Various Concentrations Of Sorbitol Research Articles

Improvement of Polyethylene Glycol, Sorbitol, Mannitol, and Sucrose-Induced Osmotic Stress Tolerance through Modulation of the Polyamines, Proteins, and Superoxide Dismutase Activity in Potato

The present study was planned to investigate the changes in morphological and biochemical parameters of in vitro-grown potato (cultivar Cardinal and Desiree) plants under osmotic stress conditions induced by various concentrations of sorbitol, mannitol (0, 0.025, 0.05, 0.10, or 0.15 M), sucrose (0, 2, 3, 4, 6, and 8%), and polyethylene glycol (PEG: MW-4000: 0, 5, 10, 15, and 20%). Nodal segments (ca. 1.0 cm) from healthy in vitro-grown potato plantlets were inoculated on Murashige and Skoog’s medium consisting of various levels of above mentioned drought stress-inducing agents. Data was recorded on 60th day of incubation exhibited a severe reduction in most of the growth parameters at 0.10 and 0.15 M of sorbitol and mannitol, respectively, and at 5–10% PEG. Similar results were observed when the sucrose level varied from 3% except for the number of roots and plant dry weight, which exhibited an increase in increasing the sucrose level. Data collected for total soluble protein content and activity of an antioxidant enzyme (superoxide dismutase) unveiled an overall increasing trend in osmotically stressed potato plants suggesting their major action in detoxification of active oxygen species produced under osmotic stress. Polyamines (putrescine, spermidine, and spermine) increased significantly in both the cultivars of potato by using osmotic stress-inducing agent in the present investigation indicating their positive role in stress alleviation. Overall results indicated that potato cultivar Desiree was more stress-tolerant than the cultivar Cardinal.

Bacterial Cellulose-BasedBiodegradable Plasticfrom Pineapple (Ananassativus) Skin Waste: The Effectof Sorbitol On The QualityOf The Biodegradableplastic

The aim of this research was to investigate the effect of sorbitol on the quality ofbacterial cellulose-based biodegradable plastic from pineapple skin waste. Various concentrations of sorbitol as the plasticizer were added into a fermentation medium in the synthesis of bacterial cellulose-sorbitolcomposite (BCSC). The BCSCobtainedwas purified by soaking it into a cycled water-NaOH-water. The purified BCSC wasthen compressed using a hot press with the pressure of 300 psi to obtain BCS plastic. The BCS plasticwas characterized in the aspect of physical properties (water content,the degree of swelling), mechanical properties (tensile strength,elongation, elasticity), molecular structure (functional groups, thedegree of crystallinity), and biodegradability. The results showed that the percentage ofwater content anddegree of swelling of theBCS plastic increased with the addition of sorbitol concentrations. The maximum tensile strength was obtained with the addition of 10.5% sorbitol (%v/v). The degrability of the BCS plastic was up to 59% until the 9th day. TheFTIR results showed that functional groups appeared in the BCS plastic were similar to those of the BC. The degree of crystallinity of the BCSplastic decreased with the increasing concentration of sorbitol.

Allium cepa root meristem cells under osmotic (sorbitol) and salt (NaCl) stress in vitro

AbstractThe effects of various concentrations of sorbitol (100, 200 and 360 mM) and NaCl (100, 200 and 300 mM) on root meristem cells ofin vitro-culturedAllium cepaL. were analyzed after 10 and 20 days. Both root meristem cell cross-section area and nuclear volume decreased under osmotic and salt stress. The osmotic component of applied stresses had a greater impact on cell shrinkage, while ionic stress perturbed cell functioning, resulting in cell cycle arrest and various aberrations, affecting nucleus integrity. A concentration of 300 mM of NaCl in the culture medium caused complete inhibition of mitotic activity in onion root tip cells after 20 days of exposure. Analysis of the action of iso-osmotic concentrations of NaCl (200 mM) and sorbitol (360 mM) showed stronger mitodepressive effects of salt stress in comparison to osmotic stress.

1 H NMR investigation on the role of sorbitol for the survival of Lactobacillus paracasei ssp. paracasei in vacuum‐dried preparations

The aim of this work was to study the effect of sorbitol as protective agent on the survival of the probiotic strain Lactobacillus paracasei ssp. paracasei (F19) after vacuum drying. The survival was studied after different drying times and for various concentrations of sorbitol by plate count method. Furthermore, time domain 1H NMR studies on dehydrated suspensions of Lact. paracasei ssp. paracasei were performed to study the proton mobility in the dried samples. From the obtained signal, T2 relaxation times of single components and fractions with different proton mobility were determined. It was found out that the survival is increased by the presence of a minimum amount of sorbitol that is dependent on drying time. Furthermore, it is shown that the protective effect can only be observed below a critical water content of c. 20%. Nuclear magnetic resonance (NMR) results indicate a transition of sorbitol from liquid to solid like behaviour during drying. The onset of the transition coincides with the critical water content found for a protective effect. The data suggest that sorbitol protons are incorporated into the dried cells of Lact. paracasei ssp. paracasei (F19) below the critical water content and therefore leading to an enhanced survival. The results help to better understand the underlying mechanism of protection of Lact. paracasei ssp. paracasei using sorbitol and to establish vacuum drying as potential alternative drying technique to standard freeze drying.

Preferential Phosphorylation of Focal Adhesion Kinase Tyrosine 861 Is Critical for Mediating an Anti-apoptotic Response to Hyperosmotic Stress

The results presented here demonstrate that focal adhesion kinase (FAK) Tyr-861 is the predominant tyrosine phosphorylation site stimulated by hyperosmotic stress in a variety of cell types, including epithelial cell lines (ileum-derived IEC-18, colon-derived Caco2, and stomach-derived NCI-N87), FAK null fibroblasts re-expressing FAK, and Src family kinase triple null fibroblasts (SYF cells) in which c-Src has been restored (YF cells). We show that hyperosmotic stress-stimulated FAK phosphorylation in epithelial cells is inhibited by Src family kinase inhibitors PP2 and SU6656 and that it does not occur in SYF cells. Unexpectedly, hyperosmotic stress-induced phosphorylation of FAK at Tyr-397, Tyr-576, and most dramatically at Tyr-861 was completely insensitive to the F-actin-disrupting agents, latrunculin A and cytochalasin D. Finally, we show that in FAK null cells exposed to hyperosmotic stress or growth factor withdrawal, re-expression of wild type FAK restored cell survival, whereas re-expression of FAK mutated from tyrosine to phenylalanine at position 861 (FAKY861F) did not. Our results indicate that FAK Tyr-861 phosphorylation is required for mammalian cell survival of hyperosmotic stress. Furthermore, the results suggest that FAK is an upstream regulator (rather than downstream effector) of F-actin reorganization in response to hyperosmotic stress. We propose that FAK/c-Src bipartite enzyme is a sensor of cytoplasmic shrinkage, and that the phosphorylation on FAK Tyr-861 by Src and subsequent reorganization of F-actin can initiate an anti-apoptotic signaling pathway that protects cells from hyperosmotic stress.

凍結乾燥によるコイ筋原繊維タンパク質の変性に対するソルビトールの防止効果

To study the preventive effect of sorbitol against denaturation of myofibrillar protein by freeze-drying, carp myofibrils suspension was mixed with various concentrations of sorbitol in a medium containing 0.16M KCl and 40mM Tris-buffer (pH 7.5), and the changes in Ca-ATPase activity were measured as a function of freeze-drying time. The results obtained were as follows: (1) The activity of Ca-ATPase decreased rapidly in the initial 2h freeze-drying and remained at a definite value during the subsequent freeze-drying period. Thus the first rate constant (kD) for inactivation of Ca-ATPase in the early period was estimated. (2) As the log-arithmic value of kD was inversely proportional to the concentration (a) of sorbitol, the protec-tive effect (E) of sorbitol against the denaturation of myofibrillar protein caused by freeze-drying in the presence of a 1 M sorbitol was estimated in the following equation: E=Δlog kD/a(M-1). (3) As there was a proportional relation between the logarithmic value of remaining Ca-ATPase activity after 2h freeze-drying and concentration (a) of sorbitol, another index (R) for evaluation of the preventive effect of sorbitol against the freeze-drying denaturation of myofibrillar protein was devised as R=Δlog A/a(M-1), where A is the relative value of myofidril-lar Ca-ATPase activity after freeze-drying.

高濃度の中性塩によって起こるコイ・ミオシンＢの解離とソルビトールの抑制効果

Carp myosin B(2-3mg/ml) was treated at 10°C with 2.OM NaCl or KCl in the presence of various concentrations of sorbitol. During the treatment of myosin B, changes in ATP sensitivity, the amount of denatured actin, and thermal inactivation mode of Ca-ATPase were investigated with a lapse of time. The ATP sensitivity irreversibly decreased and denatured actin increased with the duration of salt treatment. Thermal inactivation mode of Ca-ATPase changed from a single first order step to a biphasic first order process by the salt treatment. The changes induced by NaCl were relatively larger than those by KCl, and sorbitol reduced these changes. After the treatment with 2.0M NaCl for 3h, dissociation of myosin from myosin B was recognized by ultracentrifugal sedimentation analysis and gel filtration profile on Sepharose-CL-4B followed by SDS-polyacrylamide gel electrophoretic analysis, and such salt-induced production of myosin monomer was also reduced by the treatment in the presence of sorbitol. These results showed that sorbitol suppressed the dissociation of myosin B into actin and myosin induced by high concentration of salt.

南極産オキアミの肝すい臓たんぱく質分解酵素によるアクトミオシンの消化性

A change in the muscular protein of Antarctic krill with its digestive protease of hepatopancreas has been studied by measuring the viscosity of actomyosin. Taking account of the instability of actomyosin, the decrease in viscosity was assayed in the presence and absence of sorbitol. The decrease in viscosity was thus found to proceed in two distinct stages: a fast first-order decrease in an early stage, followed by a relatively slow first-order decrease. The first-order rate constant (K') at the early stage was then used as a measure of digestibility of actomyosin. In the presence of 1.5 M sorbitol, actomyosin was digested with various concentrations of crude protease and at various temperatures. It was thus found that actomyosin of krill was several times more rapidly digestible than that of carp was. When the digestion was performed in the presence of various concentrations of sorbitol (0-2.5 M), the rate constant (K') was found to decrease with increasing molarity of sorbitol. From the linear relation between log K' and sorbitol (M), the K' value for actomyosin of krill without sorbitol was theoretically obtained. SDS-gel electrohporetic patterns of these digests showed that myosin heavy chain of krill was rapidly decomposed by its digestive protease, but this decomposition was effectively prevented by sorbitol.

A Bacteriological Evaluation of Boric Acid-Water-Sorbitol Solutions

A study of the effect of various concentrations of sorbitol on the antibacterial activity of boric acid in aqueous solution was made. Saturated solutions of boric acid in various concentrations of sorbitol were prepared at 25°. Zones of inhibition were determined using the agar plate method and Micrococcus pyogenes var. aureus as the test organism. Bacteriostatic or bactericidal activity was also determined. The pH of all solutions was measured in order to correlate antibacterial activity with pH.

A Solubility Study of the Boric Acid-Water-Sorbitol System at Various Temperatures

A study of the effect of various concentrations of sorbitol and temperature on the solubility and heat of solution of boric acid in water has been made. This system was studied at temperatures of 21°, 25°, 30°, 40°, 50°, and 60°. Concentrations of sorbitol ranging from 0 to 70 per cent by weight sorbitollin increments of 5 per cent were utilized in this study. The results of these experiments showed the relationship between (1) solubility of boric acid and (2) temperature and concentration of sorbitol. A phase diagram of the boric acid-water-sorbitol system is given. The heat of solution for the various systems was calculated. The specific gravity of all solutions was determined by the pycnometric method.