Effects of NaCl and CaCl2 Salinization on Morpho-Anatomical and Physiological Traits of Potted Callistemon citrinus Plants

The aim of this work was to assess the possible coordination mechanisms between leaf functional anatomical traits and physiological acclimation of potted Callistemon citrinus plants when subjected to two saline iso-osmotic solutions using NaCl or CaCl2. Digital image analysis was applied to quantify anatomical parameters with a specific focus on the occurrence of signs of structural damage as well as on alterations, such as the occurrence of shrunk tissues and accumulation of phenolic compounds. Morpho-anatomical analyses were accompanied by measurements of leaf gas exchange and chlorophyll fluorescence emission. Results showed that C. citrinus plants, when irrigated with the CaCl2 solution, induced a leaf morpho-anatomical structure which did not allow the maintenance of high photosynthetic performance under such conditions, compared to both controls and plants treated with the iso-osmotic solution of NaCl. Data collected seem to suggest a close relationship between anatomical traits and eco-physiological strategies in maintaining the photosynthetic efficiency under saline stress conditions and highlight the fundamental role of leaf anatomy in imposing the limits of plant physiology.

Production of Omega-3 Oil by Aurantiochytrium mangrovei Using Spent Osmotic Solution from Candied Fruit Industry as Sole Organic Carbon Source

Osmotic dehydration is an important phase in the production of dried products, including most fruits and vegetables, in the food industry. The drying process for candied fruit produces a liquid waste called “spent osmotic solution”, which is characterized by a high content of organic compounds, mostly dissolved sugars. The sugar content of this food by-product could be valorized through the growth of biomass with a high added value. In this study, the spent osmotic solution from the candied fruit industry was used as an organic carbon source for the growth and production of docosahexaenoic acid (DHA) in the cultivation of Aurantiochytrium mangrovei RCC893. The carbon content of the standard media was completely replaced by the sugars present in this food by-product. After that, the growth condition of this strain was optimized through response surface methodologies using a central composite design (CCD), and the optimal combination of the spent osmotic solution and nitrogen was established. Moreover, a scale-up trial was performed using the optimal conditions obtained after CCD to evaluate the scalability of the process.

Evaluation of physiochemical characteristics of fresh and osmotic dehydrated fig (Ficus carica L.)

Fig (Fiscus carica L.) fruits being the rich source of phytochemicals, particularly anti-oxidants serve as a powerhouse of nutrients and has many medicinal properties. Fig promoting healthy bowel function due to the high level of fiber. Rich in vitamins A,C,E, and minerals like calcium useful to improve the health status and to balance the pH of the body. Due to its short-lived nature, it cannot be stored for longer period (2-3 days) because higher postharvest losses. The lag in processing of fig is mainly attributed to the highly perishable nature of the fig as it posses high moisture content. The objective of the work was to improve the shelf life and reduce the perishability of fig. Two varieties, namely Local and Timla (Yercud - 1) variety were selected and osmotically dehydrated with different concentration (30, 40 and 50 °brix) of sugar solution. Timla variety contained lower percentage of seeds (21%) and fibre (2.05 g/100g), higher pulp thickness (1.0 cm), maximum colour values (L - 70.30, a - 4.65 and b - 12.37), TSS (19°brix) and vitamin C (39.0 mg/100g) than the local variety. Timla variety treated with 50° brix osmotic solution was found better nutrient retention, drying characteristics and organoleptic properties. The resultant products had improved shelf life and increased concentration of nutrients, making it suitable for processing and value addition.

Development of mass and heat transfer coupled model of hollow fiber membrane for salt recovery from brine via osmotic membrane distillation

Background In this research work, a coupled heat and mass transfer model was developed for salt recovery from concentrated brine water through an osmotic membrane distillation (OMD) process in a hollow fiber membrane contactor (HFMC).The model was built based on the resistance-in-series concept for water transport across the hydrophobic membrane. The model was adopted to incorporate the effects of polarization layers such as temperature and concentration polarization, as well as viscosity changes during concentration. Results The modeling equations were numerically simulated in MATLAB® and were successfully validated with experimental data from literature with a deviation within the range of 1–5%. The model was then applied to study the effects of key process parameters like feed concentrations, osmotic solution concentration, feed, and osmotic solution flow rates and feed temperature on the overall heat and mass transfer coefficient as well as on water transport flux to improve the process efficiency. The mass balance modeling was applied to calculate the membrane area based on the simulated mass transfer coefficient. Finally, a scale-up for the MD process for salt recovery on an industrial scale was proposed. Conclusions This study highlights the effect of key parameters for salt recovery from wastewater using the membrane distillation process. Further, the applicability of the OMD process for salt recovery on large scale was investigated. Sensitivity analysis was performed to identify the key parameters. From the results of this study, it is concluded that the OMD process can be promising in salt recovery from wastewater.

Effect of Filtrated Osmotic Solution Based on Concentrated Chokeberry Juice and Mint Extract on the Drying Kinetics, Energy Consumption and Physicochemical Properties of Dried Apples

Background: Filtration of osmotic solution affects selective penetration during osmotic dehydration (OD), and after drying is finished, this can influence the chemical composition of the material, which is also modified by OD. Methods: Osmotic dehydration was carried out in filtrated and non-filtrated concentrated chokeberry juice with the addition of mint infusion. Then, this underwent convective drying, vacuum-microwave drying and combined convective pre-drying, followed by vacuum-microwave finishing drying. Drying kinetics were presented and mathematical models were selected. The specific energy consumption for each drying method was calculated and the energy efficiency was determined. Results and Discussion: The study revealed that filtration of osmotic solution did not have significant effect on drying kinetics; however, it affected selective penetration during OD. The highest specific energy consumption was obtained for the samples treated by convective drying (CD) (around 170 kJ·g−1 fresh weight (fw)) and the lowest for the samples treated by vacuum-microwave drying (VMD) (around 30 kJ·g−1 fw), which is due to the differences in the time of drying and when these methods are applied. Conclusions: Filtration of the osmotic solution can be used to obtain the desired material after drying and the VMD method is the most appropriate considering both phenolic acid content and the energy aspect of drying.

Modelling of Thin-Layer Drying of Osmo-Pretreated Red Bell Pepper

The paper observes a thin-layer drying behaviour of red bell pepper. The red bell pepper (192 samples) was pretreated in osmotic solution of salt of concentrations 5–20% (w/w) at osmotic solution temperatures (30–60 °C) and osmotic process durations (30–120 min) and dried at 60 °C in a locally fabricated convective dryer after preformation of osmotic dehydration pretreatment process. Experimental moisture content values obtained from the drying process were converted to moisture ratios. Seven existing thin-layer drying model equations were used for model equation fitting. The predicted and experimental (observed) moisture ratios were analysed statistically. The statistical indices and rules used to judge and select the model equation that would best describe the process were the highest values of coefficient of determination (R 2); the lowest values of chi-square (χ2), root mean square error (RMSE), and sum of squares error (SSE). Results showed that the two-term exponential model equation best described the drying behaviour of osmo-pretreated red bell pepper. The ranges of statistical indices of selected two-term exponential model equation are: R 2 (0.9389–0.9751), χ2 (0.0642–0.1503), RMSE (0.2032–0.1668), and SSE (0.6424–1.5027).

The Application of Bicarbonate Recovers the Chemical-Physical Properties of Airway Surface Liquid in Cystic Fibrosis Epithelia Models

Cystic fibrosis (CF) is a genetic disease associated with the defective function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein that causes obstructive disease and chronic bacterial infections in airway epithelia. Deletion of phenylalanine at position 508, p.F508del, the most frequent mutation among CF patients, causes a folding and traffic defect, resulting in a dramatic reduction in the CFTR expression. To investigate whether the direct application of bicarbonate could modify the properties of the airway surface liquid (ASL), we measured the micro-viscosity, fluid transport and pH of human bronchial epithelial cells monolayers. We have demonstrated that the treatment of a CF-epithelia with an iso-osmotic solution containing bicarbonate is capable of reducing both, the ASL viscosity and the apical fluid re-absorption. We suggest the possibility of design a supportive treatment based on topical application of bicarbonate, or any other alkaline buffer.

In Vitro Screening of Cucmis Melo L. Against Drought Mediated By PEG and Sorbitol

Water deficit in first growth stages of melon (Cucumis melo L.) in formation of first true leaves after germination can be a factor limiting production. The first step for resolve the problem is genotypes evaluation and identification of drought tolerant melons. An effective method to achieve the goal is use of osmotic solution in tissue culture. Responses of Iranian melon landraces to drought was evaluated using sorbitol at 0.1, 0.2 and 0.4 M or polyethyleneglycol (PEG 6000) at 0.009, 0.012 and 0.015 M concentrations, and MS medium without treatment as the control. Coleoptile length, fresh and dry weight of shoots and roots, photosynthetic pigments, protein, proline, malondialdehyde (MDA) and antioxidant enzymes superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase were measured. The PEG or sorbitol decreased coleoptile length, fresh weight and photosynthetic pigments, and led to enhancement of proline and MDA. Contents of protein and antioxidant enzymes was completely dependent on genotype and type and concentration of osmotic material. The in vitro culture for screening and identification of tolerant and sensitive drought genotypes could be rapid, useful and effective, with sorbitol mimicing drought better than PEG. After in vitro evaluation, the genotype responses to induced water deficit need to be confirmed under field conditions.

Stomatal morphology and physiology explain varied sensitivity to abscisic acid across vascular plant lineages

Abscisic acid (ABA) can induce rapid stomatal closure in seed plants, but the action of this hormone on the stomata of fern and lycophyte species remains equivocal. Here, ABA-induced stomatal closure, signaling components, guard cell K+ and Ca2+ fluxes, vacuolar and actin cytoskeleton dynamics, and the permeability coefficient of guard cell protoplasts (Pf) were analyzed in species spanning the diversity of vascular land plants including 11 seed plants, 6 ferns, and 1 lycophyte. We found that all 11 seed plants exhibited ABA-induced stomatal closure, but the fern and lycophyte species did not. ABA-induced hydrogen peroxide elevation was observed in all species, but the signaling pathway downstream of nitric oxide production, including ion channel activation, was only observed in seed plants. In the angiosperm faba bean (Vicia faba), ABA application caused large vacuolar compartments to disaggregate, actin filaments to disintegrate into short fragments and Pf to increase. None of these changes was observed in the guard cells of the fern Matteuccia struthiopteris and lycophyte Selaginella moellendorffii treated with ABA, but a hypertonic osmotic solution did induce stomatal closure in fern and the lycophyte. Our results suggest that there is a major difference in the regulation of stomata between the fern and lycophyte plants and the seed plants. Importantly, these findings have uncovered the physiological and biophysical mechanisms that may have been responsible for the evolution of a stomatal response to ABA in the earliest seed plants.

Drought tolerance selection of GT1 rubber seedlings with the addition of polyethylene glycol (PEG) 6000

Pasaribu SA, Basyuni M, Purba E, Hasanah Y. 2021. Drought tolerance selection of GT1 rubber seedlings with the addition of polyethylene glycol (PEG) 6000. Biodiversitas 22: 394-400. Tolerance of the rootstock of rubber to drought stress is not optimal. The root system can therefore be used as an indicator of drought tolerance to inhibit the growth of the plant. A good root system of rubber rootstocks is thought to help the plants acquire greater resistance to drought stress. Polyethylene glycol 6000 osmotic solution controls the water potential in the growing medium. This study aimed to analyze the effect of PEG 6000 osmotic solution (0%; 7.5%; and 15% concentration) on rubber seedlings leading to the development of morphological characters and sensitivity index. GT1 (Gondang Tapen 1) rubber seeds to be used as planting material were collected from the seed source garden of PT Socfin Indonesia. The study was carried out from January to February 2019, using a non-factorial randomized block design. The morphological characters observed were tapped root length, shoot height, the increased rate of taproot length, shoot height increase rate, ratio of taproot length, and shoot height. Data were analyzed using analysis of variance, discriminant, and drought stress sensitivity index. The results showed that the addition of PEG 6000 in planting media in vitro significantly influenced the character of the rate of increase of taproot length. The sensitivity index of taproot increase rate and the ratio of taproot length and shoot height was moderate at 7.5% levely contrast, the addition of PEG 6000 in planting media in vitro did not significantly impact it. The present study suggested that the rate of increase of taproot length was a distinguishing character showing the initial tolerance level of the GT1 seedlings to drought.