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1.
International Journal of Traditional Chinese Medicine ; (6): 689-693, 2023.
Article in Chinese | WPRIM | ID: wpr-989689

ABSTRACT

Objective:To evaluate the efficacy of self-made Xiaogan Tiaopi Kaiwei Decoction combined with conventional western medicine therapy in the treatment of infantile anorexia of spleen-stomach weakness.Methods:Randomized controlled trial. A total of 100 children with anorexia of spleen-stomach weakness ,who were treated in the First Clinical Medical College of Shaanxi University of Chinese Medicine between April 2020 and September 2021, were selected as the observation subjects in a prospective cohort study, and they were divided into two groups by the random number table method, with 50 in each group. The control group was given routine treatment, and the Traditional Chinese Medicine (TCM) group was given self-made Xiaogan Tiaopi Kaiwei Decoction on the basis of the control group. The TCM syndromes were scored before and after treatment. The levels of trace elements such as iron, zinc and calcium were detected by atomic spectrometer, the absorptivity of D-xylose was measured by colorimetry. The adverse events during treatment were recorded. After 6 months of follow-up, the height, weight and BMI were measured and recorded, and the clinical efficacy was assessed.Results:The total response rate was 96.0% (48/50) in the TCM group and that in the control group was 84.0% (42/50) ( χ2=4.00, P=0.046). The scores of decreased appetite, anorexia, sallow complexion, abdominal fullness and distention and shortness of breath and laziness to speak and total score in the TCM group after treatment were significantly lower than those in the control group ( t=12.47, 13.42, 14.19, 16.39, 9.15, 17.72, P<0.01). The levels of blood trace elements such as iron [(414.58 ± 57.52) mg/L vs. (350.85 ± 53.33) mg/L, t=5.75 ], zinc [(8.26 ± 1.55) mg/L vs. (7.64 ± 1.37) mg/L, t=2.12 ] and calcium [(77.26 ± 15.30) mg/L vs. (71.05±14.26) mg/L, t=2.10] and urine D-xylose absorption rate [(31.76±5.28) % vs. (27.97 ± 4.61) %, t=3.82 ] in the TCM group were significantly higher than those in the control group ( P<0.01 or P<0.05). During treatment, there was no serious adverse reaction in the TCM group and 1 case of nausea in the control group. There was no statistical significance in the incidence rate of adverse reactions between the two groups ( χ2=1.01, P=0.315). After follow-up, the weight in the TCM group was significantly higher than that of the control group ( t=2.17, P=0.032). Conclusion:Self-made Xiaogan Tiaopi Kaiwei Decoction combined with conventional western medicine therapy can relieve the clinical symptoms, promote the absorption of trace elements and improvement of spleen-stomach function, and enhance the long-term efficacy in the treatment of children with anorexia of spleen-stomach weakness, and it has no adverse reactions.

2.
Chinese Journal of Biotechnology ; (12): 1042-1057, 2021.
Article in Chinese | WPRIM | ID: wpr-878613

ABSTRACT

Effective utilization of xylose is a basis for economic production of biofuels or chemicals from lignocellulose biomass. Over the past 30 years, through metabolic engineering, evolutionary engineering and other strategies, the metabolic capacity of xylose of the traditional ethanol-producing microorganism Saccharomyces cerevisiae has been significantly improved. In recent years, the reported results showed that the transcriptome and metabolome profiles between xylose and glucose metabolism existed significant difference in recombinant yeast strains. Compared with glucose, the overall process of xylose metabolism exhibits Crabtree-negative characteristics, including the limited glycolytic pathway activity, which reduces the metabolic flux of pyruvate to ethanol, and the enhanced cytosolic acetyl-CoA synthesis and respiratory energy metabolism. These traits are helpful to achieve efficient synthesis of downstream products using pyruvate or acetyl-CoA as precursors. This review provides a detailed overview on the modification and optimization of xylose metabolic pathways in S. cerevisiae, the characteristics of xylose metabolism, and the construction of cell factories for production of chemicals using xylose as a carbon source. Meanwhile, the existed difficulties and challenges, and future studies on biosynthesis of bulk chemicals using xylose as an important carbon source are proposed.


Subject(s)
Biofuels , Ethanol , Fermentation , Metabolic Engineering , Saccharomyces cerevisiae/genetics , Xylose
3.
Chinese Journal of Biotechnology ; (12): 196-206, 2021.
Article in Chinese | WPRIM | ID: wpr-878554

ABSTRACT

Polyhydroxyalkanoates (PHAs) have obtained much attention in biomaterial fields due to their similar physicochemical properties to those of the petroleum-derived plastics. Poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] is one member of the PHAs family, and has better toughness and transparency compared to existing polylactic acid (PLA) and poly[(R)-3-hydroxybutyrate] [P(3HB)]. First, we confirmed the one-step biosynthesis of P(LA-co-3HB) with the lactate fraction of 23.8 mol% by introducing P(3HB-co-LA) production module into Escherichia coli MG1655. Then, the lactate fraction was increased to 37.2 mol% in the dld deficient strain WXJ01-03. The genes encoding the thioesterases, ydiI and yciA, were further knocked out, and the lactate fraction in the P(3HB-co-LA) was improved to 42.3 mol% and 41.1 mol% respectively. Strain WXJ03-03 with dld, ydiI and yciA deficient was used for the production of the LA-enriched polymer, and the lactate fraction was improved to 46.1 mol%. Notably, the lactate fraction in P(3HB-co-LA) from xylose was remarkably higher than from glucose, indicating xylose as a potent carbon source for P(3HB-co-LA) production. Therefore, the deficiency of thioesterase may be considered as an effective strategy to improve the lactate fraction in P(3HB-co-LA) in xylose fermentation.


Subject(s)
Escherichia coli/genetics , Hydroxybutyrates , Lactic Acid , Polyesters , Polyhydroxyalkanoates , Xylose
4.
Chinese Journal of Biotechnology ; (12): 942-948, 2020.
Article in Chinese | WPRIM | ID: wpr-826882

ABSTRACT

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.


Subject(s)
Biocatalysis , Formaldehyde , Chemistry , Fructose-Bisphosphate Aldolase , Metabolism , Xylose
5.
Braz. arch. biol. technol ; 62: e19180728, 2019. tab, graf
Article in English | LILACS | ID: biblio-1055382

ABSTRACT

Abstract The biological assimilation of the sugars present in lignocellulosic residues has gained prominence since these residues are the most abundant and economic residues in nature. Thus, the objective of this work was to determine whether the use of D-xylose and L-arabinose as sources of carbon in Synechococcus nidulans and Spirulina paracas cultures affects the growth and production of proteins and carbohydrates. Kinetic growth parameters, pentose consumption, protein content and carbohydrates were evaluated. Synechococcus nidulans and Spirulina paracas consumed all concentrations of pentose used. The highest cellular concentration (1.37 g.L-1) and the highest protein productivity (54 mg.L-1.d-1) were obtained for Spirulina paracas, which was submitted to the addition of 38.33 mg.L-1 D-xylose and 1.79 mg.L-1 L-arabinose. The use of pentose promoted the accumulation of proteins for the studied microalgae. This is one of the first works to report protein bioaccumulation as a result of pentose addition.


Subject(s)
Arabinose/administration & dosage , Xylose/administration & dosage , Carbohydrates , Proteins/drug effects , Synechococcus
6.
Chinese Journal of Biotechnology ; (12): 254-262, 2019.
Article in Chinese | WPRIM | ID: wpr-771381

ABSTRACT

Escherichia coli was metabolically engineered to produce poly(glycolate-co-lactate-co-3-hydroxybutyrate) using glucose and xylose as carbon sources. The combinatorial biosynthetic route was constructed by the overexpression of a series of enzymes including D-tagatose 3-epimerase, L-fuculokinase, L-fuculose-phosphate aldolase, aldehyde dehydrogenase, propionyl-CoA transferase, β-ketothiolase, acetoacetyl-CoA reductase, and polyhydroxyalkanoate synthase. Overexpression of polyhydroxyalkanoate granule associated protein significantly improved biopolymer synthesis, and the recombinant strain reached 3.73 g/L cell dry weight with 38.72% (W/W) biopolymer content. A co-culture engineering strategy was developed to produce biopolymer from a mixture of glucose and xylose, achieving 4.01 g/L cell dry weight containing 21.54% (W/W) biopolymer. The results of this work offer an approach for simultaneously utilizing glucose and xylose and indicate the potential for future biopolymer production from lignocellulosic biomass.


Subject(s)
3-Hydroxybutyric Acid , Escherichia coli , Glucose , Glycolates , Lactates , Metabolic Engineering , Polyesters , Xylose
7.
Chinese Traditional and Herbal Drugs ; (24): 3107-3112, 2019.
Article in Chinese | WPRIM | ID: wpr-851018

ABSTRACT

Objective: To compare the effects of Hedysari Radix and Hedysari Radix Praeparata Cum Melle in Buzhong Yiqi and its chemical composition, and preliminarily reveal the mechanism of Hedysari Radix processed with honey. Methods: A rat model of spleen qideficiency was established. The rats were treated with different doses of water extracts of Hedysari Radix and Hedysari Radix Praeparata Cum Melle and the content of serum D-xylose, GAS, IL-2, TNF-α were used as indicators to study the differences in the efficacy of Hedysari Radix and Hedysari Radix Praeparata Cum Melle in Buzhong Yiqi. Based on HPLC techniques, the different components in methanol extract of Hedysari Radix and Hedysari Radix Praeparata Cum Melle were analyzed. Results: Compared with the blank group, the serum xylose, gastrin content in the model group were significantly decreased. Compared with the model group, except for the low dose group of Hedysari Radix, the serum xylose, and gastrin content of the rats in each administration group were significantly increased (P < 0.01), and the results in the middle dose group of Hedysari Radix were significantly higher than those in the middle dose group of Hedysari Radix Praeparata Cum Melle (P < 0.05, P < 0.01). Compared with the blank group, the serum IL-2 and TNF-α levels in the model group were significantly increased (P < 0.01). Compared with the model group, the serum IL-2 and TNF-α levels in the rats in each drug group were significantly decreased (P < 0.05, P < 0.01); Compared with the medium dose group of Hedysari Radix, the serum IL-2 and TNF-α levels in the medium dose group of honey-processing Hedysari Radix were significantly decreased (P < 0.05, P < 0.01). There were differences in the chromatographic peaks in the fingerprints of Hedysari Radix and Hedysari Radix Praeparata Cum Melle. Conclusion: Both Hedysari Radix and Hedysari Radix Praeparata Cum Melle can significantly intervene and improve the syndrome of spleen qi deficiency in rats and the pharmacodynamics effect of Hedysari Radix Praeparata Cum Melle is better than that of Hedysari Radix. There are differences in the components of Hedysari Radix and Hedysari Radix Praeparata Cum Melle and these differences may be the active substances that cause differences in the efficacy.

8.
Food Sci. Technol (SBCTA, Impr.) ; 38(1): 126-133, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-892256

ABSTRACT

Abstract Morchella esculenta (L) Pers. is a highly valued edible and medicinal fungus that remains underutilized. For this study, the effects of glycation treatment on antioxidant activity and characteristics of the M. esculenta protein isolate (MPI) were investigated via the Maillard reaction. Conjugation between MPI and xylose was proven via UV-vis, FT-IR, intrinsic fluorescence analysis, and SDS-PAGE. Amino acid analysis revealed involvement of lysine, arginine and tyrosine in MPI, forming a covalent cross-link with xylose. Differential scanning calorimetry (DSC) results showed that glycated MPI (MPIG) possesses a more favorable thermal stability compared to native MPI (MPIN), heated MPI (MPIH) and an unheated mixture of MPI and xylose (MPI-XM). MPIG exhibited significantly enhanced antioxidant activity compared to MPIN, MPIH, and MPI-XM. These results indicate MPIG can serve as a promising novel source of nutraceutical and functional ingredients that exert antioxidant activity.

9.
Braz. j. microbiol ; 49(1): 162-168, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889200

ABSTRACT

ABSTRACT For the implementation of cellulosic ethanol technology, the maximum use of lignocellulosic materials is important to increase efficiency and to reduce costs. In this context, appropriate use of the pentose released by hemicellulose hydrolysis could improve de economic viability of this process. Since the Saccharomyces cerevisiae is unable to ferment the pentose, the search for pentose-fermenting microorganisms could be an alternative. In this work, the isolation of yeast strains from decaying vegetal materials, flowers, fruits and insects and their application for assimilation and alcoholic fermentation of xylose were carried out. From a total of 30 isolated strains, 12 were able to assimilate 30 g L-1 of xylose in 120 h. The strain Candida tropicalis S4 produced 6 g L-1 of ethanol from 56 g L-1 of xylose, while the strain C. tropicalis E2 produced 22 g L-1 of xylitol. The strains Candida oleophila G10.1 and Metschnikowia koreensis G18 consumed significant amount of xylose in aerobic cultivation releasing non-identified metabolites. The different materials in environment were source for pentose-assimilating yeast with variable metabolic profile.


Subject(s)
Pentoses/metabolism , Xylose/metabolism , Yeasts/metabolism , Vegetables/microbiology , Xylitol/metabolism , Yeasts/isolation & purification , Yeasts/classification , Yeasts/genetics , Ethanol/metabolism , Fermentation
10.
Electron. j. biotechnol ; 31: 67-54, Jan. 2018. ilus, tab, graf
Article in English | LILACS | ID: biblio-1022118

ABSTRACT

Background: Pretreatment of lignocellulosic biomass is essential for using it as a raw material for chemical and biofuel production. This study evaluates the effects of variables in the chemical pretreatment of the Arundo biomass on the glucose and xylose concentrations in the final enzymatic hydrolysate. Three pretreatments were tested: acid pretreatment, acid pretreatment followed by alkaline pretreatment, and alkaline pretreatment. Results: The amounts of glucose and xylose released by the enzymatic hydrolysis of the Arundo biomass obtained from acid pretreatment ranged from 6.2 to 19.1 g/L and 1.8 to 3.1 g/L, respectively. The addition of alkaline pretreatment led to a higher yield from the enzymatic hydrolysis, with the average glucose concentration 3.5 times that obtained after biomass hydrolysis with an acid pretreatment exclusively. The use of an alkaline pretreatment alone resulted in glucose and xylose concentrations similar to those obtained in the two-step pretreatment: acid pretreatment followed by alkaline pretreatment. There was no significant difference in 5-hydroxymethylfurfural, furfural, or acetic acid concentrations among the pretreatments. Conclusion: Alkaline pretreatment was essential for obtaining high concentrations of glucose and xylose. The application of an alkaline pretreatment alone resulted in high glucose and xylose concentrations. This result is very significant as it allows a cost reduction by eliminating one step.


Subject(s)
Ethanol/metabolism , Poaceae/chemistry , Acids/chemistry , Xylose/analysis , Cellulose/chemistry , Biomass , Biofuels , Glucose/analysis , Hydrolysis , Lignin
11.
Malaysian Journal of Microbiology ; : 372-380, 2018.
Article in English | WPRIM | ID: wpr-750429

ABSTRACT

Aims@#The implementation of simultaneous saccharification and co-fermentation (SScF) and consolidated bioprocessing (CBP) is highly anticipated for industrial bioethanol applications. Thus, microorganisms capable of utilizing hexose and pentose sugars, as well as thermotolerant, are considered advantageous for optimum ethanol production.@*Methodology and results@#Thermotolerant yeast strains were isolated from wastewater ponds of ethanol-producing facility as well as empty fruit bunch composting area and screened for xylose- and glucose-fermenting ability. Five out of 24 total isolates were able to grow at 40 ºC and were found positive for ethanol production from xylose. Based on their high efficiency of xylose and glucose utilization, two isolates were chosen for further characterization. They were identified as Kluyveromyces marxianus UniMAP 1-1 and Schwanniomyces etchellsii UniMAP 1-7 based on the D1/D2 region of the large subunit ribosomal DNA. The growth kinetics of each isolate on xylose and glucose at 40 °C were determined. The two isolates were able to ferment xylose to ethanol at a maximum concentration between 0.533  0.415 and 1.243  0.246 g/L with concomitant xylitol production between 9.932  0.303 and 12.933  0.505 g/L. Fermentation of glucose to ethanol was also tested for these isolates and the yields were and 0.361 and 0.118 g/g for UniMAP 1-1 and UniMAP 1-7, respectively.@*Conclusion, significance and impact of study@#The potential of these thermotolerant microbes to be used for xylitol and bioethanol production from lignocelluloses are evident from this study.

12.
Chinese Traditional and Herbal Drugs ; (24): 5843-5848, 2018.
Article in Chinese | WPRIM | ID: wpr-851481

ABSTRACT

Objective To compare the effects of prepared Rehmanniae Radix Praparata (RRP) on gastrointestinal motility in rats with purgation with bitter cold and excessive fatigue type spleen deficiency. Methods A total of 80 SD rats were randomly divided into eight groups according to their body weights, which named as control group, model group, nine steamed nine sunned RRP group (RRP ), nine steamed nine sunned (without yellow wine) RRP group (RRP Ⅱ group), nine steamed nine sunned (without Amomi Fructus) RRP group (RRP III group), nine steamed nine sunned (without yellow wine and Amomi Fructus) RRP group (RRP IV group), steamed RRP group (RRP V group), and wine stewed RRP group (VI group). By filling the rats with Rhei Radix et Rhizoma decoction and swimming 2 to 5 min at the same time, with its body sinking as degree, once daily, after obtaining the model of purgation with bitter cold and excessive fatigue type spleen deficiency of the RRP groups I-VI, the spleen deficiency rats’ general physical signs were observed, and the serum D-xylose, GAS, and MTL of the spleen asthenia rats were measured. The effects of different processed products of RRP on gastrointestinal digestion and absorption and intestinal propulsion in rats with spleen deficiency were observed. Results The weight, food intake, and influent amount of model rats were significantly increased after nine steamed and nine sunned RRP treatment (P < 0.01), while the weight, food intake, and water intake of the rats in RRP V and VI groups after administration were decreased compared with the model rats (P < 0.05). By measuring the intestinal propulsion rate, D-xylose, GAS, and MTL content in the serum, the intestinal propulsive rate, the serum D-xylose, GAS, and MTL content of the rats in RRP III, IV, V, and groups were lower than those of the control group (P < 0.01). The intestinal propulsive rate and the content of serum D-xylose in the RRP V group and RRP VI group were lower than that in the RRP group (P < 0.01). The intestinal propulsive rate and the serum D-xylose content in rats of RRP IV group were lower than those in the RRP group (P < 0.05). The serum GAS and MTL content in rats of RRP IV group were lower than those in the RRP group (P < 0.01). Conclusion Nine steamed nine sunned processing method can effectively alleviate the disadvantages of RRP because of its strong flavor and rich spleen.

13.
Braz. j. microbiol ; 48(4): 648-655, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-889169

ABSTRACT

ABSTRACT Producing biofuels such as ethanol from non-food plant material has the potential to meet transportation fuel requirements in many African countries without impacting directly on food security. The current shortcomings in biomass processing are inefficient fermentation of plant sugars, such as xylose, especially at high temperatures, lack of fermenting microbes that are able to resist inhibitors associated with pre-treated plant material and lack of effective lignocellulolytic enzymes for complete hydrolysis of plant polysaccharides. Due to the presence of residual partially degraded lignocellulose in the gut, the dung of herbivores can be considered as a natural source of pre-treated lignocellulose. A total of 101 fungi were isolated (36 yeast and 65 mould isolates). Six yeast isolates produced ethanol during growth on xylose while three were able to grow at 42 °C. This is a desirable growth temperature as it is closer to that which is used during the cellulose hydrolysis process. From the yeast isolates, six isolates were able to tolerate 2 g/L acetic acid and one tolerated 2 g/L furfural in the growth media. These inhibitors are normally generated during the pre-treatment step. When grown on pre-treated thatch grass, Aspergillus species were dominant in secretion of endo-glucanase, xylanase and mannanase.


Subject(s)
Animals , Ethanol/metabolism , Fungi/isolation & purification , Fungi/metabolism , Manure/microbiology , Biofuels/analysis , Biofuels/microbiology , Fermentation , Fungi/classification , Fungi/genetics , Herbivory , Lignin/metabolism , Manure/analysis , Plants/metabolism , Xylose/metabolism
14.
Braz. j. microbiol ; 48(4): 791-800, Oct.-Dec. 2017. graf
Article in English | LILACS | ID: biblio-889166

ABSTRACT

ABSTRACT Lignocellulose-derived inhibitors have negative effects on the ethanol fermentation capacity of Saccharomyces cerevisiae. In this study, the effects of eight typical inhibitors, including weak acids, furans, and phenols, on glucose and xylose co-fermentation of the recombinant xylose-fermenting flocculating industrial S. cerevisiae strain NAPX37 were evaluated by batch fermentation. Inhibition on glucose fermentation, not that on xylose fermentation, correlated with delayed cell growth. The weak acids and the phenols showed additive effects. The effect of inhibitors on glucose fermentation was as follows (from strongest to weakest): vanillin > phenol > syringaldehyde > 5-HMF > furfural > levulinic acid > acetic acid > formic acid. The effect of inhibitors on xylose fermentation was as follows (from strongest to weakest): phenol > vanillin > syringaldehyde > furfural > 5-HMF > formic acid > levulinic acid > acetic acid. The NAPX37 strain showed substantial tolerance to typical inhibitors and showed good fermentation characteristics, when a medium with inhibitor cocktail or rape straw hydrolysate was used. This research provides important clues for inhibitors tolerance of recombinant industrial xylose-fermenting S. cerevisiae.


Subject(s)
Saccharomyces cerevisiae/drug effects , Xylose/metabolism , Glucose/metabolism , Phenols/metabolism , Phenols/pharmacology , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Acids/metabolism , Acids/pharmacology , Industrial Microbiology , Fermentation , Furans/metabolism , Furans/pharmacology
15.
Chinese Journal of Biotechnology ; (12): 923-935, 2017.
Article in Chinese | WPRIM | ID: wpr-242218

ABSTRACT

Kluyveromyces marxianus, as unconventional yeast, attracts more and more attention in the biofuel fermentation. Although this sort of yeasts can ferment pentose sugars, the fermentation capacity differs largely. Xylose and arabinose fermentation by three K. marxianus strains (K. m 9009, K. m 1911 and K. m 1727) were compared at different temperatures. The results showed that the fermentation performance of the three strains had significant difference under different fermentation temperatures. Especially, the sugar consumption rate and alcohol yield of K. m 9009 and K. m 1727 at 40 ℃ were better than 30 ℃. This results fully reflect the fermentation advantages of K. marxianus yeast under high-temperature. On this basis, five genes (XR, XDH, XK, AR and LAD) coding key metabolic enzymes in three different yeasts were amplified by PCR, and the sequence were compared by Clustalx 2.1. The results showed that the amino acid sequences coding key enzymes have similarity of over 98% with the reference sequences reported in the literature. Furthermore, the difference of amino acid was not at the key site of its enzyme, so the differences between three stains were not caused by the gene level, but by transcribed or translation regulation level. By real-time PCR experiment, we determined the gene expression levels of four key enzymes (XR, XDH, XK and ADH) in the xylose metabolism pathway of K. m 1727 and K. m 1911 at different fermentation time points. The results showed that, for thermotolerant yeast K. m 1727, the low expression level of XDH and XK genes was the main factors leading to accumulation of xylitol. In addition, according to the pathway of Zygosaccharomyces bailii, which have been reported in NCBI and KEGG, the xylose and arabinose metabolic pathways of K. marxianus were identified, which laid foundation for further improving the pentose fermentation ability by metabolic engineering.

16.
Chinese Journal of Biotechnology ; (12): 692-698, 2017.
Article in Chinese | WPRIM | ID: wpr-310622

ABSTRACT

Bacillus subtilis is Gram-positive aerobic bacterium and widely used as a heterologous protein expression host because of its safety and high protein secretion property. However, comparing to Escherichia coli, the low transformation efficiency limits the application of B. subtilis as a host cell for directed evolution of heterologous enzymes. Therefore, we optimized the competent cell preparation conditions for conventional plasmid, including the alteration of the medium, the concentration of inducer, the plasmid type, and other parameters. Compared with the original LB medium, YN medium improved the transformation efficiency by about 4 folds. The transformation efficiency enhanced by about 2 folds under induction with 1.5% xylose for 2 h. In addition, with plasmids prepared from E. coli GM272 strain the transformation efficiency increased by about 3 folds. Combining all these findings, the transformation efficiency of pDG1730 plasmid under the optimized conditions could reach 10⁶ CFU/μg, which was 2 orders of magnitude higher than that the original. Our findings provide references for directed evolution of enzymes and metabolic engineering in Bacillus subtilis.

17.
Electron. j. biotechnol ; 19(6): 21-25, Nov. 2016. ilus
Article in English | LILACS | ID: biblio-840308

ABSTRACT

Background: Xylitol is a five carbons polyol with promising medical applications. It can be obtained from chemical D-xylose reduction or by microbial fermentation of Sugarcane Bagasse Hemicellulosic Hydrolysate. For this last process, some microbial inhibitors, as furfural, constitute severe bottleneck. In this case, the use of strains able to produce xylitol simultaneously to furfural neutralization is an interesting alternative. A wild-type strain of Geotrichum sp. was detected with this ability, and its performance in xylitol production and furfural consumption was evaluated. Furthermore, were analyzed its degradation products. Results: Geotrichum sp. produced xylitol from D-xylose fermentation with a yield of 0.44 g-g-1. Furfural was fully consumed in fermentation assay and when provided in the medium until concentration of 6 g-L-1. The furfural degradation product is not an identified molecule, presenting a molecular weight of 161 g-mol-1, an uncommon feature for the microbial metabolism of this product. Conclusion: This strain presents most remarkable potential in performing furfural consumption simultaneous to xylitol production. Subsequent efforts must be employed to establish bioprocess to simultaneous detoxification and xylitol production by Geotrichum sp.


Subject(s)
Furaldehyde/metabolism , Geotrichum/metabolism , Polysaccharides/metabolism , Xylitol/biosynthesis , Xylose/metabolism , Fermentation
18.
Braz. arch. biol. technol ; 59: e16150475, 2016. tab, graf
Article in English | LILACS | ID: biblio-951344

ABSTRACT

ABSTRACT In Brazil, ethanol is obtained by fermentat of sugar cane juice using Saccharomyces cerevisiae. The cane juice extraction generates the bagasse that has been used for obtaining generation biofuel. However, the sugarcane bagasse has 30% pentose that cannot be fermented to ethanol by S. cerevisiae. Thus the aim of this study was to isolate a yeast able to ferment xylose to ethanol. Samples of cane juice and flowers were used for the isolation of 165 strains that were then screened for ethanol production using plate testing. Among them, the ethanol positive strains Wickerhamomyces anomalus, Schizosaccharomyces pombe and Starmerella meliponinorum were selected for a xylose fermentation assay, using a semi-synthetic and bagasse hydrolysate as must. S. meliponinorum and S. pombe produced 0.63 and 2.7 gL-1 of ethanol, respectively, from xylose in a semisynthetic medium. In the medium consisting of bagasse hydrolysate must, 0.67 and 1.1 gL-1 of ethanol were obtained from S. meliponinorum and S. pombe, respectively. All the yeasts produced xylitol from xylose in the semisynthetic medium and S. meliponinorum was that which produced the highest quantity (14.5 g L-1).

19.
China Journal of Chinese Materia Medica ; (24): 2576-2580, 2016.
Article in Chinese | WPRIM | ID: wpr-275202

ABSTRACT

To observe the effects of Atractylodis Macrocephale Rhizoma processed by different methods (sulfur-fumigation, different temperatures baking and microwave sterilization) on salivary amylase and D-xylose excretion rate in spleen deficiency rats. The rats were divided into blank control group, rhubarb-induced spleen deficiency model control group, and Atractylodis Macrocephale Rhizoma experimental groups processed with different methods. Amylase colorimetric method was used to determine the activities of salivary amylase and D-xylose excretion rate was measured with O-benzylamine method. Then the correlation of salivary amylase activity and D-xylose excretion rate in urinary was analyzed. As compared with blank control group, Atractylodis Macrocephale Rhizoma baked at 100,110 ℃ can increase the unit content of rat salivary amylase and D-xylose excretion rate, with a significant difference (P<0.05). As compared with the model group, Atractylodis Macrocephale Rhizoma baked at 70 ℃ and Atractylodis Macrocephale Rhizoma with microwave treatment had stronger effects than the others, with statistically significant differences (P<0.01). Atractylodis Macrocephale Rhizoma could improve D-xylose absorption function and salivary amylase activity in spleen deficiency rats. In addition, D-xylose excretion rate in urine was positively correlated with salivary amylase activity. Atractylodis Macrocephale Rhizoma processed with different temperatures baking and microwave sterilization had little impact on salivary amylase activity and D-xylose excretion rate in urine of spleen deficiency rats, while sulfur fumigation had great effects on the above two indexes.

20.
Nutrition Research and Practice ; : 11-18, 2016.
Article in English | WPRIM | ID: wpr-174614

ABSTRACT

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. D-Xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of D-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with D-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with D-xylose. These groups were maintained for two weeks. The effects of D-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic beta-cells were analyzed. RESULTS: In vivo, D-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. D-Xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of D-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with D-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, D-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, D-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by beta-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.


Subject(s)
Animals , Rats , Blood Glucose , Complement System Proteins , Diet , Fasting , Gluconeogenesis , Glucose Tolerance Test , Glucose , Hepatocytes , Hyperglycemia , Insulin , Insulin Resistance , Liver , Models, Animal , Muscle Cells , Pancreas , Phosphoenolpyruvate Carboxylase , Phosphoenolpyruvate , Rats, Wistar , Regeneration , Sucrase , Sucrose , Xylose
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