Effect Of Sugar Concentration Research Articles

Effect of sugar concentration on ginsenoside biosynthesis in hairy root cultures of Panax quinquefolium cultivated in shake flasks and nutrient sprinkle bioreactor

The study assessed the influence of sugar concentration (10, 20, 30, 50, 70, 100, 120 g l−1) on growth and ginsenoside biosynthesis in Panax quinquefolium hairy roots cultivated in shake flasks and a nutrient sprinkle bioreactor. The highest growth rate was achieved in medium containing 3–5 % sucrose. More than 70 g l−1 or less than 20 g l−1 sugar content in the medium induces significant inhibition of root growth when cultivated in shake flasks. The saponin content was determined using HPLC. The maximum yield (above 9 mg g−1 d.w.) of the sum of six examined ginsenosides (Rb1, Rb2, Rc, Rd, Re and Rg1) in hairy roots cultivated in shake flasks was obtained with 30 g l−1 sucrose in the medium. The sucrose concentration in the medium was found to correlate with saponin content in bioreactor-cultured specimens. A higher level of protopanaxadiol derivatives was found for lower (20 and 30 g l−1) sucrose concentrations; higher sucrose concentrations (50 and 70 g l−1) in the medium stimulated a higher level of Rg group saponins.

Effects of pH and sugar concentration in Zygosaccharomyces rouxii growth and time for spoilage in concentrated grape juice at isothermal and non-isothermal conditions

The effect of pH (1.7–3.2) and sugar concentration (64–68 °Brix) on the growth of Zygosaccharomyces rouxii MC9 using response surface methodology was studied. Experiments were carried out in concentrated grape juice inoculated with Z. rouxii at isothermal conditions (23 °C) for 60 days. pH was the variable with the highest effect on growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar concentration were also significant. In a second experiment, the time for spoilage by this microorganism in concentrated grape juice was evaluated at isothermal (23 °C) and non-isothermal conditions, in an effort to reproduce standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest impact on delaying the spoilage of the product. Thereby, a pH value below 2.0 was enough to increase the shelf life of the product for more than 60 days in both isothermal and non-isothermal conditions. The information obtained in the present work could be used by producers and buyers to predict the growth and time for spoilage of Z. rouxii in concentrated grape juice.

Rearing honey bees, Apis mellifera, in vitro 1: effects of sugar concentrations on survival and development.

A new method for rearing honey bees, Apis mellifera L. (Hymenoptera: Apidae), in vitro was developed and the effects of sugar concentrations on survival and development were studied. Seven different glucose (G) and fructose (F) compositions (0%G+0%F, 3%G+3%F, 6%G+6%F, 12%G+12%F, 0%G+12%F, 12%G+0%F, and 4%G+8%F) were tested. Larvae were able to grow to the post defecation stage without addition of sugars (Diet 1), but they were not able to metamorphose and pupate. Adults were reared from diets 2–7. The average larval survival, prepupal larval weights, adult weights, and ovariole numbers were affected significantly due to the sugar compositions in the diets. High sugar concentrations (12%G+12%F) increased the number of queens and intercastes.

Effects of temperature, pH and sugar concentration on the growth parameters of Saccharomyces cerevisiae, S. kudriavzevii and their interspecific hybrid

The effects of temperature, pH and sugar concentration (50% glucose + 50% fructose) on the growth parameters of Saccharomyces cerevisiae T73, S. kudriavzevii IFO 1802 T and the hybrid strain S. cerevisiae × S. kudriavzevii W27 were studied by means of response surface methodology based in a central composite circumscribed design. Lag phase could not be properly modelled in the wine model system, where yeasts started the fermentation in few hours after inoculation. In the case of the maximum specific growth rate ( µ max), the temperature was the most important variable for three yeasts, although the effects of sugar concentration (in T73 and W27) and pH (W27 and 1802) were also significant ( p < 0.05). The only retained interaction was between the variables temperature and pH for yeast 1802. The polynomial equations built for µ max were used both to assess the behaviour of yeasts as a function of the factors and to predict their growth. In the case of temperature, the profiles obtained by the equations showed that response of the hybrid W27 was similar to T73 and different to 1802. When pH was the factor under study, the response of the hybrid W27 was closer to 1802 than yeast T73. For sugar concentration, the response of the hybrid W27 was similar to T73 but different to 1802. To the best of our knowledge, this is the first time that predictive models are used to assess and compare the response of a hybrid strain with respect to its parental species. The information obtained could also be useful to estimate the possible effect of climatic change on yeast growth.

Bioethanol production from thick juice as intermediate of sugar beet processing

The aims of this study were to investigate the bioethanol production of thick juice as intermediate from sugar beet processing in batch culture by free Saccharomyces cerevisiae cells and the effect of sugar concentration on ethanol yield and CO2 weight loss rate. Thick juice and molasses of sugar beet from a domestic sugar factory were diluted with distilled water to give a total sugar concentration of 5, 10, 15, 20 and 25% (w w−1). Initial concentration of fermentable sugars of 20% (w w−1) in culture medium can be taken as optimal, enabling maximal ethanol yield (68%) and maximal CO2 evolution rate was realized, amounting to more than 90 g L−1 h−1. The optimal concentration of fermentable sugar from thick juice for bioethanol production by free S. cerevisiae cells was 20% (w w−1) at 30 °C, pH 5 and agitation rate 200 rpm gave maximum ethanol concentration of 12% (v v−1).

The effect of sugar concentration and temperature on growth and volatile phenol production byDekkera bruxellensisin wine

The wine spoilage yeast Dekkera bruxellensis was evaluated for the production of 4-ethylphenol under low concentrations (0.02-20 g L(-1)) of glucose and fructose in synthetic media. Measurable amounts of 4-ethylphenol were produced over 0.2 g L(-1) of each sugar. The yeast growth rate and amount of biomass formed increased from 0.2 to 20 g L(-1) of glucose or fructose, being accompanied by increasing production of 4-ethylphenol. In red wines, the production of 4-ethylphenol was only observed in the presence of growing populations of indigenous or inoculated strains of D. bruxellensis. The production rate of 4-ethylphenol varied between 22 and 93 mug day(-1) either with inoculated strains or wild populations in bottled wines. The production rate of 4-ethylphenol as a function of the increase in the number of cells varied from 349 to 1882 mug L(-1) per one log CFU mL(-1). The effect of temperature on cellular viability and 4-ethylphenol production was tested in red wines with indigenous or inoculated strains of D. bruxellensis. Incubation temperatures of 15, 20 and 25 degrees C allowed cellular growth and volatile phenol production. Increasing incubation temperatures to 36 degrees C induced full viability loss of 10 strains of D. bruxellensis within <12 h.

Effects of feeding frequency and sugar concentrations on lifetime reproductive success of Meteorus pulchricornis (Hymenoptera: Braconidae)

Many species of parasitoids can increase their reproduction through feeding on supplemental sugar sources. We evaluated the longevity both with and without hosts and progeny production of a uniparental strain of Meteorus pulchricornis by varying concentration of the sugar solution and feeding frequency. A 1:1:1 sucrose–glucose–fructose-mixture was tested in a range of concentrations (0–70% (w/v)). The parasitoid lifespan did not increase with the concentration of sugar solutions, but parasitoids feeding on a 30% sugar solution attained greater longevity than parasitoids feeding on other sugar concentrations in the absence of hosts. The same effect of sugar concentration was also observed on progeny production, where when the parasitoid was fed 30% (w/v) sugar solution, its lifetime progeny production doubled in comparison to that fed water, and increased by 50% compared to those fed the other sugar solutions. In the last experiment, we studied the effect of feeding intervals on the longevity and progeny production of M. pulchricornis. Parasitoids fed with a 30% (w/v) 1:1:1 sucrose–glucose–fructose-mixture continuously lived six times longer than unfed parasitoids, three times longer than parasitoids fed only once and two times longer than parasitoids fed once every two days in the absence of hosts. Parasitoids with continuous access to the sugar solution produced considerably more progeny than those with fewer feeding frequencies. This increasing progeny production was accomplished more through an increase in daily offspring production rather than through extending reproductive lifespan.

The effect of sugar concentration and starter culture on instrumental and sensory textural properties of chorizo-Spanish dry-cured sausage

In this study, instrumental and sensory textural properties of chorizo with different levels of glucose (0.1%, 0.5% and 1.0%) and with different starter cultures ( Lactobacillus sakei K29, Pediococcus sp. P22 and Pediococcus sp. P208) were studied as well as the relationship between them. The ripening process was followed by physico-chemical and microbiological analysis. Starter culture and concentration of glucose had a highly significant effect on pH, moreover an interactive effect of both factors was found; and also of day of ripening and both starter culture and concentration of glucose. In general terms, changes of pH over time are influenced by the presence of sugar and starter culture even if all chorizos showed at first a rapid decrease, a stay or slow decrease, and a final rise. Texture profile analysis (TPA) proved that hardness and chewiness differ significantly among chorizos with or without starter cultures, except in the batch with 0.1% sugar. Furthermore, the highest values in both textural parameters were found in batches with 0.5% and 1% sugar. The texture differences between chorizos just described were also noticeable in the sensorial evaluation. Likewise, instrumental textural attributes showed significant correlations with sensorial analysis.

Capillary electrophoretic analysis of advanced glycation endproducts formed from the reaction of reducing sugars with the amino group of glucosamine

Glucosamine (GlcN) is an amino sugar sold over-the-counter and is widely used as a dietary supplement to relieve symptoms of osteoarthritis. It is not known whether it is the GlcN alone or one of its many possible nonenzymatic glycation products that is responsible for this effect. The current study demonstrates that reducing sugars form advanced glycation endproducts (AGEs) with GlcN and, as a result, decrease GlcN autocondensation by reducing the availability of the GlcN amino group. Capillary electrophoresis (CE) was used to analyze the in vitro Maillard reaction of GlcN with glyceraldehyde (GA), glucose (Glc), and fructose (Fru) as well as their inhibition of GlcN autocondensation under physiological conditions. Formation of AGEs was monitored by UV and fluorescence spectroscopy. Major components were separated by CE using a bare capillary and UV detection at 214 nm. AGE species were separated by HPLC and were complementary to the CE results. The effects of sugar concentration and incubation time on the AGE profile are also reported for each of the GlcN reducing sugar model systems. A simple and rapid CE method was developed to analyze the AGE formation in this initial report of the reaction of reducing sugars with the amino group of GlcN.

Effect of process parameters on the production and drying of Leuconostoc mesenteroides cultures.

Leuconostoc mesenteroides BLAC was grown on MRS broth or on a carrot juice medium, and the effects of sugar concentration, type of pH control, aeration and fermentor size on viable counts were examined. The effect on viability of the type of centrifuge used to concentrate the bacterial culture was also examined. When the MRS broth had the traditional 110 mM glucose, pH control did not increase the final population. However, using a zone pH control mode, increasing the glucose content of MRS both from 110 to 220 mM almost doubled the population. In MRS broth, the amount of acetic acid produced was the same for all treatments, and was proportional to the amount of citrate consumed. There was a significantly lower cell yield in the carrot juice medium when the pH was not regulated. In the carrot juice medium, pH had a more pronounced effect on the final population level than did aeration, even though the quantity of viable cells was greater when the culture was aerated. In MRS broth, glucose was completely consumed during fermentation, but this was not the case in carrot juice medium. Aeration resulted in increased acetic acid content of the fermented medium. Viable counts were not affected by scaling the volume of the fermentation from 2 to 15 l,or by the type of centrifuge used to concentrate the cells. Cells were concentrated by a factor of 10, but in both centrifuge types, viable counts showed only an eightfold average increase. However, freeze-dried powders obtained from the continuous pilot-plant-centrifuged cultures had, on the average, 33% lower populations than those obtained from the laboratory unit.

培地の糖濃度および水ポテンシャルがウンシュウミカン培養砂じょうの糖集積に及ぼす影響

ウンシュウミカン砂じょうを糖濃度および水ポテンシャルの異なるMS寒天培地に植え付け, 砂じょうの発達および糖集積に及ぼす影響を調査した.1. スクロース5%培地では砂じょうの肥大生長は促進されるものの糖の集積は緩慢であった.スクロース10%培地では砂じょうの肥大と糖集積がみられたが, その程度は樹上果実に比べるとやや劣った.また, 培養途中で糖濃度の異なる培地に継代培養を行うと, 培地の糖濃度と連動して砂じょうの糖含量は増減した.水ポテンシャルを一定として, 培地糖濃度を変化させた場合においても培地の糖濃度の上昇に伴い, 砂じょうの糖含量が増加した.2. 培地の糖濃度を一定として水ポテンシャルを変化させた場合, 水ポテンシャルが低いほど砂じょうの肥大生長は抑制される傾向を示し, 砂じょうの糖集積は促進された.しかし, 糖組成においては一定の傾向がみられなかった.また, 培養途中で異なる水ポテンシャル培地で継代培養した場合もほぼ同様な結果であった.

Enhanced production of saikosaponins by root culture of Bupleurum falcatum L. using two-step control of sugar concentration.

The effect of sugar concentration on the production of saikosaponins was investigated using a root culture of Bupleurum falcatum L. The formation of the lateral roots, which were induced in the presence of indolebutyric acid, was suppressed as the sugar concentration was increased. After the lateral root tips had emerged from the inoculated roots, however, high concentrations of sugar showed no inhibitory effect on the development of the lateral roots. A two-step culture, with 1% sucrose at the beginning of the culture and addition of 6% sucrose at 14 days, when lateral roots have emerged, greatly improved the productivity, affording 0.8 g/l of saikosaponin-a and -d.

Effects of sugar concentration on recombinant human α 1-antitrypsin production by genetically engineered rice cell

Productivity of recombinant human α 1-antitrypsin (rAAT) with a genetically engineered rice cell using an inducible promoter has been studied by batch-wise and continuous production. A simple model explained the effect of proteases released from the disrupted cells on the rAAT degradation. Glucose concentration in the medium significantly affected the rAAT productivity in the continuous production, because the rAAT was induced by sugar depletion. When the fresh medium containing 5 mM glucose was supplied to the continuous bioreactor, induction time was long and the productivity was low, indicating that the glucose concentration in the cells was high enough as to repress the promoter. When the glucose concentration in the fresh medium was reduced to 0.5 mM, total amount of rAAT produced in 70 h cultivation reached 6.7–7.6 mg/g-dry cell, which was two times larger than the control medium without glucose.

Effects of sugar concentration and strength of basal medium on conversion of somatic embryos in Asparagus officinalis L.

The effects of sugar concentration and strength of basal medium were studied to produce plants from somatic embryos in Asparagus officinalis L. There was a significant difference among concentrations of sugar but not among kinds of sugar tested in the present experiment in growth of shoots and roots. When the sucrose concentrations were 10, 30, or 50 g l −1, the fresh weight of shoots were 31.5, 14.9, or 8.6 mg per plant and the fresh weight of roots were 14.5, 33.7, or 46.3 mg per plant, respectively. There was a significant difference among strength of basal medium in shoot growth but not in root growth. When somatic embryos were cultured in a half, full, or twice the strength of basal medium, the fresh weight of shoots were 8.9, 31.0, or 60.0 mg per plant, respectively. The effects of sugar concentration and strength of basal medium were also studied in the post-culture process of somatic embryos to produce encapsulatable units, and in the conversion process of them. Not only the sugar concentration in the conversion medium but also the concentration in the post-culture medium had significant effects on growth of shoots and roots. No significant difference was observed among strength of basal medium in the post-culture process.

Effects of sugar concentration on hummingbird feeding and energy use

We investigated the effect of sucrose concentration on the patterns of feeding, gut function, and energy management in the nectar-eating Chilean hummingbird Sephanoides sephanoides. We interpreted these results using a simple model of digestive function. The predictions of this model are: (a) Hummingbirds should exhibit 100% assimilation efficiency of sugars at all sugar concentrations; (b) Daily rates of energy intake should be positively correlated with sugar concentration; and (c) Increased sugar concentration should lead to linearly increasing meal retention times, and, therefore, to linearly increasing time intervals between meals. In agreement with the model, hummingbirds exhibited almost complete assimilation of sugars and increased meal retention times and intermeal intervals with increased sugar concentration. Hummingbirds did not, however, show any significant differences in daily energy intake when fed different sugar concentrations. Birds differed in their temporal pattern of feeding when fed solutions with sucrose solutions of contrasting concentrations. At low food sucrose concentrations (0.25 M), birds showed a burst of feeding before dark. In contrast, birds feeding on higher sucrose concentrations (0.5 M and 0.75 M) showed steadily declining feeding activity throughout the day. In addition to measuring the behavior and gut function of hummingbirds, we also measured their daily patterns of energy use using respirometry. Hummingbirds showed considerable flexibility in their patterns of energy use. The amount of energy used at night was positively correlated with the surplus of energy (intake minus diurnal expenditures) at dusk. Although birds exhibited only small variation in total daily energy budgets as a function of sugar concentration, birds feeding at the lowest sucrose concentration (0.25 M) seemed to rely on nocturnal torpor with more frequency than those fed on higher concentrations. We conclude that energy maximization is probably an inappropriate assumption for birds that are not growing, storing fat, or reproducing. We present a modification of the original model that allows assuming that birds do not maximize energy intake, but rather maintain constant rates of energy intake. We describe experiments and criteria that allow discriminating among the two models.

Trophallaxis inApis mellifera: effects of sugar concentration and crop load on food distribution

SUMMARYTrophallaxis in groups of 7 honey bee foragers (Apis mellifera) was studied in the laboratory in an experimental arena. In each group, a donor bee was fed with sucrose solution while the 6 recipient bees remained unfed. In one experiment, donor bees were fed to satiation with either 10, 20, 30, 40 or 50% (wt/wt) sucrose solution. In a second experiment, donors were fed 20 or 40 μl, or until satiation, with 50% sucrose solution. There were significantly more trophallactic-giving contacts (TG) between donors fed 30% sucrose and their recipients than between donors fed 20% sucrose and their recipients, but no further increase was observed for higher concentrations. Increasing the volume fed to the donor bees, while keeping the concentration constant, led to an increase in TG. Analysis of the results from 61 assays involving 427 bees, shows that donor bees modify their trophallactic behaviour according to the sucrose concentration as well as the volume carried in their honey sacs. The role of food dist...

Bioconversion of sugarcane molasses into xanthan gum

A strain of Xanthomonas campestris E-NRC-3 was used for the production of xanthan gum from a medium based on cane sugar molasses. The effect of sugar concentration, fortification with different nitrogen sources and aeration rate on the yield of xanthan was investigated. The optimum conditions were 25% sugar in the medium, fortification with 2.4 g nitrogen per liter of ammonium chloride, air/medium ratio of 3:2 and 3 days of incubation at 30°C. Under these conditions the yield of xanthan gum by the used strain reached as high as 70.5 g l −1.

Thermodynamics of paracetamol solubility in sugar-water cosolvent systems

The solubility of paracetamol in different concentrations of sorbitol, glucose and sucrose solutions was studied at 20 and 37°C. There was an appreciable decrease in solubility of the drug at both temperatures, the effect generally being more apparent at the lower temperature as reflected by the solubility ratios. Sorbitol exhibited the greatest effect followed by glucose then sucrose. Thermodynamic parameters were calculated and showed the nonspontaneity of the solubility process (positive free energy values). Entropy changes were positive or of small negative values, while enthalpy changes were positive and of relatively small values. Such results are compatible with the occurrence of hydrophobic interactions that led to a reduction in the solubility of the antipyretic agent. However, the effect of sugar concentration on the thermodynamic parameters was not the same with the three sugars tested, suggesting differences in their solvency characteristics.

Effects of sugar concentrations on growth greening and shoot formation in callus cultures from four genetic lines of tobacco

Lowering the sucrose content in the medium causes a decrease in growth of tobacco callus cultures. At low sucrose concentrations the cultures developed a darker-green color, and produced a higher number of shoots in a shorter time. The shoots formed were of improved morphology. Our results might indicate that the osmolarity of the medium affects both greening and shoot formation in some tobacco callus cultures. Some differences were found between genetic lines in their responses to the shoot inducing media.

The activity of cell-wall degrading enzymes in tomato roots infected with Pyrenochaeta lycopersici and the effect of sugar concentrations in these roots on disease development

Cellulase and polygalacturonase, enzymes which degrade cell wall polysaccharides, showed negligible activity in healthy tomato roots but activity was at least 1·0 unit/g fresh weight in roots infected with Pyrenochaeta lycopersici. Other enzymes (α-galactosidase, β-glucosidase and β-xylosidase) which act on linkages in the cell wall structure were active in healthy roots but considerably more so in infected roots. Enzyme activities were usually greatest in lesion tissue or in tissue around the periphery of a lesion, and at a comparatively low concentration in the apparently healthy parts of infected roots. An attempt to control the progress of disease by decreasing the concentration of soluble sugars in infected roots was unsuccessful.