2SW: 25.1%, 10 SW: 34.1%).

Effect of Salinity and Polycarboxylate Superplasticizer on Fresh Property of Seawater-Blended Cement.

The salinity of seawater can affect the properties of mixtures of polycarboxylate superplasticizer (PCE) and seawater. The purpose of this research is to study the effect of different salinities of water on the property of seawater-mixed cement slurry. Two PCE types with different side chain lengths and acid-ether ratios were used. Their physicochemical properties were explained by nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), turbidimetry, and dynamic light scattering (DLS) analysis. The performance of the PCEs was measured using slump, rheological energy, and solidification time. Finally, by measuring the adsorption volume, adsorption layer thickness, and water film thickness (WFT), the mechanisms involved in performance modification were studied. The results show that the workability and rheological performances of seawater-mixed cement paste are decreased by increasing salinity. With the increase in salinity, the minislump of the seawater-blended cement pastes with two PCEs decreased from 285 mm to 120 mm and from 280 mm to 78 mm, respectively, and the thixotropic areas were increased from less than 2000 Pa/s to above 10,000 Pa/s. Moreover, the adsorption amount of the two PCEs in the cement mixed with high-salinity seawater decreased by 55.99% and 71.56%, respectively, and the thickness of the adsorption layer and water film was decreased with increasing salinity. Compared with the two PCEs, PCE with long side chains and a high acid-ether ratio provided better salt resistance.

Effects of salinity on nitrite and elemental sulfur accumulation in a double short-cut sulfur autotrophic denitrification process

Double short-cut sulfur autotrophic denitrification (DSSADN) coupled with Anammox is of great significance in the low-carbon treatment of nitrogen-containing wastewater. In order to achieve high salinity autotrophic nitrogen removal, the effects of different salinities on the accumulation characteristics of NO2−-N and S0 and microorganisms in DSSADN process were studied. The results showed that the effect of salinity on the DSSADN process could be categorized into the stimulation, stable, and inhibition. When the salinity gradually increased to 2.5 %, the highest NO2−-N production rate (NiPR) and S0 production rate (S0PR) of DSSADN were 0.54 kg/(m3·d) and 1.1 kg/(m3·d) respectively. NiPR and S0PR gradually decreased as the salinity increased to more than 3 %. However, salinity had a relatively low impact on nitrite accumulation efficiency and S0 accumulation efficiency, which were 80 % and 81.5 %, respectively, when the salinity reached 5 %. Salinity has a great influence on the structure and abundance of microbial communities in the system.

A preliminary study on the effects of different salinities on some hormones level in serum of Yellow fin seabream Acanthopagrus latus fingerlings.

A laboratory experiment was performed on fingerlings of Acanthopagrus latus to estimate the effect of direct transfer from the controlled salinity 1.5 psu to different salinities of (1.5, 7.5, 15, 30 and 45 psu) for periods of (6, 24, 48 and 96) hrs. for short term effect experiments. The following hormones (cortisol, prolactin, thyroxin (T4) and triiodothyronine (T3)) were determined in the serum of these fishes by ELISA technique after exposed to different salinities. Results of T4 and T3 were correlated directly with salinity increase, the (96 hrs.) of time was not enough to reach the stable state of these hormones at all salinities. The salinity 45 psu gave the lowest level of T3 (0.468) ng/ml and showed a sharp drift of T4 level at the time 24 hrs. (0.368) μg/dl, which indicated a breaking down of these hormones, and A. latus fingerlings were unable to sustain at this salinity. Prolactin hormone was correlated inversely with the salinity increase which means that there was ability of this hormone to acclimate in freshwater. Cortisol level was high in high and low salinities indicating its activity in freshwater and seawater environments. The study concludes that the four hormones (cortisol, prolactin, T4 and T3) in the blood serum of A. latus fingerlings showed a clear variations upon salinity changes in the short term effect experiment as a transit status reflecting the capability of these fingerlings to adapt to wide range of salinities vary from 1.5 psu to 30 psu, and the salinity 45 psu was out of its tolerance range.

OSMOTIC PERFORMANCE AND GROWTH RATE OF STRIPED CATFISH (Pangasianodon hypohthalmus) AT DIFFERENT SALINITY

The aim of this study was to analyze the effects of different salinities on osmotic performance rate, growth performance, and oxygen consumption rate Pangasianodon hypophthalmus. The method used is an experimental method by applying a completely randomized design (CRD) with four treatments, salinity 0 ppt, salinity 5 ppt, salinity 7 ppt, and salinity 9 ppt. The fish specimen used is 8 cm in length, weighing 4 g, were raised in a 54 L tank containing 40 L of water at a density of 1 fish 2 L-1 and kept for 45 days. Feed with commercial pellet 3 times a day in at satiation. The treatment with 5 ppt salinity showed the best effects, yielding an osmotic performance rate of 21,66 mOsm/I H2O, absolute weight growth of 9,63 g, the absolute length of 3.54 cm, the specific growth rate of 2,99 %, the oxygen consumption rate of 0,410 mgO2/g body weight/hour and survival rate 100 %. The water quality is at a level suitable for the growth of P. hypophthalmus. It was concluded that 5 ppt salinity can minimize the value of the osmotic performance rate, increase growth rates, minimize the level of oxygen consumption and increase

Response to salinity of the submerged aquatic vegetation species \(\textit{Najas indica}\) (Willd.) Cham.

Najas indica (Willd.) Cham is known as a freshwater species of submerged aquatic vegetation. However, this species is widely distributed in both freshwater and brackish environments. This study examined the survival, growth rate and morphological performance of N. indica collected from the Cau Hai lagoon (Thua Thien Hue) against different salinity treatments in a mesocosm experiment to determine the optimal salinity for the species. The results showed significant effects of different salinities on survival rates, growth, biomass, and the morphological characteristics of N. indica. The species could survive and continue growing at 0–15 ppt but died completely at 20 ppt and 25 ppt after the first week of the 8-week experiment. Leaf length tended to be shorter in higher salinity. Shoot length, the number of internodes and branches per shoot, biomass reached the highest values at 5 ppt and 10 ppt. These suggested that the optimal salinity of the N. indica was at a range of 5–10 ppt. Study results were informative to explain the distribution change of the freshwater originated hydrophyte N. indica in lagoon environments in Vietnam.

Acclimation response and ability of growth and photosynthesis of terrestrial cyanobacterium Cylindrospermum sp. strain FS 64 under combined environmental factors

This investigation tested the hypothesis that the native cyanobacteria can acclimatize and grow under the combination of environmental factors and/or how does their process change with the age of culture? Here, we tried to combine multiple factors to simulated what happens in natural ecosystems. We analyzed the physiological response of terrestrial cyanobacterium, Cylindrospermum sp. FS 64 under combination effect of different salinity (17, 80, and 160 mM) and alkaline pHs (9 and 11) at extremely limited carbon dioxide concentration (no aeration) up to 96 h. Our evidence showed that growth, biomass, photosystem II, and phycobilisome activity significantly increased under 80 mM salinity and pH 11. In addition, this combined condition led to a significant increase in maximum light-saturated photosynthesis activity and photosynthetic efficiency. While phycobilisomes and photosystem activity decreased by increasing salinity (160 mM) which caused decreased growth rates after 96 h. The single-cell study (CLMS microscopy) which illustrated the physiological state of the individual and active-cell confirmed the efficiency and effectiveness of both photosystems and phycobilisome under the combined effect of 80 mM salinity and pH 11.

Effects of saline water mulched drip irrigation on cotton yield and soil quality in the North China Plain

The shortage of freshwater resources is a considerable challenge for agricultural production in the North China Plain (NCP). Safe and efficient use of saline water resources is thus urgently required. To reveal the effects of different salinities of irrigation water on the yield and soil quality of mulched drip-irrigated cotton, a field experiment was conducted from 2017 to 2019. Five salinity levels of irrigation water were included: 1.3 (T1, control), 5.4 (T2), 8.8 (T3), 12.4 (T4) and 15.9 (T5) dS·m−1. The results showed that the harvesting density and seed cotton yield increased first and then decreased with increasing salinity of irrigation water. Saline water irrigation with salinity ≤ 8.8 dS·m−1 did not lead to salt accumulation in the main root zone (0–60 cm) with each passing year but a decrease of salt in 2018. In the third year of saline water irrigation, with the increase in irrigation water salinity, the electrical conductivity of the saturated soil extract (ECe), soil sodium adsorption ratio (SAR), pH and bulk density (BD) in the plow layer gradually increased. However, the soil saturated hydraulic conductivity (Ks), water stable macroaggregate (> 0.25 mm) content, catalase (CAT) and urease (URE) activity decreased with increasing salinity. Moreover, the soil organic carbon (SOC) content and alkaline phosphatase (ALP) activity increased first and then decreased. Irrigation water salinity ≤ 5.4 dS·m−1 had no significant effect on most physicochemical properties, such as pH, SOC content, BD, Ks, water stable aggregate content and activities of CAT, URE and ALP. Compared with the T1 treatment, the soil quality index (SQI) of T2, T3, T4 and T5 treatments decreased by 1.2%, 10.5%, 16.5% and 23.7%, respectively. Considering cotton yield, soil salt accumulation and SQI, mulched drip irrigation is conducive to the sustainability of cotton with saline water levels below 5.4 dS·m−1.

Interactive effect of salinity and Ca to Mg ratio of irrigation water on pistachio growth parameters and its ionic composition in a calcareous soil

ABSTRACT This study investigated the effect of different salinity (EC≈6 and 9 dS/m) and Ca/Mg ratios (≈0.95,0.50, and 0.25) in irrigation water on the chemical composition of soil solution and growth of pistachio (Pistacia vera L.). The physiological, biochemical, and yield-related responses of pistachio seedlings were measured within ≈30 weeks in a greenhouse pot experiment. The EC of the soil solutions rapidly approached the one in the irrigation waters while the Ca/Mg ratios slowly altered, as such the final ratios were ≈50-100% larger than the one in the irrigation waters. The slower change in the Ca/Mg ratio is due to the fact that Ca concentration is dominantly controlled by the calcite solubility but the Mg concentration by the ion-exchange reaction. With increasing EC of the soil solution from 5.8–10.4 dS/m, we found 4-fold reduction in shoot dry weight and 62% increase in electrolyte leakage. In each salinity level, the highest yield and membrane stability were achieved at the Ca/Mg ratio of ≈1 in the soil solution. Overall, a Ca/Mg ratio < 1 in the irrigation water shifted the ionic composition of the soil solution, even in calcareous soil, towards a ratio < 1 and negatively affected pistachio growth.

Germination patterns along a salinity gradient of closely-related halophytes in sympatry

Sympatric closely-related species co-occur within heterogeneous environments by occupying separate ecological niches as result of adaptive differentiation. Soil salinity is one of the most relevant drivers leading plant zonation in salt marshes, where germination is a critical stage in the life cycle of many halophytes. Salinity influence on germination patterns was evaluated for six sympatric Limonium species (L. admirable, L. caesium, L. cossonianum, L. delicatulum, L. supinum and L. tobarrense), which grow under arid environmental conditions in an inland salt marsh from the southeastern Spain. Experiments were conducted to determine the effects of different salinities (0–6% NaCl) on seed germination under 12 h in light at 25 °C and for 12 h in dark at 20 °C. Best seed germination was obtained under non-saline conditions, and germination was delayed and significantly reduced by increasing the salinity levels for all the studied taxa. The germination variables related to final germination percentage, mean time to germination and recovery were directly influenced by salinity. Seeds recovered their germination capacity after transferring the seeds from saline solutions to distilled water, especially those seeds previously treated under high salinity conditions. Our results suggest that the successful establishment of Limonium communities depends on the germination strategy which implies a rapid germination velocity when the soil salinity decreases. Two different germination syndromes based on germination percentage and germination recovery have been found. Hence, these germination strategies would favour the adaptation of different Limonium species under favorable conditions, shaping the plant asssembly within the saline habitat.

Effect of different salinity on the growth performance and proximate composition of isolated indigenous microalgae species

The suitable culture condition for specific microalgae species is vitally important for their optimal growth and biochemical production. Therefore, this study emphasized on the isolation and screening of indigenous microalgae species with high growth performance from Setiu wetlands, Terengganu, Malaysia. Successfully isolated microalgae were identified based on morphological and molecular approaches using 18S rDNA technique. Microalgae were screened to identify their species with high growth performance based on optical density and Nile red fluorescence dye. Further, the effect of different salinity towards the growth performance of isolated microalgae and proximate composition including protein, lipid, and carbohydrate were identified. Out of nine microalgae strain, three species of indigenous microalgae were successfully isolated and identified known as Chlorella vulgaris, Tetraselmis chuii, and Isochrysis galbana during 16 days of culture period. The highest optical density was found in C. vulgaris, T. chuii, and I. galbana with 1.228 ± 0.039 a.u, 0.758 ± 0.024 a.u and 0.853 ± 0.048 a.u, respectively. Chlorella vulgaris, T. chuii, and I. galbana were also showed the highest specific growth rate with 0.548 μmax/day, 0.686 μmax/day and 0.478 μmax/day, respectively. Using Nile red fluorescent dye screening, C. vulgaris, T. chuii and I. galbana also showed the highest fluorescence intensity of lipid, carotenoid and chlorophyll a content. Based on these criteria, C. vulgaris, T. chuii and I. galbana were selected for further determination on the effect of salinity towards the growth and proximate composition of the selected microalgae. The optimum salinity level of culture medium for T. chuii was 40 ppt with the highest cell density (6.215 × 106 cells/mL; Day 6), protein content (40.47 ± 0.51% of dry weight) and carbohydrate content (42.57 ± 0.83% of dry weight). For I. galbana, 24 ppt was found to be the best culture medium in term of the highest cell density (20.58 × 106 cells/mL; Day 7), and carbohydrate content (29.28 ± 0.47% of dry weight), while lipid content was highest at 40 ppt (15.68 ± 0.58% of dry weight). For C. vulgaris, 10 ppt was the best culture medium in term of the highest cell density (31.17 × 106 cells/mL) and lipid content (13.12 ± 1.12% of dry weight), while carbohydrate and protein content were highest at 0 ppt with 44.53 ± 0.56% and 40.16 ± 2.22% of dry weight, respectively. Overall, the variation of salinity had affected the growth and biochemical compositions of C. vulgaris, T. chuii and I. galbana. Therefore, this study is important for the cultivation of C. vulgaris, T. chuii and I. galbana of different specific target by manipulating the salinity variation of culture medium that can be used as a feed in aquaculture industry.

Mechanism of pore relative humidity on salt swelling characteristics in sulfate saline soil

Crystallization of sodium sulfate into mirabilite in sulfate saline soil harms the soil potential and intensifies the reparative expenses for subgrade. However, the effects of pore relative humidity (PRH) on the salt swelling behavior have not been thoroughly explored. The multiple-humidity cycles experiments, in this paper, were performed to investigate salt swelling behavior in sulfate saline soil. The effects of different salinity, temperatures, and PRH values on salt swelling displacement (SSD) and salt swelling rate (SSR) of sulfate saline soil were analyzed. The X-ray Diffraction (XRD) technique was employed to investigate the mineral composition of post-experiment soil samples. All test results show that the SSD and SSR of soil samples increase with the increase of PRH and salinity and decreases as the increasing temperature. The enhancement of salt swelling in the presence of PRH was 80-90-80%. Besides, XRD results denote that the existence of mirabilite in the test soil samples verified for the salt swelling to be closely related to PRH in terms of microstructure. All the results further improve the mechanism of salt swelling in sulfate saline soil in the presence of PRH, which is of great significance to analysis and remediation of salt swelling behavior.

Effects of different salinity on the transcriptome and antibiotic resistance of two Vibrio parahaemolyticus strains isolated from Penaeus vannamei cultured in seawater and freshwater ponds.

The transcriptome and antibiotic resistance of Vibrio parahaemolyticus isolated from Penaeus vannamei cultured in seawater (strain HN1)and freshwater (strain SH1) ponds were studied at different salinity (2‰ and 20‰). At different salinity, 623 differentially expressed genes (DEGs) significantly upregulated and 1,559 DEGs significantly downregulated in SH1. In HN1, 466 DEGs significantly upregulated and 1,930 DEGs significantly downregulated, indicating high salinity can lead to the downregulation of most genes. In KEGG analysis, the expression of DEGs annotated to starch and sucrose metabolism pathway was higher at 2‰ salinity than at 20‰ salinity in HN1 and SH1, implying salinity affected bacterial growth mainly through this pathway. In the enrichment analysis of upregulated DEGs, two pathways (Valine, leucine, and isoleucine degradation, and Butanoate metabolism) were significantly enriched at different salinity. Antibiotic-susceptibility test discovered that SH1 isolated from P. vannamei cultured in freshwater was resistant to multiple drugs, including kanamycin, gentamicin, medemycin, and azithromycin, at a salinity of 2‰, whereas at 20‰ salinity, SH1 was not resistant to the drugs. The HN1 strain isolated from P. vannamei cultured in mariculture was resistant to polymyxin B and clindamycin at 20‰ salinity. Whereas, HN1 was intermediately susceptible to these two antibiotics at 2‰ salinity. These results indicate that the drug resistance of bacteria was affected by salinity. Furthermore, beta-lactam resistance was significantly enriched in SH1 at different salinity, and the inhibition zone of penicillin G was consistent with the results of a beta-lactam resistance pathway.