RESUMO
The bioresource utilization of herbal biomass residues (HBRs) has been receiving more attention. Herein, three different HBRs from Isatidis Radix (IR) and Sophorae Flavescentis Radix (SFR) and Ginseng Radix (GR) were subjected to batch and fed-batch enzymatic hydrolysis to produce high-concentration glucose. Compositional analysis showed the three HBRs had substantial starch content (26.36-63.29%) and relatively low cellulose contents (7.85-21.02%). Due to their high starch content, the combined action of cellulolytic and amylolytic enzymes resulted in greater release of glucose from the raw HBRs compared to using the individual enzyme alone. Batch enzymatic hydrolysis of 10% (w/v) raw HBRs with low loadings of cellulase (≤ 10 FPU/g substrate) and amylolytic enzymes (≤ 5.0 mg/g substrate) led to a high glucan conversion of ≥ 70%. The addition of PEG 6000 and Tween 20 did not contribute to glucose production. Furthermore, to achieve higher glucose concentrations, fed-batch enzymatic hydrolysis was conducted using a total solid loading of 30% (w/v). After 48-h of hydrolysis, glucose concentrations of 125 g/L and 92 g/L were obtained for IR and SFR residues, respectively. GR residue yielded an 83 g/L glucose concentration after 96 h of digestion. The high glucose concentrations produced from these raw HBRs indicate their potential as ideal substrate for a profitable biorefinery. Notably, the obvious advantage of using these HBRs is the elimination of the pretreatment step, which is typically required for agricultural and woody biomass in similar studies.
Assuntos
Celulase , Glucose , Glucose/química , Amido , Biomassa , Celulose , Glucanos , Hidrólise , Celulase/químicaRESUMO
Pectic substances cause haziness and high viscosity of fruit juices. Pectinase enzymes are biological compounds that degrade pectic compounds. Nontoxicity and ecofriendly nature make pectinases excellent biocatalysts for juice clarification. However, the poor stability and nonreusability of pectinases trim down the effectiveness of the operation. The immobilization techniques have gained the attention of researchers as it augments the properties of the enzymes. Literature has reported the stability improvement of enzymes like lipase, laccase, hydrogen peroxidase, and cellulase upon immobilization on the membrane. However, only a few research articles divulge pectinase immobilization using a membrane. The catalysis-separation synergy of membrane-reactor has put indelible imprints in industrial applications. Immobilization of pectinase on the membrane can enhance its performance in juice processing. This review delineates the importance of physicochemical and kinematic properties of pectinases relating to the juice processing parameters. It also includes the influence of metal-ion cofactors on enzymes' activity. Considering the support and catalytic-separation facets of the membrane, the prediction of the membrane as support for pectinase immobilization has also been carried out.
Assuntos
Celulase , Poligalacturonase , Celulase/química , Enzimas Imobilizadas/metabolismo , Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais , Pectinas , Poligalacturonase/químicaRESUMO
Biomass pre-treatment is a key step in achieving the economic competitiveness of biomass conversion. In the present work, an imidazole pre-treatment process was performed and evaluated using wheat straw and eucalyptus residues as model feedstocks for agriculture and forest-origin biomasses, respectively. Results showed that imidazole is an efficient pre-treatment agent; however, better results were obtained for wheat straw due to the recalcitrant behavior of eucalyptus residues. The temperature had a stronger effect than time on wheat straw pre-treatment but at 160 °C and 4 h, similar results were obtained for cellulose and hemicellulose content from both biomasses (ca. 54% and 24%, respectively). Lignin content in the pre-treated solid was higher for eucalyptus residues (16% vs. 4%), as expected. Enzymatic hydrolysis, applied to both biomasses after different pre-treatments, revealed that results improved with increasing temperature/time for wheat straw. However, these conditions had no influence on the results for eucalyptus residues, with very low glucan to glucose enzymatic hydrolysis yield (93% for wheat straw vs. 40% for eucalyptus residues). Imidazole can therefore be considered as a suitable solvent for herbaceous biomass pre-treatment.
Assuntos
Biomassa , Celulase/química , Celulose/química , Eucalyptus/química , Imidazóis/química , Triticum/químicaRESUMO
Three non-conventional extraction techniques (enzyme-assisted with cellulase, citric acid ultrasound-assisted and enzyme-ultrasound-assisted treatment) and conventional citric acid extraction were applied to obtain pectin from raspberry, blueberry, strawberry and redcurrant, and were compared in terms of extraction yields and physicochemical properties of the extracted pectins. Except for pectin from raspberry, conventional citric acid extraction led to the highest extraction yield (~8%) and, for the same berries, the lowest pectin recovery was found for the extraction with cellulase (~4%). Regarding the structural characteristics of pectins, enzymatically extracted pectins from redcurrant and strawberry exhibited the highest levels of galacturonic acid (≥73%) whereas, in general, this monosaccharide was found from 51 to 69% in the rest of samples. Although, ultrasound-assisted extraction did not improve pectin yield, it minimized the levels of "non-pectic" components leading to the obtainment of purer pectin. The different monomeric composition and the wide range of molecular weight of the obtained pectins pointed out their usefulness in different potential food applications (e.g., thickening, gelling ingredients) and biological activities. This has been evidenced by the differences found in their physicochemical and techno-functional characteristics. Finally, it can be considered that the berries here studied are efficient sources of pectin.
Assuntos
Fracionamento Químico , Frutas/química , Pectinas/isolamento & purificação , Rosales/química , Celulase/química , Ácido Cítrico/química , Fragaria/química , Peso Molecular , Ribes/química , Rubus/química , UltrassomRESUMO
In this paper, ultrasonic cellulase extraction (UCE) was applied to extract polyphenols from passion fruit. The extraction conditions for total phenol content (TPC) and antioxidant activity were optimized using response surface methodology (RSM) coupled with a Box-Behnken design (BBD). The results showed that the liquid-to-solid ratio (X2) was the most significant single factor and had a positive effect on all responses. The ANOVA analysis indicated quadratic models fitted well as TPC with R2 = 0.903, DPPH scavenging activity with R2 = 0.979, and ABTS scavenging activity with R2 = 0.981. The optimal extraction parameters of passion fruit were as follows: pH value of 5 at 30 °C for extraction temperature, 50:1 (w/v) liquid-to-solid ratio with extraction time for 47 min, the experimental values were found matched with those predicted. Infrared spectroscopy suggested that the extract contained the structure of polyphenols. Furthermore, three main polyphenols were identified and quantified by HPLC. The results showed the content of phenolic compounds and antioxidant activity of the optimized UCE were 1.5~2 times higher than that determined by the single extraction method and the Soxhlet extraction method, which indicates UCE is a competitive and effective extraction technique for natural passion fruit polyphenols.
Assuntos
Antioxidantes/isolamento & purificação , Passiflora/química , Extratos Vegetais/química , Polifenóis/isolamento & purificação , Antioxidantes/química , Celulase/química , Cromatografia Líquida de Alta Pressão , Polifenóis/química , UltrassomRESUMO
Endophytes may depend on degrading the plant cell wall with cellulases for their survival. Therefore, cellulase produced by endophytes may be useful in releasing the active ingredient of medicinal plants. Scutellaria baicalensis Georgi is a traditional Chinese medicinal plant widely used in China and baicalin is one of its main active ingredients. In this study, fresh S. baicalensis Georgi was used to isolate endophytes, Congo red staining was used to screen cellulase-producing strains, and HPLC was used to determine the content of baicalin in S. baicalensis Georgi. As a result, a highly active strain of endophyte capable of the extraction of high levels of baicalin was obtained. The strain was named HG-5 and identified as Bacillus sp. Scanning electron microscopy analysis confirmed that the enzyme better promotes the dissolution of plant active ingredients. After optimizing the enzyme production and extraction processes, we found that when compared with the traditional extraction method, the baicalin yield was increased 79.31% after extraction with the HG-5 enzyme. The current study provides a novel approach and method for the use of endophyte cellulase to improve the extraction of compounds from medicinal plants.
Assuntos
Flavonoides/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Scutellaria baicalensis/metabolismo , Bacillus/metabolismo , Parede Celular/metabolismo , Celulase/química , Cromatografia Líquida de Alta Pressão , Endófitos/metabolismo , Fermentação , Microscopia Eletrônica de Varredura , Filogenia , Extratos Vegetais/química , Análise de RegressãoRESUMO
The medicinal plant Artemisia annua L. is well known for its antimalarial compound artemisinin and the antioxidant capacity of its active ingredients. However, low bioavailability of Artemisia annua L. limits its therapeutic potential, fermentation of Artemisia annua L. can improve its bioavailability. This study was aimed to investigate the effects of dietary supplementation of enzymatically-treated Artemisia annua L. (EA) on reproductive performance, antioxidant status, milk composition of heat-stressed sows and intestinal barrier integrity of their preweaning offspring. 135 multiparous sows of average parity 4.65 (Landrace × large white) at day 85 of pregnancy were randomly distributed into 3 treatments. Sows in the control group were housed at control rooms (temperature: 27.12 ± 0.18 °C, temperature-humidity index (THI): 70.90 ± 0.80) and fed the basal diet. Sows in the HS, HS + EA groups were fed the basal diet supplemented with 0 or 1.0 g/kg EA respectively, and reared at heat stress rooms (temperature: 30.11 ± 0.16 °C, THI: 72.70 ± 0.60). Heat stress increased the malondialdehyde (MDA) content, reduced the activities of total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) of sows and piglets, and seriously compromised the antioxidant capacity of the sows and the intestinal integrity of their offspring. However, dietary supplementation of 1.0 g/kg EA reduced the MDA content, increased the activities of T-SOD and T-AOC in serum, colostrum, and milk of heat-stressed sows, and increased colostrum yield and 14-d milk fat content. EA supplementation also increased piglet weaning weight and the activities of T-SOD and T-AOC in serum. In addition, the abundances of intestinal tight junction proteins claudin-1 and occludin were up-regulated in piglets in EA-supplemented group. In conclusion, dietary EA supplementation at 1.0 g/kg can alleviate the oxidative stress in heat-stressed sows, improve the antioxidant capacity in both sows and their offspring, and promote the intestinal barrier integrity in their offspring. EA may be a potent dietary supplement that ameliorates oxidative stress in livestock production by improving the antioxidant capacity.
Assuntos
Artemisia annua , Suplementos Nutricionais , Temperatura Alta/efeitos adversos , Estresse Oxidativo , Reprodução , Ração Animal , Animais , Artemisia annua/química , Celulase/química , Dieta/veterinária , Feminino , Glutationa/sangue , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/genética , Transtornos de Estresse por Calor/veterinária , Leite/química , Oxirredutases/sangue , Poligalacturonase/química , Gravidez , Suínos/sangue , Suínos/genética , Doenças dos Suínos/sangue , Doenças dos Suínos/genética , Proteínas de Junções Íntimas/genéticaRESUMO
Organosolv pretreatment with two ethanol concentrations (25% and 50%, v/v) was performed to improve enzymatic saccharification of poplar sawdust. It was found that lower ethanol concentration (25%, v/v) pretreatment resulted in a higher enzymatic digestibility of poplar (38.1%) due to its higher xylan removal and similar lignin removal ratios, compared to that pretreated with 50% (v/v) ethanol pretreatment (27.5%). However, the residual lignin still exhibited a strong inhibition on enzymatic hydrolysis of organosolv-pretreated poplar (OP). Bio-surfactant preparations including tea saponin (TS), TS crude extract, and tea seed waste were applied in enzymatic hydrolysis of OP, due to their potential ability of reducing enzyme non-productive binding on lignin. Their optimal loadings in enzymatic hydrolysis of OP were optimized, which indicated that adding 0.075 g/g glucan of TS improved the 72-h glucose yield of OP by 48.3%. Moreover, adding TS crude extract and tea seed waste exhibited the better performance than TS for improving enzymatic hydrolysis of OP. It was verified that the presence of protein in TS crude extract and tea seed waste accounted for the higher improvement. More importantly, the directly application of tea seed waste in enzymatic hydrolysis could achieve the similar improvement on enzymatic hydrolysis of OP, where chemosynthetic surfactant (PEG6000) was added. The residual enzyme activities in supernatant of enzymatic hydrolysis were also determined to reveal the changes on enzyme adsorption after adding surfactants. Generally, tea seed waste could be directly applied as an alternative to chemosynthetic surfactants to promote enzymatic hydrolysis of lignocelluloses.
Assuntos
Biotecnologia/métodos , Celulase/química , Glucose/química , Lignina/química , Saponinas/química , Solventes/química , Chá , Adsorção , Biomassa , Celulose/metabolismo , Etanol/metabolismo , Hidrólise , Resíduos Industriais , Tensoativos/química , Árvores , Água/química , MadeiraRESUMO
Oral drug delivery systems for time-controlled release, intended for chronotherapy or colon targeting, are often in the form of coated dosage forms provided with swellable/soluble hydrophilic polymer coatings. These are responsible for programmable lag phases prior to release, due to their progressive hydration in the biological fluids. When based on high-viscosity polymers and/or manufactured by press-coating, the performance of functional hydroxypropyl methylcellulose (HPMC) layers was not fully satisfactory. Particularly, it encompassed an initial phase of slow release because of outward diffusion of the drug through a persistent gel barrier surrounding the core. To promote erosion of such a barrier, the use of a cellulolytic product (Sternzym® C13030) was here explored. For this purpose, the mass loss behavior of tableted matrices based on various HPMC grades, containing increasing percentages of Sternzym® C13030, was preliminarily studied, highlighting a clear and concentration-dependent effect of the enzyme especially with high-viscosity polymers. Subsequently, Sternzym® C13030-containing systems, wherein the cellulolytic product was either incorporated into a high-viscosity HPMC coating or formed a separate underlying layer, were manufactured. Evaluated for release, such systems gave rise to more reproducible profiles, with shortened lag phases and reduced diffusional release, as compared to the reference formulation devoid of enzyme.
Assuntos
Acetaminofen/administração & dosagem , Celulase/química , Sistemas de Liberação de Medicamentos/métodos , Derivados da Hipromelose/química , Comprimidos/química , Administração Oral , Química Farmacêutica , Preparações de Ação Retardada , Tamanho da Partícula , Solubilidade , Tecnologia FarmacêuticaRESUMO
Spent coffee grounds (SCG) are a promising raw material for galactomannan (GalM) production based upon its enrichment in galactomannan polysaccharides. In this work, SCG was pretreated by autohydrolysis for maximumly improving GalM extractability by endo-mannanase. The GalM in the prehydolyzate (GalM-PH) and enzymatic hydrolyzate (GalM-EH) were obtained by ethanol precipitation and characterized. Under the optimized autohydrolysis conditions, 50.1% of GalM in pretreated SCG was converted into free GalM in enzymatic hydrolyzate. Compositional analysis results revealed that GalM-PH was comprised of 81.7% galactomannan, higher than that of GalM-EH (76.4%). The molecular weight of GalM-PH and GalM-EH were 44.5 kDa and 28.0 kDa, respectively. Antioxidant assays indicated that both GalM-EH and GalM-PH could scavenge 2,2-diphenyl-1-picryl-hydrazyl radicals and hydroxyl radicals. Immunological and prebiotics analysis showed all GalM preparations exhibited pronounced activities for proliferating the probiotics and proliferating the Macrophages cell for NO production, in which the GalM-EH outperformed the GalM-PH. These results imply that the GalM extracted from SCG are the bioactive substances that can be used as antioxidant, prebiotics, and immunostimulants.
Assuntos
Antioxidantes/química , Café/química , Mananas/química , Polissacarídeos/química , Antioxidantes/isolamento & purificação , Celulase/química , Etanol/química , Galactose/análogos & derivados , Humanos , Hidrólise , Mananas/isolamento & purificação , Polissacarídeos/isolamento & purificação , Resíduos , beta-Manosidase/químicaRESUMO
Anthocyanins in wine principally depend on grape skin extractable anthocyanin content, that is, the amount of anthocyanins present in grape skin that are released to wine during the maceration stage. This amount of extractable anthocyanins is closely linked to the cell wall degradation of skin cells. Indeed, among other methodologies, the maceration in presence of different enzymes can be used to increase cell wall degradation, and therefore, the amount of anthocyanins extracted from grape skins to wine. Vitis vinifera L. cv. Tempranillo and Syrah red grapes have been identified as samples with low anthocyanin extraction potential by near infrared hyperspectral imaging. Grape skins have been macerated in the presence of cellulase, glucosidase, and pectinase. Then, color of the supernatants and phenolic compounds extracted from grape skins (total phenols, total flavanols, and total and individual anthocyanins) has been determined. Cellulase and glucosidase have shown a positive effect in the extraction of phenolic compounds from these grapes. Macerations carried out in the presence of cellulase have produced supernatants with a more intense color (lower lightness and higher chroma values), and a higher extraction of flavanols and anthocyanins than the respective control essays. However, pectinase treatments have produced the opposite effect, which could be partially explained by an eventual interaction between the cell wall polysaccharides liberated by pectinase and the phenolic compounds extracted. Synergy effects do not appear between cellulase and glucosidase. Moreover, the negative effect of the addition of pectinase might be due to the interactions between the cell wall material liberated by pectinase and the phenolic compounds extracted. PRACTICAL APPLICATION: In the present study, grape samples with a low anthocyanin extraction potential have been identified, and these samples have been macerated in the presence of different enzymes. The applied enzymes were three of the most common enzymes that are applied in the wine industry. Individual enzymes and mixtures have been applied to Syrah and Tempranillo grape skin samples and the results have been compared to control macerations. Knowledge in this topic will help the production of quality wines.
Assuntos
Antocianinas/análise , Antocianinas/isolamento & purificação , Fenóis/análise , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Vitis/química , Biocatálise , Celulase/química , Cor , Frutas/química , Glucosidases/química , Fenóis/química , Poligalacturonase/química , Vinho/análiseRESUMO
Enzyme-assisted aqueous extraction of rice germ oil (RGO) was performed in this study. The physicochemical properties, fatty acid composition, bioactive substances and antioxidant activity of RGO were analyzed. An enzyme composed of alcalase and cellulase (1:1, w/w) was found to be the most effective in the extraction yield of oil. The optimal oil yield of 22.27% was achieved under the conditions of an enzyme concentration of 2% (w/w), incubation time of 5 h, incubation temperature of 50°C, water to seed ratio of 5:1, and pH 6.0. The predominant fatty acids of RGO were oleic acid (39.60%), linoleic acid (34.20%) and palmitic acid (20.10%). The total saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) composition of RGO were 22.50%, 39.60% and 36.00%, respectively. RGO yielded a high content of γ-oryzanol (530 mg/100 g oil), tocotrienol (62.96 mg/100 g oil), tocopherol (23.24 mg/100 g oil) and a significant amount of phytosterol (372.14 mg/100 g oil). It exhibited notable antioxidant activities with IC50 values of 32.37 and 41.13 mg/mL, according to the DPPH radical scavenging assay and ß-carotene/linoleic acid bleaching test, respectively.
Assuntos
Sequestradores de Radicais Livres/química , Oryza/química , Óleos de Plantas/química , Sementes/química , Celulase/química , Ácidos Graxos/análise , Sequestradores de Radicais Livres/análise , Sequestradores de Radicais Livres/isolamento & purificação , Fitosteróis/análise , Óleos de Plantas/análise , Óleos de Plantas/isolamento & purificação , Extração em Fase Sólida/métodos , Subtilisinas/química , Tocoferóis/análiseRESUMO
In this work, cellulose was extracted from potato pulp, a low-efficiently utilized by-product from potato starch industry, by a combined alkali and sodium sulfite treatment. Its physicochemical properties were characterized and compared with cellulose from corn stalk. The yield and purity of cellulose from potato pulp were determined to be 24.74% and 81.34% respectively. Cellulose from potato pulp had more loosened and porous structure, lower crystallinity index and larger specific surface area (SSA) compared with cellulose from corn stalk. It also provided the highest accessibility to cellulase (5.7â¯mg protein/g glucan) and had the highest enzymatic digestibility (with glucose yield of 88.46%). Maximum adsorption capacity (Wmax) and equilibrium constant (K) were obtained by fitting the adsorption data with the Langmuir adsorption isotherm, suggesting that cellulose from potato pulp had the highest cellulase adsorption efficiency. The data further indicated that the presence of non-cellulosic components, especially for pectin, appeared to have a considerable effect on the hydrolysis by cellulase due to non-productive adsorption. State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.
Assuntos
Celulase/química , Celulose/química , Solanum tuberosum/química , Hidrólise , Cinética , Peso Molecular , Solanum tuberosum/enzimologia , Análise EspectralRESUMO
Ginseng stems and leaves (GSAL) are abundant in ginsenosides compounds. For efficient utilization of GSAL and the enhancement of total ginsenosides (TG) compound yields in GSAL, TG from GSAL were extracted, using dynamic-microwave assisted extraction coupled with enzymatic hydrolysis (DMAE-EH) method. The extraction process has been simulated and its main influencing factors such as ethanol concentration, microwave temperature, microwave time and pump flow rate have been optimized by response surface methodology coupled with a Box-Behnken design(BBD). The experimental results indicated that optimal extraction conditions of TG from GSAL were as follows: ethanol concentration of 75%, microwave temperature of 60°C, microwave time of 20 min and pump flow rate of 38 r/min. After experimental verification, the experimental yields of TG was 60.62 ± 0.85 mg g-1, which were well agreement with the predicted by the model. In general, the present results demonstrated that DMAE-EH method was successfully used to extract total ginsenosides in GSAL.
Assuntos
Ginsenosídeos/isolamento & purificação , Panax/química , Extração em Fase Sólida/métodos , Celulase/química , Etanol/química , Ginsenosídeos/química , Hidrólise , Micro-Ondas , Folhas de Planta/química , Caules de Planta/química , Análise de Regressão , Solventes/química , TemperaturaRESUMO
The present work investigated the antioxidative, anti-inflammatory and pulmonary protective effects of enzymatic- and acid- hydrolysed mycelia polysaccharides (En-MPS and Ac-MPS) from Oudemansiella radicata on LPS-induced acute lung injury (ALI) mice. The results demonstrated that both En-MPS and Ac-MPS showed potential pulmonary protective effects by decreasing serum levels of hs-CRP and C3, increasing pulmonary enzyme values of SOD, GSH-Px, CAT and the level of T-AOC; reducing the activity of MPO; and down-regulating the contents of MDA and LPO. In addition, the levels of TNF-É, IL-1ß, and IL-6 in BALF of mice treated with En-MPS at a dosage of 400 mg/kg/d were significantly lower than those in the ALI mice. The in vitro antioxidant effects also showed that the En-MPS was more effective than Ac-MPS. Furthermore, the physical properties of polysaccharides were also investigated by GC, HPGPC, FT-IR and NMR. These results indicated that both En-MPS and Ac-MPS possessed potent antioxidant and anti-inflammatory activities, which could be used as an ingestible drug in preventing lung injury.
Assuntos
Agaricales/química , Anti-Inflamatórios não Esteroides/uso terapêutico , Antioxidantes/uso terapêutico , Lesão Pulmonar/tratamento farmacológico , Micélio/química , Polissacarídeos/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/toxicidade , Antioxidantes/química , Antioxidantes/toxicidade , Celulase/química , Glucuronidase/química , Hidrólise , Interleucina-1alfa/metabolismo , Interleucina-6/metabolismo , Pulmão/patologia , Lesão Pulmonar/patologia , Masculino , Camundongos , Complexos Multienzimáticos/química , Poligalacturonase/química , Polissacarídeos/química , Polissacarídeos/toxicidade , Substâncias Protetoras/química , Substâncias Protetoras/uso terapêutico , Substâncias Protetoras/toxicidade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We investigated the cellulase-assisted extraction and anti-ultraviolet activity of water-soluble polysaccharides from the root of Flammulina velutipes on Caenorhabditis elegans. A Box-Behnken design experiment with three factors and three levels, including enzymolysis temperature, microwave time, and microwave power, was designed on the basis of the results of single-factor experiments. For improving the polysaccharide yield of F. velutipes root, the following optimal extraction conditions were used: 52.67°C enzymolysis temperature, 80s microwave time, and 144 W microwave power. Under optimal conditions, the actual measured value of the yield was 2.01% (w/w) and the predicted value was 2.06% (w/w). One fraction (FRP-2) was isolated and purified, and its characteristics were analyzed. The average mean molecular weight of FRP-2 was measured to be 2.60×105 Da, and its monosaccharide composition is mainly glucose. The sugar units are present both in the α-configuration and ß-configuration. Moreover, FRP-2 exhibited certain anti-ultraviolet activity to C. elegans when the polysaccharide concentration ranged between 0.05mg/mL and 0.20mg/mL.
Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/efeitos da radiação , Celulase/química , Flammulina , Extratos Vegetais/farmacologia , Raízes de Plantas , Polissacarídeos/farmacologia , Protetores contra Radiação/farmacologia , Raios Ultravioleta , Animais , Configuração de Carboidratos , Flammulina/química , Hidrólise , Micro-Ondas , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Protetores contra Radiação/química , Protetores contra Radiação/isolamento & purificação , Relação Estrutura-Atividade , Temperatura , Fatores de TempoRESUMO
The conversion of cellulosic biomass into biofuels requires degradation of the biomass into fermentable sugars. The most efficient natural cellulase system for carrying out this conversion is an extracellular multi-enzymatic complex named the cellulosome. In addition to temperature and pH stability, mechanical stability is important for functioning of cellulosome domains, and experimental techniques such as Single Molecule Force Spectroscopy (SMFS) have been used to measure the mechanical strength of several cellulosomal proteins. Molecular dynamics computer simulations provide complementary atomic-resolution quantitative maps of domain mechanical stability for identification of experimental leads for protein stabilization. In this study, we used multi-scale steered molecular dynamics computer simulations, benchmarked against new SMFS measurements, to measure the intermolecular contacts that confer high mechanical stability to a family 3 Carbohydrate Binding Module protein (CBM3) derived from the archetypal Clostridium thermocellum cellulosome. Our data predicts that electrostatic interactions in the calcium binding pocket modulate the mechanostability of the cellulose-binding module, which provides an additional design rule for the rational re-engineering of designer cellulosomes for biotechnology. Our data offers new molecular insights into the origins of mechanostability in cellulose binding domains and gives leads for synthesis of more robust cellulose-binding protein modules. On the other hand, simulations predict that insertion of a flexible strand can promote alternative unfolding pathways and dramatically reduce the mechanostability of the carbohydrate binding module, which gives routes to rational design of tailormade fingerprint complexes for force spectroscopy experiments.
Assuntos
Proteínas de Bactérias/química , Cálcio/química , Celulase/química , Simulação de Dinâmica Molecular , Complexos Multienzimáticos/química , Fenômenos Biomecânicos , Cátions Bivalentes , Ligação Proteica , Conformação Proteica , Zinco/químicaRESUMO
A novel KG51 gene was isolated from a metagenomic library of Korean black goat rumen and its recombinant protein was characterized as a bifunctional enzyme (cellulase/hemicellulase). In silico sequence and domain analyses revealed that the KG51 gene encodes a novel carbohydrate-active enzyme that possesses a salad-bowl-like shaped glycosyl hydrolase family 5 (GH5) catalytic domain but, at best, 41% sequence identity with other homologous GH5 proteins. Enzymatic profiles (optimum pH values and temperatures, as well as pH and thermal stabilities) of the recombinant KG51 bifunctional enzyme were also determined. On the basis of the substrate specificity data, the KG51 enzyme exhibited relatively strong cellulase (endo-ß-1,4-glucanase [EC 3.2.1.4]) and hemicellulase (mannan endo-ß-1,4-mannosidase [EC 3.2.1.78] and endo-ß-1,4-xylanase [EC 3.2.1.8]) activities, but no exo-ß-1,4-glucanase (EC 3.2.1.74), exo-ß-1,4-glucan cellobiohydrolase (EC 3.2.1.91), and exo-1,4-ß-xylosidase (EC 3.2.1.37) activities. Finally, the potential industrial applicability of the KG51 enzyme was tested in the preparation of prebiotic konjac glucomannan hydrolysates.
Assuntos
Celulase/química , Glicosídeo Hidrolases/química , Cabras/genética , Rúmen/enzimologia , Sequência de Aminoácidos , Amorphophallus/química , Animais , Celulase/genética , Celulase/metabolismo , Estabilidade Enzimática , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Mananas/química , Metagenômica , Dados de Sequência Molecular , Extratos Vegetais/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rúmen/química , Alinhamento de Sequência , Especificidade por Substrato , TemperaturaRESUMO
The α- and γ-mangostins from Garcinia mangostana pericarps (GMP) exhibit antioxidant, anti-bacterial, anti-inflammatory and anti-tumor properties. The extraction yields α- and γ-mangostins are often limited by the presence of the GMP cell walls. Therefore, the extraction and recovery of mangostins from GMP with an Aspergillus niger cellulase-assisted aqueous micellar biphasic system (CA-AMBS) was developed for enhanced yield of mangostins. Effects of the concentration of cellulase, the incubation time and the temperature of the system on the recovery of mangostins were investigated. The optimum condition for the recovery of α- and γ-mangostins was obtained with the addition of 0.5% (w/w) cellulase incubated at 40°C for 2 h. High log partition coefficients of α-mangostins (log Kα 4.79 ± 0.02) and γ-mangostins (log Kγ 4.02 ± 0.02) were achieved. High yields of α-mangostins (73.4%) and γ-mangostins (14.0%) were obtained from the micelle-rich bottom phase with final concentrations of 3.67 mg/mL and 0.70 mg/mL, respectively. The back-extraction of mangostins was performed with the addition of 30% (w/w) of isopropanol and 0.05 M of KCl at pH 9 to the bottom phase of the CA-AMBS. The yields of the α- and γ-mangostins from GMP were considerably enhanced with the CA-AMBS and the direct recovery of mangostins was demonstrated without additional downstream processing steps.
Assuntos
Celulase/química , Garcinia mangostana/química , Extratos Vegetais/química , Tensoativos/química , Xantonas/química , Antioxidantes/análise , Antioxidantes/isolamento & purificação , Biocatálise , Frutas/química , Micelas , Extratos Vegetais/isolamento & purificação , Xantonas/isolamento & purificaçãoRESUMO
In this study, enzyme-assisted extraction was used to isolate functional polysaccharides from Korean ginseng (Panax ginseng Meyer) and the physicochemical and biological properties of the extracted polysaccharides were investigated, comparing with those from traditional hot-water extraction (FGWP). In macrophages, their effects on cytokines production could be ordered as FGEP-CAâ¯≥â¯FGEP-Aâ¯>â¯FGEP-Câ¯>â¯FGWP, suggesting that FGEP-CA (combined cellulase- and α-amylase-extracted polysaccharide) is a potent immunostimulator. In addition, enzymatic digestion led to differences in the monosaccharide profile of the extract. FGWP mainly consisted of rhamnose, arabinose, galactose, galacturonic acid, and glucose in molar percentages of 1.8:10.1:9.2:17.8:60.6, whereas FGEP-CA was 3.2:11.4:16.5:22.3:45.8, respectively, suggesting that enzyme-assisted extraction of ginseng polysaccharides produces a higher proportion of pectin polysaccharides. The HPLC profile of FGEP-CA also showed lower and more heterogeneous molecular weights than FGWP did. In cyclophosphamide-induced immunosuppressed mice, FGEP-CA administration ameliorated decreased spleen and thymus indices (200â¯mg/kg), lymphocyte proliferation, natural killer cell activity, leukocyte counts, and the serum cytokines, interleukin-2, interleukin-6, and interferon-γ (100 and 200â¯mg/kg). These results suggest that enzyme-assisted extraction using cellulase and α-amylase is an effective method for the preparation of functional polysaccharides from fresh Korean ginseng, and FGEP-CA could be utilized as a potential immune-stimulatory agent.