Study on the Optimum Condition for Immobilization and Properties of Laccase on Coordinated Chitosan-Cu2+

2013 ◽  
Vol 864-867 ◽  
pp. 1262-1265 ◽  
Author(s):  
Bo Yang ◽  
Xu Ming Wang
Keyword(s):  
Optimum Condition ◽  
Heat Resistance ◽  
High Activity ◽  
Storage Stability ◽  
Optimal Conditions ◽  
Immobilized Laccase ◽  
Complex Time ◽  
Optimum Ph ◽  
Polymeric Coordination ◽  
Optimum Ph And Temperature

Coordinated chitosan-Cu2+ as a carrier, the laccase was immobilized on it by polymeric coordination method. In this study, the optimal conditions for immobilization and properties of laccase were investigated. The optimal conditions for immobilization were: CuSO4 (0.05 mol/L), complex time (7 h), laccase concentration (250 U/mL), immobilization time (8 h). Under this condition, the activity of immobilized laccase can reach 820 U/g. In comparison with the free laccase, the optimum pH and temperature of immobilized laccase have a little change, while the heat resistance and pH stability were improved. After the immobilized laccase was stored in the refrigerator at 4 °C for 25 days, the activity of it remained 69.5 % of the original, it illustrates the immobilized laccase has a good storage stability. The laccase immobilized with chitosan-Cu2+ has high activity and has potential to use in industry as a biocatalyst.

scholarly journals Investigation of Optimal Conditions for Production, Characterization, and Immobilization of Fructosyltransferase and β-Fructofuranosidase by Filamentous Fungi

2020 ◽  
Vol 11 (4) ◽  
pp. 11187-11201
Keyword(s):  
Thermal Stability ◽  
Aspergillus Niger ◽  
Kinetic Parameters ◽  
Filamentous Fungi ◽  
Storage Stability ◽  
Optimal Conditions ◽  
Extracellular Production ◽  
Optimum Ph ◽  
Optimum Ph And Temperature ◽  
Penicillium Brasilianum

This work's objective was the extracellular production, partial characterization, and immobilization of the enzymes fructosyltransferase (Ftase) and β-fructofuranosidadase (Ffase) by filamentous fungi. Aspergillus niger ATCC 9642 and Penicillium brasilianum were evaluated for the production of fructosyltransferase (Ftase) and β-fructofuranosidadase (FASE) enzymes. The A. niger presented the highest activity of FTase (24.86 µmol/min.mL) and FFase (28.68 µmol/min.mL) in medium composed of 20% sucrose, 0.5% yeast extract, 1% NaNO3, 0.05% MgSO4.7 H2O, 0.25% KH2PO4, 0.5% NH4Cl and 0.25% NaCl inoculated using 5x107spores/mL and incubated at 25°C, pH 5.5, 150 rpm for 48 h. Presenting optimum pH and temperature of 2.39 and 60°C. Thermal stability has shown that the enzyme FFase is more thermally stable when compared to FTase. Stability against different pHs showed similar behavior for FTase and FFase; the optimum pH being between 2.0 and 3.0. FTase and FFase showed storage stability in freezing and refrigeration temperature for approximately 400 h. The kinetic parameters, Km and Vmax, for the sucrose substrate were 24.60mM and 104.16 μmol/min.mL for FTase and 3.91mM and 20.24 μmol/min.mL for FFase. The immobilization process displayed a yield of 6744.66% for FFase and 3928.90% for FTase, with enzymatic activities of 364.79 U/g and 220.34 U/g, and 4 and 3 times reuse, respectively.

Immobilization and Characterization of Tannase and its Haze-removing

2009 ◽  
Vol 15 (6) ◽  
pp. 545-552 ◽  
Author(s):  
Erzheng Su ◽  
Tao Xia ◽  
Liping Gao ◽  
Qianying Dai ◽  
Zhengzhu Zhang
Keyword(s):  
Kinetic Parameter ◽  
High Activity ◽  
Green Tea ◽  
Storage Stability ◽  
Residual Activity ◽  
Black Tea ◽  
Optimum Temperature ◽  
Oolong Tea ◽  
Optimum Ph

Tannase was effectively immobilized on alginate by the method of crosslinking-entrapment-crosslinking with a high activity recovery of 76.6%. The properties of immobilized tannase were investigated. Its optimum temperature was determined to be 35 ° C, decreasing 10 °C compared with that of free enzyme, whereas the optimum pH of 5.0 did not change. The thermal and pH stabilities of immobilized tannase increased to some degree. The kinetic parameter, Km, for immobilized tannase was estimated to be 11.6 × 10-4 mol/L. Fe2+ and Mn2+ could activate the activity of immobilized tannase. The immobilized tannase was also applied to treat the tea beverage to investigate its haze-removing effect. The content of non-estern catechins in green tea, black tea and oolong tea increased by 52.17%, 12.94% and 8.83%, respectively. The content of estern catechins in green tea, oolong tea and black tea decreased by 20.0%, 16.68% and 5.04%, respectively. The anti-sediment effect of green tea infusion treated with immobilized tannase was significantly increased. The storage stability and reusability of the immobilized tannase were improved greatly, with 72.5% activity retention after stored for 42 days and 86.9% residual activity after repeatedly used for 30 times.

scholarly journals Utilization of Crude Intracellular Chitinase Enzyme from Providencia stuartii for Glucosamine Production from Shrimp Shells

REAKTOR ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 62-67
Author(s):  
Hardoko Hardoko ◽  
Titri Siratantri Mastuti ◽  
Desy Puspasari ◽  
Yuniwaty Halim
Keyword(s):  
Optimum Condition ◽  
Substrate Concentration ◽  
Intracellular Enzyme ◽  
Fermentation Time ◽  
Shrimp Shells ◽  
Optimum Ph ◽  
Chitin Hydrolysis ◽  
Providencia Stuartii ◽  
Optimum Ph And Temperature

Chitin hydrolysis using enzyme is one of the methods to produce glucosamine in shorter time compared to using microbial cells, but the ability to produce glucosamine at enzyme’s optimum condition is influenced by substrate concentration and fermentation time. The objective of this research was to determine the optimum substrate concentration and fermentation time of shrimp shells’ chitin to produce glucosamine at the optimum pH and temperature of crude intracellular chitinase enzyme from Providencia stuartii. Method used was experimental method, started by extraction of intracellular enzyme from P. stuartii, followed by determination of optimum pH and temperature of enzyme. The optimum condition was used for experiment of shrimp shells’ chitin fermentation with treatments of chitin substrate concentration (0.5; 1.0; 1.5; 2.0%) and fermentation time (2, 4, 6 and 24 hours). Results showed that optimum enzyme activity occurred at pH of 5.0 and temperature of 40oC, which was about 6.03 U/ml. Concentration of chitin substrate and fermentation time influenced the amount of glucosamine obtained. Fermentation of shrimp shells’ chitin using crude intracellular enzyme was optimum at 1.0% substrate concentration and 6 hours fermentation time, which produced glucosamine about 1680.06±58.49 ppm. Keywords: intracellular chitinase enzyme, glucosamine, shrimp shells’ chitin, P. stuartii

scholarly journals Immobilization of alpha-amylase produced by Bacillus circulans GRS 313

2003 ◽  
Vol 46 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Gargi Dey ◽  
Singh Bhupinder ◽  
Rintu Banerjee
Keyword(s):  
Calcium Alginate ◽  
Immobilized Enzyme ◽  
Fold Increase ◽  
Alginate Beads ◽  
Hydrolysis Kinetics ◽  
Initial Activity ◽  
Reaction Conditions ◽  
Bead Size ◽  
Optimum Ph ◽  
Optimum Ph And Temperature

A maltooligosaccharide-forming amylase from B circulans GRS 313 was immobilized by entrapment in calcium alginate beads. The immobilized activity was affected by the size of the bead and bead size of 2mm was found to be most effective for hydrolysis. Kinetics constants, Km and Vmax were estimated and were found to be affected by the bead size. The catalytic activity of the enzyme was studied in presence of various starchy residues and metal ions. HgCl2, CuSO4 and FeCl3 caused inhibition of the enzyme. The reaction conditions, pH and temperature, was optimized using response surface methodology. At the optimum pH and temperature of 4.9 and 57ºC, the apparent activity was 25.6U/g of beads, resulting in almost 2-fold increase in activity. The immobilized enzyme showed a high operational stability by retaining almost 85% of the initial activity after seventh use.

scholarly journals Optimal Conditions For Production Acidic D-Xylanase By Aspergillus niger in Submerged Fermentation

2011 ◽  
Vol 5 (3) ◽  
pp. 14-21
Author(s):  
Muhamed Omar Abdulatif ◽  
Hyder H. Assmaeel ◽  
Raghad kadhim Obeid ◽  
Ayat Adnan Abbas
Keyword(s):  
Aspergillus Niger ◽  
Rice Husk ◽  
Enzyme Production ◽  
Inoculum Size ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Xylanase Production ◽  
Primary Isolation ◽  
Optimum Ph ◽  
Optimum Period

he Xylanase producing strain Aspergillus niger was isolated from soil on potato dextrose agar in the presence of xylan as its first substrate for primary isolation, and then grown under liquid medium fermentation in the presence of crude xylan (rice husk) to produce D-Xylanase. the optimum conditions were determined as follows: the Optimum pH for xylanase production was found pH 5.0, xylanase was induced by xylan (rice husk) 0.1% and the production was (61.221 U/ml) and nitrogen source Yeast extract recorded highest enzyme production( 89.71 U/ml), and repressed by carbon source xylose the highest enzyme production (88.69 U/ml). The optimum temperature was 40°с for xylanase production was (35.15 U/ml), the optimum period after 7 days of incubation was (52.33 U/ml) ,the optimum substrate concentration 0.1% was (45.95 U/ml), and the optimum inoculum size was 1 x 106 (spore /ml) recorded (57.19 U/ml ).

scholarly journals Application of free and immobilized laccase for removal and detoxification of fluoroquinolones from aqueous solution

2020 ◽  
Keyword(s):  
Aqueous Solution ◽  
Trametes Versicolor ◽  
Storage Stability ◽  
Hydroxybenzoic Acid ◽  
Bacterial Strains ◽  
Covalent Bonds ◽  
Immobilized Laccase ◽  
And Storage

<p>Laccase from Trametes versicolor was immobilized by covalent bonds formation on CPC silica carriers. Elimination of two floroqinolone (FQ); enrofloxacine (ENR) and flumequine (FLU) using laccase in both free and immobilized form in the absence and presence of 1-hydroxybenzotriazole (HBT) and 4-Hydroxybenzoic acid (HBA) as mediators was investigated. Temperature, pH and storage stability of immobilized laccase was significantly improved compare to free laccase. In the absence of a laccase mediator, the initial concentrations of 50 mg L–1 of ENR and FLU decreased by 19 % and 28 %, respectively, after 6 h treatment using the immobilized laccase, while, the removal percentages were increased to 98 % and 96 %, respectively, when the immobilized laccase was used in presence of HBT. Whereas, the removal percentages of ENR and FLU were increased to 97 % and 88 %, respectively, when the immobilized laccase was used in presence of HBA. After twenty runs of the enzymatic elimination (laccase-HBT system) of ENR and FLU, the immobilized laccase exhibited the relative removal of 17.63 % and 15.62 %, respectively. The results of microtoxicity test (growth inhabitation percentage of six bacterial strains) showed a significant decrease in toxicity of the laccase-treated ENR and FLU solution.</p>

The assay and partial characterization of 3β-hydroxysteroid sulfotransferase of the hamster epididymis

1985 ◽  
Vol 63 (1) ◽  
pp. 71-76 ◽  
Author(s):  
M. Bouthillier ◽  
G. Bleau ◽  
A. Chapdelaine ◽  
K. D. Roberts
Keyword(s):  
Organic Phase ◽  
Enzyme Preparation ◽  
Enzymatic Reaction ◽  
Partial Characterization ◽  
Optimal Conditions ◽  
Steroid Nucleus ◽  
Optimum Ph ◽  
High Concentrations

Using a partially purified enzyme preparation obtained from hamster epididymis, a simple assay has been developed to measure the sulfurylation of dehydroisoandrosterone (DHA) and desmosterol in the presence of 3′-phosphoadenosine 5′-phospho[35S]sulfate ([35S]PAPS). After stopping the enzymatic reaction with methanol and KCl, the 35S-labelled steroid sulfates are readily extracted into an organic phase. Optimal conditions for the sulfurylation of the two steroids were compared; optimum pH is 8.7 for DHA and 9.8 for desmosterol. Sulfoconjugation of desmosterol increases with magnesium concentrations up to 6 mM, while 40 mM concentrations of the divalent ion are required for the optimal sulfurylation of DHA. Maximum sulfurylation of these steroids requires the presence of 15 mM cysteine. Michaelis–Menten kinetics are observed with DHA which has an apparent Km of 32 μM, while desmosterol inhibits sulfotransferase activity at high concentrations. Saturation of the enzyme with PAPS results in an allosteric behaviour. Only the 3β-hydroxyl function of the steroid nucleus appears to be an appropriate sulfate acceptor for the epididymal hydroxysteroid sulfotransferase.

KINETIC STUDIES ON ACID PHOSPHATASE IN TRIBOLIUM CONFUSUM DUVAL

1964 ◽  
Vol 42 (12) ◽  
pp. 1769-1775 ◽  
Author(s):  
K. D. Chaudhary ◽  
S. Moorjani ◽  
A. Lemonde
Keyword(s):  
Kinetic Studies ◽  
Final Concentration ◽  
Tribolium Confusum ◽  
Metallic Ions ◽  
Optimal Conditions ◽  
Optimum Temperature ◽  
Apparent Effect ◽  
Michaelis Constant ◽  
Optimum Ph ◽  
Zero Order Reaction

The biochemical characteristics of acid phosphomonoesterase in Tribolium confusum homogenate have been determined. Zero-order reaction occurs for 30 minutes, with 10−3 M final concentration of phenyl phosphate at an optimum pH of 6.4. Michaelis constant (Km) under the optimal conditions is 6.34 × 10−3 M. Maximum enzyme activity is obtained at 40 °C, and the activation energy (ΔE) is 13,000 cal/mole, within the limits of optimum temperature. Inorganic phosphate inhibits competitively and Ki value is 3.45 × 10−3 M. Partial inhibition by fluoride is shown. Apparent effect of metallic ions also has been demonstrated.Comparison of these results with those reported in the literature for several other species of insects, as well as with those in certain mammalian systems, has been discussed.

scholarly journals Purification and Characterization of a Feruloyl Esterase from the Intestinal Bacterium Lactobacillus acidophilus

2004 ◽  
Vol 70 (4) ◽  
pp. 2367-2372 ◽  
Author(s):  
Xiaokun Wang ◽  
Xin Geng ◽  
Yukari Egashira ◽  
Hiroo Sanada
Keyword(s):  
Lactobacillus Acidophilus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Hydrophobic Interaction Chromatography ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Feruloyl Esterase ◽  
Intestinal Bacterium ◽  
Optimum Ph ◽  
Optimum Ph And Temperature

ABSTRACT Dietary ferulic acid (FA), a significant antioxidant substance, is currently the subject of extensive research. FA in cereals exists mainly as feruloylated sugar ester. To release FA from food matrices, it is necessary to cleave ester cross-linking by feruloyl esterase (FAE) (hydroxycinnamoyl esterase; EC 3.1.1.73). In the present study, the FAE from a human typical intestinal bacterium, Lactobacillus acidophilus, was isolated, purified, and characterized for the first time. The enzyme was purified in successive steps including hydrophobic interaction chromatography and anion-exchange chromatography. The purified FAE appeared as a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular mass of 36 kDa. It has optimum pH and temperature characteristics (5.6 and 37°C, respectively). The metal ions Cu2+ and Fe3+ (at a concentration of 5 mmol liter−1) inhibited FAE activity by 97.25 and 94.80%, respectively. Under optimum pH and temperature with 5-O-feruloyl-l-arabinofuranose (FAA) as a substrate, the enzyme exhibited a K m of 0.0953 mmol liter−1 and a V max of 86.27 mmol liter−1 min−1 mg−1 of protein. Furthermore, the N-terminal amino acid sequence of the purified FAE was found to be A R V E K P R K V I L V G D G A V G S T. The FAE released FA from O-(5-O-feruloyl-α-l-arabinofuranosyl)-(1→3)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose (FAXX) and FAA obtained from refined corn bran. Moreover, it released two times more FA from FAXX in the presence of added xylanase.

Characteristics of the major DNA polymerases found during early and late maize germination

1988 ◽  
Vol 66 (6) ◽  
pp. 1186-1191 ◽  
Author(s):  
Alejandra Vazquez ◽  
Jorge Vazquez-Ramos
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerases ◽  
Absolute Requirement ◽  
Optimum Ph ◽  
Embryo Axes ◽  
The Difference ◽  
Alpha Type ◽  
Degree Of Purification ◽  
Optimum Ph And Temperature

Two types of DNA synthesis have been detected during maize germination (0–24 h). To determine if the difference in these two types of synthesis was due to the presence of distinct DNA polymerases, we partially isolated and characterized the enzymes present at 3 (early) and 24 (late) h of germination. The material used was embryo axes. The result indicates that at both 3 and 24 h, enzymes are similar with regard to optimum pH and temperature, absolute requirement of Mg2+ (12 mM), and stimulation by KCl (50 mM). They are also equally inhibited by N-ethylmaleimide and cytosine-β-D-arabinofuranoside. These facts would classify the enzymes as alpha type; however, the enzymes differ in their sensitivity to aphidicolin and the degree of purification. The nature of the enzymes is discussed.

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