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Trehalose Concentration (trehalose + concentration)
Selected AbstractsEffect of trehalose on survival of Bradyrhizobium japonicum during desiccationJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2003J.G. Streeter Abstract Aims: A major reason for the ineffectiveness of legume inoculants in the field is the rapid death of rhizobia because of desiccation. The major purpose of this study was to identify conditions under which ,,, -trehalose would improve survival of Bradyrhizobium japonicum during desiccation. Methods and Results: Trehalose was added to cultures just prior to desiccation or was supplied to bacteria during the 6-day growth period. A wide variety of trehalose concentrations was tested. Trehalose added to cultures at the time of desiccation improved survival slightly, but trehalose loading during growth was much more effective in protection against desiccation. Growth of bacteria with 3 mmol l,1 trehalose increased trehalose concentration in cells by about threefold and increased survival of cells placed on soya bean [Glycine max (L.) Merr.] seeds by two- to four-fold after 2 or 24 h. Average of overall results indicate that growth of bacteria with trehalose in the medium resulted in a 294% increase in survival after 24 h of desiccation. The concentration of trehalose in cells was very highly correlated with survival of bacteria. When trehalose-loaded cells were suspended in buffer or water, 60,85% of cellular trehalose was lost in about 1 h and, in spite of these losses, survival during desiccation was not reduced. Conclusions: Accumulation of trehalose in the cytoplasm is critical to the survival of B. japonicum during desiccation. Increasing the periplasmic concentration of trehalose is also beneficial but is not so critical as the concentration of trehalose in the cytoplasm. Because B. japonicum cannot utilize trehalose as a carbon source, cells can be loaded with trehalose by providing the disaccharide during the growth period. Significance and Impact of the Study: Although it may not be practical to use trehalose as a carbon source in inoculant production, it may be possible to engineer greater trehalose accumulation in rhizobia. Trehalose concentration in cells should be a useful predictor of survival during desiccation. [source] Freeze tolerance of the yeast Torulaspora delbrueckii: cellular and biochemical basisFEMS MICROBIOLOGY LETTERS, Issue 1 2004Cecília Alves-Araújo Abstract The freeze stress responses to prolonged storage at ,20 °C in Torulaspora delbrueckii PYCC5323 were investigated. In this yeast, no loss of cell viability was observed for at least 120 days during freezing at ,20 °C, whereas a loss of 80% was observed in a commercial baker's yeast after 15 days. In the former strain, freeze resistance was dependent on an adaptation process. The primary cell target of freeze stress was the plasma membrane, preservation of its integrity being related with a lower increase of lipid peroxidation and with a higher resistance to H2O2, but not with the intracellular trehalose concentration. [source] Trehalose and trehalose-hydrolyzing enzyme in the haemolymph of Locusta migratoria infected with Metarhizium anisopliae strain CQMa102INSECT SCIENCE, Issue 4 2007HUA ZHAO Abstract Topical application of the Metarhizium anisopliae var. acridum specialist strain CQMa102 to the locust Locusta migratoria manilensis results in changes of the concentrations of trehalose and glucose in the haemolymph. Micrographs of the locust haemolymph shows Metarhizium anisopliae can effectivly penetrate the external skeleton of locust and after 2 days infection, the hyphae body will appear in the haemolymph of infected insects. The time in decrease of trehalose concentration coincided with that in increase of trehalose-hydrolysing enzyme activity in the haemolymph of the fungus-infected insects. Overlay gel analysis indicated there was considerably more trehalose-hydrolysing activity in the haemolymph of locusts infected by fungus than in controls. A comparable isoform was identified in in vitro culture of the fungus, suggesting a fungal origin for the in vivo enzyme. Haemolymph trehalose decreased significantly during mycosis of locusts by M. anisopliae. All these results suggested that this fungus may take advantage of competing nutrient utilization against the insect by its trehalose-hydrolyzing enzyme secretion. It may provide fundamental knowledge for fungal pathogenesis. [source] Effect of trehalose on survival of Bradyrhizobium japonicum during desiccationJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2003J.G. Streeter Abstract Aims: A major reason for the ineffectiveness of legume inoculants in the field is the rapid death of rhizobia because of desiccation. The major purpose of this study was to identify conditions under which ,,, -trehalose would improve survival of Bradyrhizobium japonicum during desiccation. Methods and Results: Trehalose was added to cultures just prior to desiccation or was supplied to bacteria during the 6-day growth period. A wide variety of trehalose concentrations was tested. Trehalose added to cultures at the time of desiccation improved survival slightly, but trehalose loading during growth was much more effective in protection against desiccation. Growth of bacteria with 3 mmol l,1 trehalose increased trehalose concentration in cells by about threefold and increased survival of cells placed on soya bean [Glycine max (L.) Merr.] seeds by two- to four-fold after 2 or 24 h. Average of overall results indicate that growth of bacteria with trehalose in the medium resulted in a 294% increase in survival after 24 h of desiccation. The concentration of trehalose in cells was very highly correlated with survival of bacteria. When trehalose-loaded cells were suspended in buffer or water, 60,85% of cellular trehalose was lost in about 1 h and, in spite of these losses, survival during desiccation was not reduced. Conclusions: Accumulation of trehalose in the cytoplasm is critical to the survival of B. japonicum during desiccation. Increasing the periplasmic concentration of trehalose is also beneficial but is not so critical as the concentration of trehalose in the cytoplasm. Because B. japonicum cannot utilize trehalose as a carbon source, cells can be loaded with trehalose by providing the disaccharide during the growth period. Significance and Impact of the Study: Although it may not be practical to use trehalose as a carbon source in inoculant production, it may be possible to engineer greater trehalose accumulation in rhizobia. Trehalose concentration in cells should be a useful predictor of survival during desiccation. [source] Collapse temperature of solutions important for lyopreservation of living cells at ambient temperature,BIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010Geer Yang Abstract In this study, the collapse temperature was determined using the freeze-drying microscopy (FDM) method for a variety of cell culture medium-based solutions (with 0.05,0.8,M trehalose) that are important for long-term stabilization of living cells in the dry state at ambient temperature (lyopreservation) by freeze-drying. Being consistent with what has been reported in the literature, the collapse temperature of binary water-trehalose solutions was found to be similar to the glass transition temperature (T,g , ,30°C) of the maximally freeze-concentrated trehalose solution (,80,wt% trehalose) during the freezing step of freeze-drying, regardless of the initial concentration of trehalose. However, the effect of the initial trehalose concentration on the collapse temperature of the cell culture medium-based trehalose solutions was identified to be much more significant, particularly when the trehalose concentration is less than 0.2,M (the collapse temperature can be as low as ,65°C). We also determined that cell density from 1 to 10,million cells/mL and ice seeding at high subzero temperatures (,4 and ,7°C) have negligible impact on the solution collapse temperature. However, ice seeding does significantly affect the ice crystal morphology formed during the freezing step and therefore the drying rate. Finally, bulking agents (mannitol) could significantly affect the collapse temperature only when trehalose concentration is low (<0.2,M). However, improving the collapse temperature by using a high concentration of trehalose might be preferred to the addition of bulking agents in the solutions for freeze-drying of living cells. We further confirmed the applicability of the collapse temperature measured with small-scale (2,µL) samples using the FDM system to freeze-drying of large-scale (1,mL) samples using scanning electron microscopy (SEM) data. Taken together, the results reported in this study should provide useful guidance to the development of optimal freeze-drying protocols for lyopreservation of living cells at ambient temperature for easy maintenance and convenient wide distribution to end users, which is important to the eventual success of modern cell-based medicine. Biotechnol. Bioeng. 2010;106: 247,259. © 2010 Wiley Periodicals, Inc. [source] Effect of trehalose on survival of Bradyrhizobium japonicum during desiccationJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2003J.G. Streeter Abstract Aims: A major reason for the ineffectiveness of legume inoculants in the field is the rapid death of rhizobia because of desiccation. The major purpose of this study was to identify conditions under which ,,, -trehalose would improve survival of Bradyrhizobium japonicum during desiccation. Methods and Results: Trehalose was added to cultures just prior to desiccation or was supplied to bacteria during the 6-day growth period. A wide variety of trehalose concentrations was tested. Trehalose added to cultures at the time of desiccation improved survival slightly, but trehalose loading during growth was much more effective in protection against desiccation. Growth of bacteria with 3 mmol l,1 trehalose increased trehalose concentration in cells by about threefold and increased survival of cells placed on soya bean [Glycine max (L.) Merr.] seeds by two- to four-fold after 2 or 24 h. Average of overall results indicate that growth of bacteria with trehalose in the medium resulted in a 294% increase in survival after 24 h of desiccation. The concentration of trehalose in cells was very highly correlated with survival of bacteria. When trehalose-loaded cells were suspended in buffer or water, 60,85% of cellular trehalose was lost in about 1 h and, in spite of these losses, survival during desiccation was not reduced. Conclusions: Accumulation of trehalose in the cytoplasm is critical to the survival of B. japonicum during desiccation. Increasing the periplasmic concentration of trehalose is also beneficial but is not so critical as the concentration of trehalose in the cytoplasm. Because B. japonicum cannot utilize trehalose as a carbon source, cells can be loaded with trehalose by providing the disaccharide during the growth period. Significance and Impact of the Study: Although it may not be practical to use trehalose as a carbon source in inoculant production, it may be possible to engineer greater trehalose accumulation in rhizobia. Trehalose concentration in cells should be a useful predictor of survival during desiccation. [source] Synthesis and mobilization of glycogen and trehalose in adult male Rhodnius prolixusARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2009Ana C. Mariano Abstract The vector of Chagas' disease, Rhodnius prolixus, feeds exclusively on blood. The blood meals are slowly digested, and these insects wait some weeks before the next meal. During the life of an insect, energy-requiring processes such as moulting, adult gonadal and reproductive growth, vitellogenesis, muscular activity, and fasting, lead to increased metabolism. Carbohydrates are a major source of energy and their mobilization is important. We determined the amounts of glycogen, trehalose, and glucose present in the fat body and/or hemolymph of adult males of R. prolixus and recorded the processes of accumulation and mobilization of these carbohydrates. We also tested our hypothesis that these processes are under endocrine control. The amount of glycogen in the fat body progressively increased until the fourth day after feeding (from 9.3±2.2 to 77. 3±7.5,µg/fat body), then declined to values around 36.3±4.9,µg/fat body on the fifteenth day after the blood meal. Glycogen synthesis was eliminated in decapitated insects and head-transplanted insects synthesized glycogen. The amount of trehalose in the fat body increased until the sixth day after feeding (from 16. 6±1.7 to 40. 6±5.3,nmol/fat body), decreased abruptly, and stabilized between days 7 and 15 at values ranging around 15,19,nmol/fat body. Decapitated insects did not synthesize trehalose after feeding, and this effect was reversed in head-transplanted insects. The concentration of trehalose in the hemolymph increased after the blood meal until the third day (from 0.07±0.01 to 0.75±0.05,mM) and at the fourth day it decreased until the ninth day (0.21±0.01,mM), when it increased again until the fourteenth day (0.79±0.06,mM) after the blood meal, and then declined again. In decapitated insects, trehalose concentrations did not increase soon after the blood meal and at the third day it was very low, but on the fourteenth day it was close to the control values. The concentration of glucose in the hemolymph of untreated insects remained low and constant (0.18±0.01,mM) during the 15 days after feeding, but in decapitated insects it progressively increased until the fifteenth day (2.00±0.10,mM). We recorded the highest trehalase activity in midgut, which was maximal at the eighth day after feeding (2,830±320,nmol of glucose/organ/h). We infer that in Rhodnius prolixus, the metabolism of glycogen, glucose, and trehalose are controlled by factors from the brain, according to physiological demands at different days after the blood meal. © 2009 Wiley Periodicals, Inc. [source] | ||||||||||