Trehalose

Freeze dried surimi powder is a surimi type that has been processed through freeze drying. To utilize oversized catfish and to reduce surimi handling cost, oversized catfish has been used as raw material of surimi powder. The study aimed to determine the effect of defatting (NaHCO3 concentration and soaking duration), washingcycle,and dryoprotectant type on catfish surimi, as well as quality differences between surimi powder and wet surimi. With regard to defatting step, soaking in NaHCO3 0.75% for 10 min was found as the best treatment and resulting in a fat content of 1.52%. Moreover, one time of washing cycle was found as the most appropriate procedure to obtain a superior quality of surimi whiteness value 57.21%, water holding capacity 73.28%, salts soluble protein 7.17%, pH 6.69, and gel strength 482.3 g/cm2, folding value of 4.84, teeth cutting value of 8.26, respectively. Trehalose 6% was the most suitable dryoprotectant resulting in surimi powder with water holding capacity of 8.01 mL/g, gel strength 826.3 g/cm2, salt soluble protein 18.98%, density 4.06 mL/10 g, rehydration capacity 3.81, emulsion capacity 69.3%, emulsion stability 59.3%, foaming capacity 25.33% and foaming stability 9.40%. The microstructure profile of surimi powder added with trehalose had more compact tissues, consisted of no damage and clots, than in surimi treated with other dryoprotectants. However, surimi powder still had lower protein content than in wet surimi, and lower physical and chemical properties, particularly its teeth cutting and folding characteristics.

A number of naturally occurring small organic molecules, primarily involved in maintaining osmotic pressure in the cell, display chaperone-like activity, stabilizing the native conformation of proteins, and protecting them from various kinds of stress. Most of them are sugars, ...

El metabolismo es el conjunto de reacciones químicas que realizan las células de los seres vivos para sintetizar sustancias complejas a partir de otras más simples, o para degradar las complejas y obtener las simples (Ávalos y Pérez-Urria, 2009). El pequeño tamaño de los insectos, en comparación con otros organismos, ha resultado en una evolución distinta y por lo tanto han desarrollado un metabolismo con variaciones significativas. Sin embargo, hay rutas metabólicas que muchos grupos de seres vivos tienen en común. En este artículo se explican de manera general algunas rutas metabólicas llevadas a cabo en los insectos.

Following tuber induction, potato tubers undergo a period of dormancy during which visible bud growth is inhibited. The length of the dormancy period is under environmental, physiological and hormonal control. Sucrose availability is one prerequisite for bud break. In the absence of sucrose, no bud break occurs. Thus, sucrose is likely to serve as nutrient and signal molecule at the same time. The mode of sucrose sensing is only vaguely understood, but most likely involves trehalose-6-phosphate and SnRK1 signalling networks. This conclusion is supported by the observation that ectopically manipulation of trehalose-6-phosphate levels influences the length of the dormancy period. Once physiological competence is achieved, sprouting is controlled by the level of phytohormones. Two phytohormones, ABA and ethylene, are supposed to suppress tuber sprouting; however, the exact role of ethylene remains to be elucidated. Cytokinins and gibberellins are required for bud break and sprout growth, respectively. The fifth classical phytohormone, auxin, seems to play a role in vascular development. During the dormancy period, buds are symplastically isolated, which changes during bud break. In parallel to the establishment of symplastic connectivity, vascular tissue develops below the growing bud most likely to support the outgrowing sprout with assimilates mobilised in parenchyma cells. Sprouting leads to major quality losses of stored potato tubers. Therefore, control of tuber sprouting is a major objective in potato breeding. Although comparative transcriptome analysis revealed a large number of genes differentially expressed in growing versus dormant buds, no master-regulator of potato tuber sprouting has been identified so far.

Baker’s yeast (Saccharomyces cerevisiae) is still one of the most important fermentation product based on the volume of sales and its use for bread-making. New products with better and sophisticated properties that can grow easily on cheap substrates make the search for new and improved industrial strains a promising talk. The present study was envisaged to utilize easily available agro-industrial wastes for biomass production of the yeast isolate (FJ1) having some industrially important attributes (high trehalose content and freeze tolerance) and to compare this isolate with the commercial yeast strains. Seven commercially available Baker’s yeasts formulations procured from local market were screened for their microbiological contaminants and were compared w.r.t morphological, physiological and biochemical characteristics with a laboratory isolate (FJ1). Freeze tolerance of all these yeast isolate was studied upto 90 days, whereby, freeze tolerance of FJ1 was comparable with the commercial strain (Allinson). Allinson yeast showed maximum assimilation of maltose which is the main sugar available for fermentation in flour. Allinson and FJ1 showed significantly higher carbohydrate content (%) of 33.62 and 33.89, while for all other 6 brands it was at par. Trehalose content was highest for FJ 1 (5.0 g/100g DW) followed by Falora, Platinum and Allinson, whereas invertase activity was highest in Allinson (205 U/mg). On the basis of the above mentioned properties Allinson was selected as a reference strain and compared with FJ1 isolate for bread making. Optimum conditions for maximum biomass production of both these strains were pH - 6.0, temperature - 30°C and aeration - 120 RPM. Out of the five selected agro-industrial wastes viz. molasses (clarified), molasses (unclarified), whey, sugarcane bagasse and fruit bagasse, maximum biomass production was observed on molasses (un-clarified) as carbon source and with supplementation of corn steep liquor (CSL) as a nitrogen source. At optimized conditions, FJ1 showed biomass yield of 5.63g/L which further increases to 6.54g/L on supplementation with CSL. Therefore, CSL was found to increase the biomass yield by 16.16%. Bread prepared by using FJ1 was compared with that produced from Allinson on nine points hedonic scale for consumer acceptability and quality analysis.

Post cryopreservation viability of human embryonic kidney (HEK) cells under two-dimensional (2D) and three-dimensional (3D) culture conditions was studied using trehalose as the sole cryoprotective agent. An L(3) Taguchi design was used to optimize the cryoprotection cocktail seeding process prior to slow-freezing with the specific aim of maximizing cell viability measured 7 days post thaw, using the combinatorial cell viability and in-vitro cytotoxicity WST assay. At low (200 mM) and medium (800 mM) levels of trehalose concentration, encapsulation in alginate offered a greater protection to cryopreservation. However, at the highest trehalose concentration (1200 mM) and in the absence of the pre-incubation step, there was no statistical difference at the 95% CI (p = 0.0212) between the viability of the HEK cells under 2D and 3D culture conditions estimated to be 17.9 ± 4.6% and 14.0 ± 3.6%, respectively. A parallel comparison between cryoprotective agents conducted at the optimal le...

Trehalose, a non-permeating cryoprotective agent (CPA), has been documented as less toxic and highly efficient at cryopreserving different kinds of cells or organisms. In the present study, trehalose was evaluated for its application in cryopreservation of both Trypanosoma brucei procyclic and bloodstream form cells. The cryopreservation efficiency was determined by the motility of trypanosomes after thawing, as well as a subsequent recovery and infectivity assessment. The viability of trypanosomes from cultivation that were frozen in a serial concentrations of trehalose showed similar results to classical CPAs of glycerol and DMSO. Nevertheless, trypanosomes cryopreserved in 0.2M trehalose showed the best growth characteristic during subsequent cultivation. In addition, CPA cocktails with trehalose and permeating CPA glycerol or DMSO were developed and evaluated. Interestingly, trypanosomes in host (mouse) blood cryopreserved in 0.4M trehalose plus 5% glycerol showed higher infecti...

Background Quantitative real-time PCR (qPCR) is becoming increasingly important for DNA genotyping and gene expression analysis. For continuous monitoring of the production of PCR amplicons DNA-intercalating dyes are widely used. Recently, we have introduced a new qPCR mix which showed improved amplification of medium-size genomic DNA fragments in the presence of DNA dye SYBR green I (SGI). In this study we tested whether the new PCR mix is also suitable for other DNA dyes used for qPCR and whether it can be applied for amplification of DNA fragments which are difficult to amplify. Results We found that several DNA dyes (SGI, SYTO-9, SYTO-13, SYTO-82, EvaGreen, LCGreen or ResoLight) exhibited optimum qPCR performance in buffers of different salt composition. Fidelity assays demonstrated that the observed differences were not caused by changes in Taq DNA polymerase induced mutation frequencies in PCR mixes of different salt composition or containing different DNA dyes. In search for a PCR mix compatible with all the DNA dyes, and suitable for efficient amplification of difficult-to-amplify DNA templates, such as those in whole blood, of medium size and/or GC-rich, we found excellent performance of a PCR mix supplemented with 1 M 1,2-propanediol and 0.2 M trehalose (PT enhancer). These two additives together decreased DNA melting temperature and efficiently neutralized PCR inhibitors present in blood samples. They also made possible more efficient amplification of GC-rich templates than betaine and other previously described additives. Furthermore, amplification in the presence of PT enhancer increased the robustness and performance of routinely used qPCRs with short amplicons. Conclusions The combined data indicate that PCR mixes supplemented with PT enhancer are suitable for DNA amplification in the presence of various DNA dyes and for a variety of templates which otherwise can be amplified with difficulty.