It is of great significance to use biosynthesis to transform the inorganic substance formaldehyde into organic sugars. Most important in this process was to find a suitable catalyst combination to achieve the dimerization of formaldehyde. In a recent report, an engineered glycolaldehyde synthase was reported to catalyze this reaction. It could be combined with engineered D-fructose-6-phosphate aldolase, a "one-pot enzyme" method, to synthesize L-xylose using formaldehyde and the conversion rate could reach up to 64%. This process also provides a reference for the synthesis of other sugars. With the increasing consumption of non-renewable resources, it was of great significance to convert formaldehyde into sugar by biosynthesis.
Biocatalysis ; Formaldehyde ; chemistry ; Fructose-Bisphosphate Aldolase ; metabolism ; Xylose ; chemical synthesis

A mixture of fructose and glucose was developed to simulate the hydrolysate of Jerusalem artichoke tubers, the fructose-based feedstock suitable for butanol production. With the initial pH of 5.5 without regulation during mixed-sugar fermentation, as high as 23.26 g/L sugars were remained unconverted, and butanol production of 5.51 g/L were obtained. Compared with either glucose or fructose fermentation, the early termination of mixed-sugar fermentation might be caused by toxic organic acids and the low pH. When the pH of the fermentation system was controlled at higher levels, it was found that sugars utilization was facilitated, but less butanol was produced due to the over-accumulation of organic acids. On the other hand, when the pH was controlled at lower levels, more sugars were remained unconverted, although butanol production was improved. Based on these experimental results, a stage-wise pH regulation strategy, e.g., controlling the pH of the fermentation system at 5.5 untill the OD620 reached 1.0, and then the pH control was removed, was developed, which significantly improved the fermentation performance of the system, with only 2.05 g/L sugars unconverted and 10.48 g/L butanol produced.
Acetone ; metabolism ; Butanols ; metabolism ; Fermentation ; Fructose ; metabolism ; Glucose ; metabolism ; Helianthus ; metabolism ; Hydrogen-Ion Concentration

Enzymatic conversion is very important to produce functional rare sugars, but the conversion rate of single enzymes is generally low. To increase the conversion rate, a dual-enzyme coupled reaction system was developed. Dual-enzyme coupled reaction system was constructed using D-psicose-3-epimerase (DPE) and L-rhamnose isomerase (L-RhI), and used to convert D-fructose to D-psicose and D-allose. The ratio of DPE and L-RhI was 1:10 (W/W), and the concentration of DPE was 0.05 mg/mL. The optimum temperature was 60 degrees C and pH was 9.0. When the concentration of D-fructose was 2%, the reaction reached its equilibrium after 10 h, and the yield of D-psicose and D-allose was 5.12 and 2.04 g/L, respectively. Using the dual-enzymes coupled system developed in the current study, we could obtain sugar syrup containing functional rare sugar from fructose-rich raw material, such as high fructose corn syrup.
Aldose-Ketose Isomerases ; metabolism ; Carbohydrate Epimerases ; metabolism ; Fructose ; chemistry ; Glucose ; chemistry ; Hydrogen-Ion Concentration ; Temperature

Rare sugar is a kind of important low-energy monosaccharide that is rarely found in nature and difficult to synthesize chemically. D-allose, a six-carbon aldose, is an important rare sugar with unique physiological functions. It is radical scavenging active and can inhibit cancer cell proliferation. To obtain D-allose, the microorganisms deriving D-psicose 3-epimerase (DPE) and L-rhamnose isomerase (L-RhI) have drawn intense attention. In this paper, DPE from Clostridium cellulolyticum H10 was cloned and expressed in Bacillus subtilis, and L-RhI from Bacillus subtilis 168 was cloned and expressed in Escherichia coli BL21 (DE3). The obtained crude DPE and L-RhI were then purified through a HisTrap HP affinity chromatography column and an anion-exchange chromatography column. The purified DPE and L-RhI were employed for the production of rare sugars at last, in which DPE catalyzed D-fructose into D-psicose while L-RhI converted D-psicose into D-allose. The conversion of D-fructose into D-psicose by DPE was 27.34%, and the conversion of D-psicose into D-allose was 34.64%.
Aldose-Ketose Isomerases ; metabolism ; Bacillus subtilis ; enzymology ; Carbohydrate Epimerases ; metabolism ; Clostridium cellulolyticum ; enzymology ; Escherichia coli ; metabolism ; Fructose ; metabolism ; Glucose ; metabolism

Hereditary fructose intolerance (HFI) is a carbohydrate metabolic disease of autosomal recessive inheritance. The basic deficit is deficiency of aldolase B, the enzyme catalyzing catabolism of fructose-1-phosphate, which is found only in intestinal mucosa, liver and kidney. Its main symptoms are abdominal pain, vomiting, hypoglycemia, and severe liver disease following the ingestion of fructose. Neurologic impairment is not typical in HFI, but it can occur in the acute phase of the disease. Neurologic impairment is related to the acute hepatic toxicity of fructose (hypoglycemia, abnormal coagulation, cardiovascular collapse). The 7 year-old German girl admitted because of generalized tonic clonic seizure. She had the first seizure at the age of 2, and was diagnosed as Lennox-Gastaut syndrome. Thereafter, frequent morning and midnight seizures were developed following indigestion of milk, sweety cake and cookies. Her family history was unknown because she was adopted from India at the 4 months of age. She showed developmental delay. After the ingestion of fructose, the patient experienced hypoglycemic episode within 60-90 minutes of the intake. Based on this finding, she was diagnosed as HFI. With fructose free diet, the patient became free of seizure even without the anticonvulsant, and improved in growth and development.
Abdominal Pain ; Child ; Diet ; Dyspepsia ; Eating ; Female ; Fructose ; Fructose Intolerance* ; Fructose-Bisphosphate Aldolase ; Growth and Development ; Humans ; Hypoglycemia ; India ; Intestinal Mucosa ; Kidney ; Liver ; Liver Diseases ; Metabolic Diseases ; Metabolism ; Milk ; Seizures ; Vomiting ; Wills

STATEMENT OF PROBLEM: Streptococcus produces energy and forms extracellular polysaccharides by metabolizing sucrose. Insoluble glucan, a kind of extracellular polysaccharide, is the important material of dental plaque. Fructose affects the metabolism of sucrose. PURPOSE: The purpose of this study was to evaluate the effect of fructose on the metabolism of sucrose in Streptococcus mutans. MATERIALS AND METHODS: To determine the effect of fructose on the formation of artificial plaque by Streptococcus mutans Ingbritt, S. mutansand fructose were placed in beakers containing M17 broth and sucrose. The wires were hung on frameworks inserted into cork stoppers, and then immersed in each of the beakers. After the incubation with gentle shaking, each wire was weighed. To analyze the effect of fructose on the sucrose metabolism by S. mutans or glucosyltransferase, S. mutans and fructose were placed in M17 broth containing sucrose. After the incubation. the remaining sucrose and polymers were analysed by thin layer chromatography. RESULTS: The following results were obtained; 1. When Streptococcus mutans was cultured in the media containing 3% sucrose for 8 hours, the mean weight of formed artificial plaque on the wires was 124.3+/-3.0 mg, whereas being reduced to 20.7+/-10.2 mg in the media added with 3% sucrose and 4% fructose(p<0.05). 2. When the control containing glucose was added with sucrose, the optical density of Streptococcus mutans solution cultured for 24 hours was not increased compared with the control, while being increased by adding with fructose. 3. When Streptococcus mutanswas incubated in the media added with sucrose and fructose for 8 hours, the number of viable cells was increased compared with the media added with sucrose. 4. The amount of remained sucrose was increased in Streptococcus mutansculture supernatant of media added with sucrose and fructose than with sucrose only, but the amount of produced insoluble glucan was decreased. 5. The amounts of remained sucrose and produced soluble glucan were increased in the culture of glucosyltransferase-contained media added with sucrose and fructose than with sucrose only, but the amount of produced insoluble glucan was decreased. CONCLUSION: These results indicated that the sucrose metabolism and the production of insoluble glucan were inhibited in Streptococcus mutans by adding fructose in the media containing sucrose.
Chromatography, Thin Layer ; Dental Plaque ; Fructose* ; Glucose ; Metabolism* ; Polymers ; Polysaccharides ; Streptococcus mutans* ; Streptococcus* ; Sucrose*

STATEMENT OF PROBLEM: Streptococcus produces energy and forms extracellular polysaccharides by metabolizing sucrose. Insoluble glucan, a kind of extracellular polysaccharide, is the important material of dental plaque. Fructose affects the metabolism of sucrose. PURPOSE: The purpose of this study was to evaluate the effect of fructose on the metabolism of sucrose in Streptococcus mutans. MATERIALS AND METHODS: To determine the effect of fructose on the formation of artificial plaque by Streptococcus mutans Ingbritt, S. mutansand fructose were placed in beakers containing M17 broth and sucrose. The wires were hung on frameworks inserted into cork stoppers, and then immersed in each of the beakers. After the incubation with gentle shaking, each wire was weighed. To analyze the effect of fructose on the sucrose metabolism by S. mutans or glucosyltransferase, S. mutans and fructose were placed in M17 broth containing sucrose. After the incubation. the remaining sucrose and polymers were analysed by thin layer chromatography. RESULTS: The following results were obtained; 1. When Streptococcus mutans was cultured in the media containing 3% sucrose for 8 hours, the mean weight of formed artificial plaque on the wires was 124.3+/-3.0 mg, whereas being reduced to 20.7+/-10.2 mg in the media added with 3% sucrose and 4% fructose(p<0.05). 2. When the control containing glucose was added with sucrose, the optical density of Streptococcus mutans solution cultured for 24 hours was not increased compared with the control, while being increased by adding with fructose. 3. When Streptococcus mutanswas incubated in the media added with sucrose and fructose for 8 hours, the number of viable cells was increased compared with the media added with sucrose. 4. The amount of remained sucrose was increased in Streptococcus mutansculture supernatant of media added with sucrose and fructose than with sucrose only, but the amount of produced insoluble glucan was decreased. 5. The amounts of remained sucrose and produced soluble glucan were increased in the culture of glucosyltransferase-contained media added with sucrose and fructose than with sucrose only, but the amount of produced insoluble glucan was decreased. CONCLUSION: These results indicated that the sucrose metabolism and the production of insoluble glucan were inhibited in Streptococcus mutans by adding fructose in the media containing sucrose.
Chromatography, Thin Layer ; Dental Plaque ; Fructose* ; Glucose ; Metabolism* ; Polymers ; Polysaccharides ; Streptococcus mutans* ; Streptococcus* ; Sucrose*

To demonstrate the fructose metabolism pathway in Bifidobacterium Longum NCC2705 and to construct its fermentation model, we explored the comparative proteome cultivating the strain on glucose or fructose, based on a proteomic reference map of B. longum NCC2705 constructed earlier. Then, we used matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and electro-spray ionization tandem mass spectrometry (ESI-MS/MS) for differently expressed proteins identification. Furthermore, with semi-quantitative RT-PCR we determined the distinctively expressed proteins at the level of transcription. Proteomic comparison of glucose- and fructose-grown cells demonstrated much similarity. On the page of fructose there were all the enzymes and proteins that exist during the process of glucose degradation. We observed a greater variation of more than three-fold for the identified 9 spots representing 5 protein entries by MALDI-TOF MS. The sugar-binding protein specific to fructose (BL0033) and an ABC transporter ATP binding protein (BL0034) showed higher expression level from cells grown on fructose. It was also determined by semi-quantitative RT-PCR subsequently. BL0033 time course and concentration experiments showed that the induction time correlated to higher fructose concentration, and increased expression of BL0033. Fructose was catabolized via the same degradation pathway as glucose at the level of proteomics. BL0033 was induced by fructose. All results suggest that the uptake of fructose into the cell may be conducted by a specific ABC transport system, in which BL0033 and BL0034 as components might have played an important role.
Bifidobacterium ; chemistry ; genetics ; metabolism ; Culture Media ; Fermentation ; Fructose ; pharmacology ; Glucose ; pharmacology ; Proteome ; analysis ; genetics ; Proteomics ; methods

Excessive fructose intake is related to a high prevalence of metabolic syndrome, while little attention has been paid to the impact of maternal high-fructose (HF) intake on the development of metabolic syndrome and organ-specific transcriptome alterations in the offspring. We utilized RNA next-generation sequencing (NGS) technology to analyze the transcriptome expression in four organs (kidney, brain, heart, and urinary bladder) from 1-day, 3-week, and 3-month-old male offspring exposed to maternal HF diet. Maternal HF induced various phenotypes of metabolic syndrome in adult male offspring. We observed that maternal HF exposure induces long-term alterations of gene expression in the brain, heart, kidney, and urinary bladder in adult offspring. Different organs do not respond similarly to maternal HF intake. We found that changes in expression of Errfi1 and Ctgf were shared by four organs at 1 day of age. Also, a number of genes regulating fructose metabolism, glycolysis/gluconeogenesis, fatty acid metabolism, and insulin signalling appear to be regulated by maternal HF intake in different organs at 1 day of age. Our NGS results are of significance to the development of maternal interventions in the prevention of maternal HF-induced organ-specific programming, in order to reduce the global burden of metabolic syndrome.
Animals ; Female ; Fructose ; Kidney ; Lipid Metabolism ; Male ; Metabolic Syndrome ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Transcriptome

Our previous work has indicated that mycelium growth and exopolysaccharide accumulation in submerged fermentation by Pholiota squarrosa (Pers. ex Fr.) Quel. AS 5.245 are strongly affected by many internal and external factors, including medium constituents and fermentation conditions. In this study, we use an effective two-phase statistical approach to enhance exopolysaccharide production. In the first phase, Plackett-Burman design was undertaken to evaluate the effects of the twenty factors, i.e., glucose, fructose, maltose, yeast extract, tryptone, K2HPO4, KH2PO4, (NH4)2SO4, NaNO3, FeSO4, MgSO4, MnCl2, ZnCl2, FeCl3, CuSO4.5H2O, vitamin B1, initial pH, the temperature, the medium volume and the duration, to the fermentation. By regression analysis, yeast extract, tryptone, fructose, MgSO4, MnCl2, initial pH and temperature were found to be important for exopolysaccharide production, while glucose, maltose, NaNO3, ZnCl2, vitamin B1, the duration and the volume are important to the mycelium biomass. In the second phase of the optimization process, a response surface methodology (RSM) was used to optimize the above critical internal factors, and to find out the optimal concentration levels and the relationships between these factors. Based on the results of the first phase, a five-level six-factor (yeast extract, fructose, MgSO4, maltose, ZnCl2 and initial pH) central composite rotatable design (CCRD) was employed. By solving the quadratic regression model equation using appropriate statistic methods, the optimal concentrations for obtaining 876.32 microg exopolysaccharide per milliliter of fermentation liquor were calculated as: 6.0g/L yeast extract, 11.5g/L fructose, 0.5g/L MgSO4, 9.6g/L maltose, 38.6mg/L ZnCl2 and with the initial pH 5.3. The experimental data under various conditions have validated the theoretical values.
Culture Media ; Fermentation ; Fructose ; metabolism ; Hydrogen-Ion Concentration ; Maltose ; metabolism ; Pholiota ; growth & development ; metabolism ; Polysaccharides ; analysis ; biosynthesis ; Temperature