scholarly journals Production and Partial Characterization of High Molecular Weight Extracellular α-amylase from Thermoactinomyces vulgaris Isolated from Egyptian Soil

2011 ◽  
Vol 60 (1) ◽  
pp. 65-71 ◽  
Author(s):  
M.I. ABOU DOBARA ◽  
A.K. EL-SAYED ◽  
A.A. EL-FALLAL ◽  
N.F. OMAR
Keyword(s):  
Nitrogen Sources ◽  
Maximum Activity ◽  
The Other ◽  
Alpha Amylase ◽  
Optimum Ph ◽  
Initial Ph ◽  
Organism Growth ◽  
Thermoactinomyces Vulgaris ◽  
Egyptian Soil

Optimizing production of alpha-amylase production by Thermoactinomyces vulgaris isolated from Egyptian soil was studied. The optimum incubation period, temperature and initial pH of medium for organism growth and enzyme yield were around 24 h, 55 degrees C and 7.0, respectively. Maximum alpha-amylase activity was observed in a medium containing starch as carbon source. The other tested carbohydrates (cellulose, glucose, galactose, xylose, arabinose, lactose and maltose) inhibited the enzyme production. Adding tryptone as a nitrogen source exhibited a maximum activity of alpha-amylase. Bactopeptone and yeast extract gave also high activity comparing to the other nitrogen sources (NH4CI, NH4NO3, NaNO3, KNO3, CH3CO2NH4). Electrophoresis profile of the produced two alpha-amylase isozymes indicated that the same pattern at about 135-145 kDa under different conditions. The optimum pH and temperature of the enzyme activity were 8.0 and 60 degrees C, respectively and enzyme was stable at 50 degrees C over 6 hours. The enzyme was significantly inhibited by the addition of metal ions (Na+, Co2+ and Ca2+) whereas CI- seemed to act as activator. The enzyme was not affected by 0.1 mM EDTA while higher concentration (10 mM EDTA) totally inactivated the enzyme.

scholarly journals Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua)

2018 ◽  
pp. 52-58
Keyword(s):  
Specific Activity ◽  
Chenopodium Quinoa ◽  
Maximum Activity ◽  
Alpha Amylase ◽  
Partial Purification ◽  
Chemical Hydrolysis ◽  
Germination Process ◽  
Sds Page ◽  
Global Population

Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua) Partial Purification and Characterization of Alpha Amylase from germinated grains from Chenopopdium quinoa (Quinua) Melissa Bedón Gómez, Oscar Nolasco Cárdenas, Carlos Santa Cruz C. y Ana I. F. Gutiérrez Román Universidad Nacional Federico Villarreal, Facultad de Ciencias Naturales y Matemática, Laboratorio de Bioquímica y Biología Molecular, Jr. Río Chepén S/N, El Agustino. Telefax: 362 - 3388 DOI: https://doi.org/10.33017/RevECIPeru2013.0007/ Resumen Las alfa amilasas son las enzimas más estudiadas e importantes en el campo biotecnológico e industrial; ya que han reemplazado por completo la hidrólisis química del almidón. Estas enzimas son imprescindibles en la elaboración de productos alimenticios, combustibles, medicamentos y detergentes con la finalidad de optimizar procesos y conservar el medio ambiente. La α-amilasa puede ser purificada de diferentes organismos como plantas, animales, hongos y bacterias; actualmente un gran número de α-amilasas bacterianas en especial del género Bacillus están disponibles comercialmente y son las más utilizadas en las industrias. Sin embargo, la producción de éstas no satisfacen los requerimientos industriales en el mundo; ya que, la demanda de esta enzima se ha incrementado en los últimos dos años y el empleo de α-amilasas bacterianas ha provocado alergias afectando al 15% de la población a nivel mundial. . En este estudio, como fuente de α-amilasa se emplearon semillas de Chenopodium quinoa (quinua) var hualhuas blanca durante el proceso de germinación; esta enzima fue parcialmente purificada por precipitación con sulfato de amonio obteniendo una actividad específica final de 35.60U/mg y un grado de purificación de 5 veces. La purificación fue confirmada por SDS-PAGE, encontrando un peso molecular de 44kDa. La actividad enzimática se evaluó mediante el método de Miller mostrando máxima actividad a pH 7 y a temperatura de 37ºC. La linealización de Lineweaver-Burk nos dio un Km de 16mg/mL y Vmax de 100µM de maltosa/min. Por lo tanto, esta caracterización reúne los pre-requisitos necesarios para la aplicación en la industria. Descriptores: Chenopodium quinoa, alfa amilasa, germinación, purificación parcial. Abstract The alpha amylases are the enzymes most studied and important in biotechnology and industry; because they have completely replaced the starch’s chemical hydrolysis. These enzymes are essential in the food production, medicines and detergents in order to optimize processes and conserve the environment. The α-amylase can be isolated from different organisms such as plants, animals, fungi and bacteria, now a large number of bacterial α-amylases especially from genus Bacillus are commercially available and they are the most used in industry. However, the production of these do not meet industry requirements in the world, because the demand for this enzyme has increased in the last two years and the use of bacterial α-amilase has caused allergies affecting the 15% of the global population. In this study, as a source of α-amylase used the seeds from Chenopodium quinoa (quinoa). Var. white hualhuas during the germination process, this enzyme was partially purified by ammonium sulfate precipitation to obtain a final specific activity of 35.60U/mg, and a grade of purification of 5 times. The purification was confirmed by SDS-PAGE, where the molecular weight was 44kDa. The enzyme activity was evaluated by Miller method showing maximum activity at pH 7 and 37ºC. The Lineweaver-Burk linearization shows a Km of 16mg/mL and Vmax of 100μM the maltose / min. Therefore, these characterizations meet the prerequisites need for industry. Keywords: Chenopodium quinoa; alpha amylase; germination; partial purification

PURIFICATION AND PARTIAL CHARACTERIZATION OF THERMOACTINOMYCES VULGARIS AMYLASES

1967 ◽  
Vol 13 (9) ◽  
pp. 1157-1163 ◽  
Author(s):  
M. J. Kuo ◽  
P. A. Hartman
Keyword(s):  
Ion Exchange ◽  
Column Chromatography ◽  
Maximum Rate ◽  
Amylase Activity ◽  
Enzyme Preparations ◽  
Ph Values ◽  
Ion Exchange Column ◽  
Optimum Ph ◽  
Thermoactinomyces Vulgaris

An α-amylase from Thermoactinomyces vulgaris has been purified about 100-fold. Its optimum pH was between 5.9 and 7.0, and the maximum rate was achieved at 60 °C. In the absence of substrate, the enzymes were more stable at pH 5.9 than at higher or lower pH values; inactivation was rapid at pH 7.0. Temperatures of 70 °C or greater also caused rapid denaturation of the enzyme in the absence of substrate. Three major peaks of amylase activity were detected when purified enzyme preparations were passed through Sephadex G-75 columns. At least two of these amylases were interconvertible. Four or five T. vulgaris proteinases also were separated, using ion exchange column chromatography.

Characterization of amoA and hao Genes Responsible for Ammonia Oxidation Reaction in CANON System

2011 ◽  
Vol 183-185 ◽  
pp. 1014-1019
Author(s):  
Hai Yan Zou ◽  
Jun Li Huang ◽  
Fang Fang ◽  
Jin Song Guo
Keyword(s):  
Nitrogen Removal ◽  
Oxidation Reaction ◽  
High Efficiency ◽  
Ammonia Oxidation ◽  
Residual Activity ◽  
Maximum Activity ◽  
Ammonia Oxidizing Bacteria ◽  
Hydroxylamine Oxidoreductase ◽  
Optimum Ph

In this research the genes (amoA and hao) for ammonia monooxygenase (AMO) and hydroxylamine oxidoreductase (HAO) responsible for ammonia oxidation reaction in completely autotrophic nitrogen removal over nitrite process were cloned and sequenced, and the recombinant protein of AMO and HAO was expressed and characterized. The optimum temperature for AMO activity was 55 °C and more than 40% of the maximum activity was retained from 15-50 °C. The optimum pH for the enzyme was found to be pH 11.0. The highest activity for HAO was observed at 45 °C. More than 50% of the maximum activity was retained even at 55 °C. The dependence of HAO on pH was strong and only average 15% of residual activity left at pH ranging from 3.0-9.0. Study on the molecular and biochemistry properties of recombinant AMO and HAO will benefit for the manipulation of ammonia-oxidizing bacteria to achieve the goal of high efficiency of nitrogen removal.

scholarly journals Purification and characterization of amylase from local isolate Pseudomonas sp.SPH4

2012 ◽  
Vol 6 (1) ◽  
pp. 69-79
Author(s):  
Hala M. Ali ◽  
Ghazi M. Aziz
Keyword(s):  
Enzyme Activity ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Silver Ions ◽  
Enzyme Characterization ◽  
Maximum Activity ◽  
Mercury Ions ◽  
Local Isolate ◽  
Optimum Ph

The amylase produced from local isolate Pseudomonas sp. SPH4 was purified by precipitation with 30% saturation ammonium sulphate, followed by ion-exchange chromotography using DEAE-cellulose column, and Gel filtration using Sephacryl S-300 column.The two iso-enzymes (a, b) were purified to (2.83, 3.47) times in the last step with an enzymes yields of (32.36, 76.34)% respectively. Enzyme characterization of the two iso-enzymes indicated that the optimum pH for the two iso-enzymes a and b were (7, 7.5) respectively, while the optimum pH for the iso-enzymes stability were (6.5, 7) respectively. The maximum activity for iso-enzymes (a, b) appeared at 45ºC and stable for 15 min at 30-50ºC and lost approximately 50% of it's activity at rang above 75ºC. Enzyme characterization results showed that the chlorides of silver and mercury had inhibitory effect on enzyme activity, the remaining enzyme activity for the iso-enzymes (a, b) were (46.66, 36.36)% for silver ions and (41.33, 33.63)% for mercury ions at 5 mM respectively, and (28, 28.18)% for silver ions and (25.33, 19.09)% for mercury ions at 10 mM respectively. The iso-enzymes a and b were affected by chelating agent ethylene diamine tetra acetic acid (EDTA) at concentration 2mM the remaining activity (45.33, 43.63)% respectively, and 5mM the remaining activity (28, 28.18)% respectivily, and these iso-enzymes (a, b) refered to metalloenzymes. The iso-enzymes (a, b) were kept their activity when treated by reducing agent (2-mercaptoethanol) at 2 mM the remaining activity (92, 92.72)% respectively, and 5 mM the remaining activity (85.3, 89.09)% respectivily. The iso-enzymes (a, b) were kept their activity when treated by phenyl methyl sulphonyl fluoride (PMSF) at concentration 1mM the remaining activity (93.33, 90.90)% respectivily,and 5 mM the remaining activity (90.66, 87.27)% respectivily, and these indicated that these iso-enzymes didnot referred to serineamylases group.

scholarly journals Purification and characterization of alpha-amylases from the intestine and muscle of ascaris suum (Nematoda).

2001 ◽  
Vol 48 (3) ◽  
pp. 763-774 ◽  
Author(s):  
K Zółtowska
Keyword(s):  
Molecular Mass ◽  
Isoelectric Focusing ◽  
Ascaris Suum ◽  
Iodoacetic Acid ◽  
Maximum Activity ◽  
Alpha Amylase ◽  
Purification And Characterization ◽  
Muscle Enzyme ◽  
Sds Page

Alpha-Amylase (EC 3.2.1.1) was purified from the muscle and intestine of the parasitic helminth of pigs Ascaris suum. The enzymes from the two sources differed in their properties. Isoelectric focusing revealed one form of a-amylase from muscles with pl of 5.0, and two forms of amylase from intestine with pI of 4.7 and 4.5. SDS/PAGE suggested a molecular mass of 83 kDa and 73 kDa for isoenzymes of a-amylases from intestine and 59 kDa for the muscle enzyme. Alpha-Amylase from intestine showed maximum activity at pH 7.4, and the enzyme from muscle at pH 8.2. The muscle enzyme was more thermostabile than the intestinal alpha-amylase. Both the muscle and intestine amylase lost half of its activity after 15 min at 70 degrees C and 50 degrees C, respectively. The Km values were: for muscle amylase 0.22 microg/ml glycogen and 3.33 microg/ml starch, and for intestine amylase 1.77 microg/ml glycogen and 0.48 microg/ml starch. Both amylases were activated by Ca2+ and inhibited by EDTA, iodoacetic acid, p-chloromercuribenzoate and the inhibitor of a-amylase from wheat. No significant differences were found between the properties of a-amylases from parasites and from their hosts.

scholarly journals Purification and characterization of diacetyl-reducing enzymes from Staphylococcus aureus

1988 ◽  
Vol 251 (2) ◽  
pp. 461-466 ◽  
Author(s):  
I Vidal ◽  
J González ◽  
A Bernardo ◽  
R Martín
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
The Other ◽  
Purification And Characterization ◽  
High Affinity ◽  
Optimum Ph ◽  
Nad Oxidoreductase ◽  
The One

A method was developed to purify diacetyl-reducing enzymes from Staphylococcus aureus. Two enzymes capable of catalysing diacetyl reduction were isolated, neither of which turned out to be a specific diacetyl reductase. One of them is a lactate dehydrogenase similar to the one from Staphylococcus epidermidis, which accepts diacetyl, although poorly. The other one uses as coenzyme beta-NAD and reduces uncharged alpha-dicarbonyls with more than three carbon atoms (especially the alpha-diketones diacetyl and pentane-2,3-dione), producing the L(+) form of the corresponding alpha-hydroxycarbonyls. This enzyme has an Mr of 68,000 and is, most probably, a monomer. Its optimum pH is 6.0. Its shows a high affinity for NADH and a rather low one for diacetyl, which, at least in vitro, does not seem to be as good a substrate as pentane-2,3-dione. We propose for it the systematic name L-alpha-hydroxyketone: NAD+ oxidoreductase and the recommended name of alpha-diketone reductase (NAD). We also suggest that the diacetyl reductase entry in the I.U.B. classification be suppressed.

scholarly journals Purification, Characterization of L-Methioninase from Candida tropicalis, and Its Application as an Anticancer

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Helmy Selim ◽  
El-Zahraa Karm Eldin ◽  
Moataza Mahmoud Saad ◽  
El-Sayed Eliwa Mostafa ◽  
Yosrea Hassan Shetia ◽  
...  
Keyword(s):  
Candida Tropicalis ◽  
Anticancer Agent ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Tumor Cell Lines ◽  
Sds Page ◽  
Optimum Ph ◽  
Ph Range

The aim of the present study is to purify L-methioninase from Candida tropicalis 34.19-fold with 27.98% recovery after ion exchange chromatography followed by gel filtration. The purified enzyme revealed a single band on SDS-PAGE gel with a molecular weight of 46 KDa. Its optimum temperature was 45 to 55 and thermal stability was 55°C for 15 min. The enzyme had optimum pH at 6.5 and stability at a pH range of 5.5 to 7.0 for 24 hr. The maximum activity was observed with substrate concentration of 30 µM and Km was 0.5 mM. The enzyme was strongly inhibited by Cd+2 and Cu+2 while it was enhanced by Na+, Ni+2, and Mg+2 at 10 mM while Ca+2 had slight activation at 20 mM. In addition, the potential application of the L-methioninase as an anticancer agent against various types of tumor cell lines is discussed.

scholarly journals Characterization of β-glucosidase of Lactobacillus plantarum FSO1 and Candida pelliculosa L18 isolated from traditional fermented green olive

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yahya Rokni ◽  
Houssam Abouloifa ◽  
Reda Bellaouchi ◽  
Ismail Hasnaoui ◽  
Sara Gaamouche ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Lactobacillus Plantarum ◽  
Maximum Activity ◽  
Table Olives ◽  
Nacl Concentration ◽  
Initial Ph ◽  
Phenolic Glucoside ◽  
Production Value ◽  
Green Olive

Abstract Background Oleuropein, the main bitter phenolic glucoside responsible for green olive bitterness, may be degraded by the β-glucosidase enzyme to release glucose and phenolic compounds. Results Lactobacillus plantarum FSO1 and Candida pelliculosa L18 strains, isolated from natural fermented green olives, were tested for their β-glucosidase production and activity at different initial pH, NaCl concentrations, and temperature. The results showed that strains produced extracellular and induced β-glucosidase, with a molecular weight of 60 kD. The strains demonstrated their biodegradation capacity of oleuropein, associated with the accumulation of hydroxytyrosol and other phenolic compounds, resulting in antioxidant activity values significantly higher than that of ascorbic acid. The highest production value of β-glucosidase was 0.91 U/ml obtained at pH 5 and pH 6, respectively for L. plantarum FSO1 and C. pelliculosa L18. The increase of NaCl concentration, from 0 to 10% (w/v), inhibited the production of β-glucosidase for both strains. However, the β-glucosidase was activated with an increase of NaCl concentration, with a maximum activity obtained at 8% NaCl (w/v). The enzyme activity was optimal at pH 5 for both strains, while the optimum temperature was 45 °C for L. plantarum FSO1 and 35 °C for C. pelliculosa L18. Conclusions L. plantarum FSO1 and C. pelliculosa L18 strains showed their ability to produce an extracellular and induced β-glucosidase enzyme with promising traits for application in the biological processing of table olives.

scholarly journals Immobilization of Naringinase from Penicillium decumbens on Chitosan Microspheres for Debittering Grapefruit Juice

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4234 ◽  
Author(s):  
Joanna Bodakowska-Boczniewicz ◽  
Zbigniew Garncarek
Keyword(s):  
Grapefruit Juice ◽  
Immobilized Enzyme ◽  
Maximum Activity ◽  
Chitosan Microspheres ◽  
Optimum Ph ◽  
Potential Applicability ◽  
Km Value ◽  
Hydrolysis Of ◽  
Thermal Stability Of

Naringinase is an enzyme complex which exhibits α-l-rhamnosidase and β-d-glucosidase activity. This enzymatic complex catalyzes the hydrolysis of naringin (4′,5,7-trihydroxy flavanone 7-rhamnoglucoside), the main bittering component in grapefruit. Reduction of the level of this substance during the processing of juice has been the focus of many studies. The aim of the study was the immobilization of naringinase on chitosan microspheres activated with glutaraldehyde and, finally, the use of such immobilized enzyme for debittering grapefruit juice. The effect of naringinase concentration and characterization of the immobilized enzyme compared to the soluble enzyme were investigated. The maximum activity was observed at optimum pH 4.0 for both free and immobilized naringinase. However, the optimum temperature was shifted from 70 to 40 °C upon immobilization. The KM value of the immobilized naringinase was higher than that of soluble naringinase. The immobilization did not change the thermal stability of the enzyme. The immobilized naringinase had good operational stability. This preparation retained 88.1 ± 2.8% of its initial activity after ten runs of naringin hydrolysis from fresh grapefruit juice. The results indicate that naringinase immobilized on chitosan has potential applicability for debittering and improving the sensory properties of grapefruit juices.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

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