Production Of Fructose Research Articles

A green process for simultaneous production of fructose and ethanol via selective fermentation

Date (Phoenix dactylifera L.) fruits can provide a renewable source for the production of fructose and ethanol through selective fermentation processes. The effects of scale-up on ethanol yield and remaining fructose from date syrup in three 1 L, 7.5 L and 80 L fermentors were investigated. Fermentations were simultaneously conducted in the fermentors (working volume ratios of 1:10:100) using date syrups having an initial total sugars concentration of 142.5 g/L and Saccharomyces cerevisiae ATCC 36859 at 30 °C and 120 rpm. Experiments showed good and comparable results for the three fermentors. Glucose was completely consumed in the three fermentors. Fructose remained was 83.5%, 89.6% and 90.7% in the 1 L, 7.5 L and 80 L fermentors. The ethanol yields were 59.1%, 76.4% and 75.4%. The fructose fraction in the final syrup was >93% in the three fermentors. Statistically insignificant differences (p > 0.05) were obtained for the two larger fermentors. A kinetic model based on Monod equation was developed and successfully tested against the experimental data; also, the hydrodynamic was investigated using dimensionless correlations. A conceptual framework for the process was proposed. These results could provide a step forward towards commercialization of this clean process.

Glucose Isomerization by Enzymes and Chemo-catalysts: Status and Current Advances

The well-known interconversion of aldoses to their corresponding ketoses was discovered more than a century ago, but has recently attracted renewed attention due to alternative application areas. Since the pioneering discovery, much work has been directed toward improving the process of isomerization of aldoses in terms of yields, catalysts, solvents, catalytic systems, etc., by both enzymatic and chemo-catalytic approaches. Among aldose–ketose interconversion reactions, fructose production by glucose isomerization to make high-fructose corn syrup (HFCS) is an industrially important and large biocatalytic process today, and a large number of studies have been reported on the process development. In parallel, also alternative chemo-catalytic systems have emerged, as enzymatic conversion has drawbacks, though they are typically more selective and produce fructose under mild reaction conditions. Isomerization of glucose is also a central reaction for making renewable platform chemicals, such as lactic acid, ...

Identification of hexose kinase genes in Kluyveromyces marxianus and thermo-tolerant one step producing glucose-free fructose strain construction

In yeast, the hexose assimilation is started at hexose phosphorylation. However, in Kluyveromyces marxianus, the hexokinase (HXK) and glucokinase (GLK) genes were not identified by experiments. Meanwhile, the glucose-free fructose product requires more cost-efficient method. In this study, the KmHXK1 and KmGLK1 genes were functionally identified through gene disruption, over-expression and recombinant enzymes characterization. Both glucose and fructose assimilation ability decreased significantly in KmHXK1 disrupted strain YLM001, however, this ability was not changed obviously in KmGLK1 disrupted strain YLM002. When over-expressing KmGLK1 in YLM001, only the glucose assimilation ability was recovered in obtained strain (YLM005). The kinetic constant analysis of recombinant enzymes also proved that KmHXK1 could phosphorylate glucose (Vmax 553.01 U/mg, Km 0.83 mM) and fructose (Vmax 609.82 U/mg, Km 0.52 mM), and KmGLK1 only phosphorylate glucose with a Vmax of 0.73 U/mg and a Km 4.09 mM. A thermo-tolerant strain YGR003 which produced glucose-free fructose from Jerusalem artichoke tuber in one step was constructed based on the obtained information. The highest production and fastest productivity were 234.44 g/L and 10.26 g/L/h, respectively, which were several folds of the results in previous reports.

High lactic acid and fructose production via Mn2+-mediated conversion of inulin by Lactobacillus paracasei.

Lactobacillus paracasei DSM 23505 is able to produce high amounts of lactic acid (LA) by simultaneous saccharification and fermentation (SSF) of inulin. Aiming to obtain the highest possible amounts of LA and fructose, the present study is devoted to evaluate the impact of bivalent metal ions on the process of inulin conversion. It was shown that Mn2+ strongly increases the activity of the purified key enzyme β-fructosidase. In vivo, batch fermentation kinetics revealed that the high Mn2+ concentrations accelerated inulin hydrolysis by raise of the inulinase activity, and increased sugars conversion to LA through enhancement of the whole glycolytic flux. The highest LA concentration and yield were reached by addition of 15mM Mn2+-151g/L (corresponding to 40% increase) and 0.83g/g, respectively. However, the relative quantification by real-time reverse transcription assay showed that the presence of Mn2+ decreases the expression levels of fosE gene encoding β-fructosidase. Contrariwise, the full exclusion of metal ions resulted in fosE gene expression enhancement, blocked fructose transport, and hindered fructose conversion thus leading to huge fructose accumulation. During fed-batch with optimized medium and fermentation parameters, the fructose content reached 35.9% (w/v), achieving yield of 467g fructose from 675g inulin containing chicory flour powder (0.69g/g). LA received in course of the batch fermentation and fructose gained by the fed-batch are the highest amounts ever obtained from inulin, thus disclosing the key role of Mn2+ as a powerful tool to guide inulin conversion to targeted bio-chemicals.

The human brain produces fructose from glucose.

Fructose has been implicated in the pathogenesis of obesity and type 2 diabetes. In contrast to glucose, CNS delivery of fructose in rodents promotes feeding behavior. However, because circulating plasma fructose levels are exceedingly low, it remains unclear to what extent fructose crosses the blood-brain barrier to exert CNS effects. To determine whether fructose can be endogenously generated from glucose via the polyol pathway (glucose → sorbitol → fructose) in human brain, 8 healthy subjects (4 women/4 men; age, 28.8 ± 6.2 years; BMI, 23.4 ± 2.6; HbA1C, 4.9% ± 0.2%) underwent 1H magnetic resonance spectroscopy scanning to measure intracerebral glucose and fructose levels during a 4-hour hyperglycemic clamp (plasma glucose, 220 mg/dl). Using mixed-effects regression model analysis, intracerebral glucose rose significantly over time and differed from baseline at 20 to 230 minutes. Intracerebral fructose levels also rose over time, differing from baseline at 30 to 230 minutes. The changes in intracerebral fructose were related to changes in intracerebral glucose but not to plasma fructose levels. Our findings suggest that the polyol pathway contributes to endogenous CNS production of fructose and that the effects of fructose in the CNS may extend beyond its direct dietary consumption.

Protective role of fructokinase blockade in the pathogenesis of acute kidney injury in mice

Acute kidney injury is associated with high mortality, especially in intensive care unit patients. The polyol pathway is a metabolic route able to convert glucose into fructose. Here we show the detrimental role of endogenous fructose production by the polyol pathway and its metabolism through fructokinase in the pathogenesis of ischaemic acute kidney injury (iAKI). Consistent with elevated urinary fructose in AKI patients, mice undergoing iAKI show significant polyol pathway activation in the kidney cortex characterized by high levels of aldose reductase, sorbitol and endogenous fructose. Wild type but not fructokinase knockout animals demonstrate severe kidney injury associated with ATP depletion, elevated uric acid, oxidative stress and inflammation. Interestingly, both the renal injury and dysfunction in wild-type mice undergoing iAKI is significantly ameliorated when exposed to luteolin, a recently discovered fructokinase inhibitor. This study demonstrates a role for fructokinase and endogenous fructose as mediators of acute renal disease.

Cu-Induced [H6W12O42]6− polyoxometalate-based bimetallic cluster formation for renewable biomass inulin hydrolysis toward fructose production

Cu3[H6W12O42] cluster heterogeneous catalysts for inulin hydrolysis towards fructose production with 100% conversion and 90% selectivity under aqueous condition are achieved.

Continuous generation of fructose from Taraxacum officinale tap root extract and inulin by immobilized inulinase in a packed-bed reactor

Abstract Production of exo-inulinase from newly isolated Aspergillus niger was statistically optimized using dandelion tap root extract (% fresh w/v) resulting in a ~2.5 fold (2337 nkat/ml) enhancement. Exo-inulinase (1166 nkat/mg) immobilized in Ca-alginate beads was used for continuous generation of fructose from crude inulin extracted from Taraxacum officinale (dandelion) and chicory juice. Immobilized enzyme was optimally active at 50 °C and pH 5.0 and the kinetic parameters evaluated were 3.74 mM ( K m ) and 1.62 µm/min ( V max ). Continuous generation of fructose syrup from low-cost dandelion root extract and chicory inulin using a packed bed bioreactor prepared with exo-inulinase immobilized in alginate beads was demonstrated. Successive degradation of dandelion oligosaccharides and fructans to pure fructose was observed over 30 days period. The bioreactor had a half-life of 15 days and more than 90% (w/w) yield of fructose was observed. The study demonstrated use of a fructan-rich common weed for continuous production of fructose.

Produksi Fruktosa dari Tongkol Jagung Sebagai Gula Rendah Kalori

Corn cobs as waste organic agricultural having content±45% cellulose. Cellulose is a biopolymer that can be converted into glucose. Glucose can be produced by A.niger and T.ressei through fermentation process. Glucose in generate can be developed to become fructose syrup through a process isomerisasi with enzymes glucoisomerase prodused by Streptomyces Sp. This research using corn cobs yellow as a source of cellulose for the production of fructose. The purpose of this research is to find concentration fructose syrup obtained from fermentation process. Convertion cellulose be done in enzimatis use A.niger and T.ressei through the fermentation process by adding Saccharomyces cerevisiae. The process continues with isomerization use Streptomyces Sp. The process isomerization done with variations time is 1,2,3, and 4 hour and variation pH 6,7, and 8. Analysis concentration glucose and fructose of fermentation product performed with GCMS. The highest result obtained was fermentation 1 hour at pH 6 with glukoce 6,7% and fructose 16,22%.

The interaction of inulinase molecules with a chitosan matrix: UV-induced changes in the functional properties of immobilized inulinase

We have developed a technique for the immobilization of inulinase on chitosans with different molecular weights. The acid-soluble mid-molecular-weight (200 kDa) and high-molecular-weight (350 kDa) chitosans are shown to be promising matrices for inulinase adsorption. We assumed that the formation of an inulinase-chitosan matrix complex occurs mainly due to hydrophobic interactions; electrostatic interactions also play an essential role. The enzyme complex with high-molecular-weight chitosan is more stable against the action of UV light and temperature. This allows us to recommend chitosan as a catalyst in industry for the production of fructose from inulin-containing vegetable raw mateials.

Concomitant and discrete expressions of aldose reductase and sorbitol dehydrogenase in the male reproductive tract

This study aimed at investigating the expression and localization of the polyol pathway enzymes; aldose reductase (AR) and sorbitol dehydrogenase (SDH), in the male reproductive tract of rat. Gene expression analysis showed maximum expression of AR and SDH in the coagulating glands. Western blot analysis showed a coordinated presence of the two enzymes in the coagulating glands, seminal vesicle and epididymis. Immunohistochemistry showed a concordant expression of the two enzymes in the coagulating gland, which goes well with its function of fructose production in rats. A less concordant expression of the two enzymes in the seminal vesicle was also seen. Discrete expression of AR was seen in the Sertoli cells without SDH. Germ cells including sperm in the seminiferous tubules lacked AR, but SDH was present in all stages of developing germ cells including sperm present in the seminiferous tubules. The epithelial layer of epididymis showed the presence of AR, but it was negligible in vas deferens and prostate. SDH was not seen in the epithelial layer of epididymis, vas deferens or prostate. Though sperm in the seminiferous tubules lacked AR, sperm extracted from cauda showed the presence of both AR and SDH. Immunofluorescence localization of AR and SDH on sperm showed the presence of both the enzymes all over sperm. Discrete expression of AR in the Sertoli cells may be linked to detoxification of a number of metabolism by-products. Similarly, the presence of polyol enzymes on sperm in epididymis and beyond may be to tackle toxic metabolites they may encounter during their journey along the male or female reproductive tract.

Optimasi Produksi Inulinase oleh Khamir Pichia manshurica DUCC Y-015 pada Tepung Umbi Dahlia (Dahlia variabilis Willd.) dengan Variasi Konsentrasi K2HPO4 dan Waktu Inkubasi

Sugar national supply more and more decreases and can not meet the market needs. The research has been done to find alternative natural sweeteners including inulin from dahlia tubers (D. variabilis Willd). Dahlia tuber can produce 95% of yield of fructose syrup in an enzimatic reaction by inulinase (E.C.3.2.1.7). Inulinase is inductive enzyme that can be produce by P. manshurica. The production of fructose needs to be optimized to get optimum product. The optimization can be done by modifying the nutrient content in the medium such as K2HPO4 and variation of incubation time. The purpose of this study is to determine the concentration of K2HPO4 and optimum incubation time for P. manshurica. This research was conducted in Microbiology Laboratory, Biology Department, Faculty of Science and Mathematics Undip. The examined variable is the growth of yeast cell, inulinase activity, invertase, and the I/S ratio. This research was conducted experimentally using Randomized Complete Block Design (RCBD) factorial pattern with 2 factors, the first factor was the concentration of K2HPO4 (P), with concentration level (g/L) of 0.5 (P1), 1.0 (P2), and 1.5 (P3). The second factor was incubation time (W) with 12 hours (W12), 18 hours (W18), and 24 hours (W24). Every treatment was repeated three times. The collected data were analyzed using ANOVA. If there was a treatment effect, it will be continued with Duncan test on 5% significance level. The result of analysis show that the highest cell growth and the maximum production of inulinase enzyme was in P3W24 occurs in P3W24 (K2HPO4 1.5 g/L and 24 hours incubation time) treatment at 0.428 IU, but efficient in P1W12 treatment as much as 0.365 IU. Keywords: Dahlia variabilis Willd., Inulinase, K2HPO4, Pichia manshurica DUCC Y-015, incubation time

Metabolic acclimation of tetraploid and hexaploid wheats by cold stress-induced carbohydrate accumulation

Metabolic acclimation of plants to cold stress may be of great importance for their growth, survival and crop productivity. The accumulation carbohydrates associated with cold tolerance (CT), transcript levels for genes encoding related enzymes along with damage indices were comparatively studied in three genotypes of bread and durum wheats differing in sensitivity. Two (Norstar, bread wheat and Gerdish, durum wheat) were tolerant and the other, SRN (durum wheat), was susceptible to cold stress. During cold stress (−5°C for 24h), the contents of electrolyte leakage index (ELI) in Norstar and then Gerdish plants were lower than that of SRN plants, particularly in cold acclimated (CA) plants (4°C for 14days), confirming lethal temperature 50 (LT50) under field conditions. Increased carbohydrate abundances in the cases of sucrose, glucose, fructose, hexose phosphates, fructan, raffinose, arabinose resulted in different intensities of oxidative stress in bread (Norstar) plants compared to durum plants (SRN and Gerdish) plants as well as in CA plants compared to non-acclimated (NA) ones under cold, indicating metabolic/regulatory capacity along with a decrease in ELI content and enhanced defense activities. A significant decrease in these carbohydrates, particularly sucrose, under cold in NA plants showed an elevated level of cell damage (confirmed by ELI) compared to CA plants. On the other hand, an increase in hexose phosphates, particularly in NA plants, indicated sucrose degradation along with greater production of glucose and fructose compared to CA plants. Under such conditions, a significant increase in transcript levels of sucrose synthase and acidic invertase confirmed these results. Under cold, the high ABA-containing genotypes like Norstar and then Gerdish, which were obvious in CA plants, partly induced relative acclimation of cells for acquisition of CT compared to SRN. These results reveal an important role of carbohydrate metabolism in creating CT in durum wheats (particularly in Gerdish) as well as bread wheat with possible responsive components in metabolic and transcript levels.

Fructose production via extraction-assisted isomerization of glucose catalyzed by phosphates

Fructose presents a highly attractive substrate for future biorefineries for production of biofuels as well as bulk and fine chemicals.

5-hydroxymethylfurfural in bee feed

Classical beefeed is a concentrated sucrose solution that has to be freshly prepared by the beekeeper. Commercial bee feeds are invert sugar or starch syrups with added fructose that prevents cristallisation and keeps the bee feed fit for use for a longer period of time. During recent years, maximum levels of 5-hydroxymethyl-furfural (“HMF”), a conversion product of fructose are increasingly discussed. A comprehensive literature evaluation revealed that studies of the past were limited to a few publications on caged bees and that below 150 mg HMF/kg feed no adverse effects on bees were observed. In own outdoor trials under bee keeping conditions up to 150 mg HMF/kg of a fructose/invert sugar mixture were well tolerated. It can be assumed that the HMF tolerance of a feed depends on environmental conditions as well as the overall bee feed digestibility. From these data, no need for setting maximum levels of HMF in bee feed can be derived. The HMF content of bee feed increases temperature-dependent during storage and feeding. A limit between 20 and 40 mg HMF/kg feed syrup would prompt reformulations to ensure its compliance throughout the chain from production to the time of exposure to the bee. Accompanying measures (temperature control) would be needed throughout the chain. Reformulated bee feeds would need to be tested in pre-market trials under practical conditions in all European bee keeping climates to safely exclude other potential adverse effect of currently not predictable variables.

Rapid and efficient bioconversion of chicory inulin to fructose by immobilized thermostable inulinase from Aspergillus tubingensis CR16

Abstract Background Fructose, a monosaccharide, has gained wide applications in food, pharmaceutical and medical industries because of its favourable properties and health benefits. Biocatalytic production of fructose from inulin employing inulinase is the most promising alternative for fructose production. For commercial production, use of immobilized inulinase is advantageous as it offers reutilization of enzyme and increase in stability. In order to meet the demand of concentrated fructose syrup, inulin hydrolysis at high substrate loading is essential. Results Inulinase was immobilized on chitosan particles and employed for fructose production by inulin hydrolysis. Fourier transform infrared spectroscopy (FTIR) analysis confirmed linkage of inulinase with chitosan particles. Immobilized biocatalyst displayed significant increase in thermostability at 60 and 65 °C. Statistical model was proposed with an objective of optimizing enzymatic inulin hydrolytic process. At high substrate loading (17.5 % inulin), using 9.9 U/g immobilized inulinase at 60 °C in 12 h, maximum sugar yield was 171.1 ± 0.3 mg/ml and productivity was 14.25 g/l/h. Immobilized enzyme was reused for ten cycles. Raw inulin from chicory and asparagus was extracted and supplied in 17.5 % for enzymatic hydrolysis as a replacement of pure inulin. More than 70 % chicory inulin and 85 % asparagus inulin were hydrolyzed under optimized parameters at 60 °C. Results of high performance liquid chromatography confirmed the release of fructose after inulin hydrolysis. Conclusions The present findings prove potentiality of immobilized thermostable inulinase from Aspergillus tubingensis CR16 for efficient production of fructose syrup. Successful immobilization of inulinase on chitosan increased its stability and provided the benefit of enzyme reutilization. Box-Behnken design gave a significant model for inulin hydrolysis. Extraction of raw inulin from chicory and asparagus and their enzymatic hydrolysis using immobilized inulinase suggested that it can be a remarkable cost-effective process for large-scale fructose production.

Prospective Production of Fructose and Ethanol for Food and Fuel Markets by Selective Fermentation of Date Syrups

Sugars (fructose and glucose) in dates constitute about 75% of its dry weight. The effect of temperature and agitation on the production of fructose and ethanol from date syrups through selective fermentation of date syrups using S. cerevisiae ATCC 36858 was investigated in small-scale shake flask reactors. The ethanol production decreased with temperature due to the augmented inhibitory effect of ethanol at higher temperatures. The best temperature for cell growth was 33 C. At agitation speed of 160 rpm, ethanol productivity and specific growth were 0.97 g h-1 L-1 and 0.041 h-1, respectively, at 30 C. Fructose fractions produced here (>90%) were much higher than the commercial ones (42% and 55%); thus rendering the production of fructose from dates an economically viable process. The predictive character of Gompertz equation for ethanol production was extended by incorporating the temperature dependence of the parameters into the equation. Excellent fit was obtained with the extended equation in 27 C to 35 C.

Fructose Levels Are Markedly Elevated in Cerebrospinal Fluid Compared to Plasma in Pregnant Women

BackgroundFructose, unlike glucose, promotes feeding behavior in rodents and its ingestion exerts differential effects in the human brain. However, plasma fructose is typically 1/1000th of glucose levels and it is unclear to what extent fructose crosses the blood-brain barrier. We investigated whether local endogenous central nervous system (CNS) fructose production from glucose via the polyol pathway (glucose→sorbitol→fructose) contributes to brain exposure to fructose.MethodsIn this observational study, fasting glucose, sorbitol and fructose concentrations were measured using gas-chromatography-liquid mass spectroscopy in cerebrospinal fluid (CSF), maternal plasma, and venous cord blood collected from 25 pregnant women (6 lean, 10 overweight/obese, and 9 T2DM/gestational DM) undergoing spinal anesthesia and elective cesarean section.ResultsAs expected, CSF glucose was ~60% of plasma glucose levels. In contrast, fructose was nearly 20-fold higher in CSF than in plasma (p < 0.001), and CSF sorbitol was ~9-times higher than plasma levels (p < 0.001). Moreover, CSF fructose correlated positively with CSF glucose (ρ 0.45, p = 0.02) and sorbitol levels (ρ 0.75, p < 0.001). Cord blood sorbitol was also ~7-fold higher than maternal plasma sorbitol levels (p = 0.001). There were no differences in plasma, CSF, and cord blood glucose, fructose, or sorbitol levels between groups.ConclusionsThese data raise the possibility that fructose may be produced endogenously in the human brain and that the effects of fructose in the human brain and placenta may extend beyond its dietary consumption.

Investigation of the role of the calvin cycle and C1 metabolism during HCHO metabolism in gaseous HCHO-treated petunia under light and dark conditions using 13C-NMR.

It has been shown that formaldehyde (HCHO) absorbed by plants can be assimilated through the Calvin cycle or C1 metabolism. Our previous study indicated that Petunia hybrida could effectively eliminate HCHO from HCHO-polluted air. To understand the roles of C1 metabolism and the Calvin cycle during HCHO metabolism and detoxification in petunia plants treated with gaseous H(13)CHO under light and dark conditions. Aseptically grown petunia plants were treated with gaseous H(13)CHO under dark and light conditions. The metabolites generated from HCHO detoxification in petunia were investigated using (13)C-NMR. [2-(13)C]glycine (Gly) was generated via C1 metabolism and [U-(13)C]glucose (Gluc) was produced through the Calvin cycle simultaneously in petunia treated with low-level gaseous H(13)CHO under light conditions. Generation of [2-(13)C]Gly decreased whereas [U-(13) C]Gluc and [U-(13)C]fructose (Fruc) production increased greatly under high-level gaseous H(13)CHO stress in the light. In contrast, [U-(13)C]Gluc and [U-(13)C] Fruc production decreased greatly and [2-(13)C]Gly generation increased significantly under low-level and high-level gaseous H(13)CHO stress in the dark. C1 metabolism and the Calvin cycle contributed differently to HCHO metabolism and detoxification in gaseous H(13CHO-treated petunia plants. As the level of gaseous HCHO increased, the role of C1 metabolism decreased and the role of the Calvin cycle increased under light conditions. However, opposite changes were observed in petunia plants under dark conditions.

Novel insights into the mechanisms whereby isoflavones protect against fatty liver disease.

Fatty liver disease (FLD) is a growing public health problem worldwide. There is an urgent requirement for alternative and natural medicine to treat this disease. As phytochemicals, isoflavones have attracted considerable attention for the prevention of FLD. Numerous studies have revealed that isoflavones protect against FLD through various pathways which modulate fatty acid β-oxidation, lipid synthesis, and oxidative stress. Recently, the aldose reductase (AR)/polyol pathway has been reported to be involved in the development of FLD by modulating hepatic fructose production, peroxisome proliferator-activated receptor (PPAR)α activity, cytochrome P450 (CYP)2E1 expression, and gut bacterial endotoxin-induced cytokine release. It has been reported that some isoflavones are potent AR inhibitors. Here, we review the anti-FLD actions of isoflavones and the proposed mechanism whereby isoflavones protect against FLD, with regard to the AR/polyol pathway. We propose that isoflavones block the AR/polyol pathway and in turn reduce fructose production and subsequent fat accumulation in the liver in diabetic or high-glucose-diet mice. In addition, in rodents with alcoholic liver disease or nonalcoholic fatty liver disease/nonalcoholic steatohepatitis, inhibition of AR by isoflavones may improve PPARα-mediated fatty acid oxidation, reduce hepatic steatosis, and attenuate CYP2E1-mediated oxidative stress or AR/gut bacterial endotoxin-mediated cytokine overproduction, to alleviate progression of FLD.