Peningkatan Stabilitas Termal Enzim α-Amilase dari Bacillus subtilis ITBCCB148 dengan Amobilisasi Menggunakan Zeolit

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Yandri ◽  
Fathaniah Sejati ◽  
Tati Suhartati
Keyword(s):  
Thermal Stability ◽  
Bacillus Subtilis ◽  
Immobilized Enzyme ◽  
Specific Activity ◽  
Residual Activity ◽  
Stability Test ◽  
Optimum Temperature ◽  
Before And After ◽  
Cation Exchange Column ◽  
Thermal Stability Of

The objective of the research is to increase the thermal stability of -amylase from Bacillus subtilis ITBCCB148 by immobilization using zeolite. For that reason, firstly we need to produce, isolate, and purify the enzyme. The purification of the enzyme was conducted by the following steps: fractionation with ammonium sulphate, dialysis, and CM-cellulose cation exchange column chromatography. The purified enzyme was immobilized using zeolite. The success in immobilization of the enzyme was evaluated by comparing the thermal stability of the enzyme before and after immobilization. Activity of α-amylase was determined by the Mandels and Fuwa method. The protein content was determined based on the method by Lowry. The results showed that the specific activity of purified enzyme was 2473.7 U / mg, increased 19 times compared to crude extract of enzyme having specific activity of 1285.9 U / mg. The purified enzyme has the optimum temperature at 65ºC, while the immobilized enzyme has the optimum temperature at 75ºC. The thermal stability test of the purified enzyme at 65ºC for 100 minutes showed the purified enzyme having residual activity of 20%; t 1 / 2 = 30 min, k i = 0.023 min -1 and ΔGi = 103.65 kJ mol -1 . The thermal stability test of the immobilized enzyme at 65ºC for 100 minutes showed that the immobilized enzyme had residual activity of 40%; t 1/ 2 = 49 min, k i = 0.014 min -1 and ΔGi = 105.03 kJ mol -1 . Immobilization using zeolite has succeeded in increasing the thermal stability of enzyme by 1.64 times compared to the purified enzyme, which is indicated by the decreasing of k i value, the increase of half-life and denaturation energy change (ΔGi).

scholarly journals Increasing Stability of a-amylase Obtained from Bacillus subtilis ITBCCB148 by Immobilization with Chitosan

2020 ◽  
Vol 10 (2) ◽  
pp. 155-161
Author(s):  
Yandri Yandri ◽  
Tati Suhartati ◽  
Heri Satria ◽  
Arum Widyasmara ◽  
Sutopo Hadi
Keyword(s):  
Thermal Stability ◽  
Bacillus Subtilis ◽  
Half Life ◽  
Thermodynamic Data ◽  
Immobilized Enzyme ◽  
Residual Activity ◽  
Optimum Temperature ◽  
Chitosan Matrix ◽  
T Values ◽  
Thermal Stability Of

In this research, the immobilization of α-amylase from Bacillus subtilis ITBCCB148 by crosslinking method on chitosan matrix has been performed. This research aims to know the effect of immobilization on the thermal stability of α-amylase. The results showed that the native α-amylase has an optimum temperature of  65oC, KM = 1.6 mg mL-1 substrate, and Vmax = 39.7 µmol mL-1 min-1. The immobilized α-amylase has optimum temperature of 75oC, KM = 3.5 mg mL-1 substrate, and Vmax = 7.05 µmol mL-1 min-1. The residual activity of the native and immobilized enzyme on thermal stability test at 65oC for 80 minutes was 58% and 86.15%, respectively. The immobilized enzyme can be reused up to six repeated cycles.The thermodynamic data of native enzyme was t½ = 113.6 min, ki = 6.1x10-3 min-1, and ΔGi = 107.3 kJ mol-1, while the immobilized enzyme was t½ = 433.1 min, ki= 1.6x10-3 min-1, and ΔGi 111.1 kJ mol-1. Based on the decrease of ki, and the increase of ΔGi and half-life(t½) values, the immobilization of α-amylase with chitosan can increase the thermal stability of this enzyme.

scholarly journals Immobilization of α - amylase from locale bacteria isolate Bacillus subtilis ITBCCB148 with diethylaminoethyl cellulose (DEAE-Cellulose)

2010 ◽  
Vol 7 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Yandri. Yandri ◽  
Tati Suhartati ◽  
Sutopo Hadipo Hadi
Keyword(s):  
Thermal Stability ◽  
Bacillus Subtilis ◽  
Immobilized Enzyme ◽  
Storage Temperature ◽  
Residual Activity ◽  
Deae Cellulose ◽  
Ionic Exchange ◽  
Optimum Temperature ◽  
Diethylaminoethyl Cellulose ◽  
Exchange Matrix

The thermal stability increase of a-amylase obtained from locale bacteria isolate Bacillus subtilis ITBCCB148 was achieved by immobilization process using an ionic exchange matrix of DEAE-Cellulose. The result showed that the immobilized enzyme has an optimum temperature of 60°C; KM 14.8 mL substrate and Vmax 42.4 U/mL. The thermal stability storage temperature of 60°C, pH 9.0 and 60 minutes demonstrated the immobilized enzyme has residual activity of 28.1%; ki = 0.0224 min.-1; and ΔGi = 103.7 kJ mol-1. Although the immobilized enzyme’s thermal stability was only increased 1.5 times, at higher temperatures, it was much more stable than the native enzyme.

Milk-Coagulating Extract Produced from Solanum aethiopicum Shum Fruits: Multivariate Techniques of Preparation, Thermal Stability and Effect on Milk Solids Recovery in Curd

2014 ◽  
Vol 10 (2) ◽  
pp. 211-222 ◽  
Author(s):  
Valentin Désiré Guiama ◽  
Robert Germain Beka ◽  
Esther Ngah ◽  
David Gabriel Libouga ◽  
Dominique Vercaigne-Marko ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Multivariate Techniques ◽  
Extraction Temperature ◽  
Optimum Temperature ◽  
Solanum Aethiopicum ◽  
Fruit Maturity ◽  
Nacl Concentration ◽  
Actual Yield ◽  
Milk Solids ◽  
Thermal Stability Of

Abstract This study investigated a novel procedure of Solanum aethiopicum Shum fruits extract (SASFE) preparation using multivariate experimental designs as factorial and Box–Behnken. The thermal stability of optimized extract as well as its influence on the milk solids in curd was determined. The results showed that extraction time, fruit maturity and pH did not affect significantly SASFE preparation, while the amount of fruits, extraction temperature and NaCl concentration of extractant had a significant effect (p < 0.05). The greatest coagulant index was obtained under the following conditions: 12.5% of fruits, 25°C of extraction temperature and 4% NaCl concentration of extractant. It was thermosensitive and exhibited optimum temperature at 50°C. There was no statistical difference between SASFE and calf rennet in terms of solids yield in curd, estimated yield and actual yield. On the basis of these results, SASFE can be used as a vegetable alternative to calf rennet.

scholarly journals ENHANCED ENZYMATIC ACTIVITY OF STREPTOMYCES GRISEOPLANUS L-ASPARGINASE VIA ITS INCORPORATION IN AN OIL-BASED NANOCARRIER

2020 ◽  
pp. 203-210
Author(s):  
ABEER A. EL-HADI ◽  
HANAN MOSTAFA AHMED ◽  
RANIA A. ZAKI ◽  
AMIRA MOHAMED MOHSEN
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Enzymatic Activity ◽  
Specific Activity ◽  
Residual Activity ◽  
Tween 80 ◽  
Biochemical Properties ◽  
Lymphocytic Leukemia ◽  
Tween 20 ◽  
Ph Range

Objective: L-asparaginase (L-asp) is a vital enzyme used as a therapeutic agent in combination with other drugs in the treatment of acute lymphoma, melanosarcoma and lymphocytic leukemia. Immobilization of enzymes through loading on nanoemulsion (NE) results in some advantages such as enhancing their stability and increasing their resistance to proteases. Aim of the present study is to formulate L-asp loaded nanoemulsion to enhance its efficiency and thermal stability. Methods: Nanoemulsion loaded with L-asp crude extract (specific activity 13.23U/mg protein) was prepared employing oleic acid as oil, tween 20/tween 80 as surfactants and propylene glycol (PG) as co-surfactant. L-asp loaded NE underwent several thermodynamic stability studies and the optimized formulae were further examined for their biochemical properties and thermal stability. Results The developed formulations were spherical in shape and their sizes were in the nanometric dimensions with negatively charged zeta potential values. Upon comparing the enzyme activity of L-asp loaded NE employing tween 20 (F1) or tween80 (F4) at different concentrations, the results revealed that F4 NE showed higher enzymatic activity [323 U/ml] compared to F1 NE [197 U/ml] at the same concentration. The nanosized immobilized L-asp was more stable in the pH range from 8 to 8.5 as compared to free L-asp. The immobilized enzyme preserved about 59.11% of its residual activity at 50 °C; while free L-asp preserved about 33.84%. Conclusion: In the view of these results, NE composed of oleic acid, tween 80 and PG represents a promising dosage form for enhancing the activity and stability of Streptomyces griseoplanus L-asp.

scholarly journals Polystyrene/Montmorillonite Nanocomposites: Study of the Morphology and Effects of Sonication Time on Thermal Stability

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Mashael Alshabanat ◽  
Amal Al-Arrash ◽  
Waffa Mekhamer
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Solution Method ◽  
Sonication Time ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polystyrene Matrix ◽  
Before And After ◽  
Silicate Layers ◽  
Thermal Stability Of

Polymer nanocomposites of polystyrene matrix containing 10% wt of organo-montmorillonite (organo-MMT) were prepared using the solution method with sonication times of 0.5, 1, 1.5, and 2 hours. Cetyltrimethylammonium bromide (CTAB) is used to modify the montmorillonite clay after saturating its surface with Na+ions. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the montmorillonite before and after modification by CTAB. The prepared nanocomposites were characterized using the same analysis methods. These results confirm the intercalation of PS in the interlamellar spaces of organo-MMT with a very small quantity of exfoliation of the silicate layers within the PS matrix of all samples at all studied times of sonication. The thermal stability of the nanocomposites was measured using thermogravimetric analysis (TGA). The results show clear improvement, and the effects of sonication time are noted.

Thermal Stability Study of the Interconnect System with Fluorinated Silicate Glass as IMD Layers

1997 ◽  
Vol 476 ◽  
Author(s):  
Weidan Li ◽  
Wilbur Catabay
Keyword(s):  
Thermal Stability ◽  
Oxide Film ◽  
Silicate Glass ◽  
Elevated Temperatures ◽  
Stability Test ◽  
Silicon Nitride Film ◽  
Barrier Materials ◽  
Device Reliability ◽  
Interconnect System ◽  
Thermal Stability Of

AbstractWhile fluorinated silicate glass (FSG) has been proposed for low k inter-metal dielectric (IMD) applications in a multi-level interconnect system either as the only IMD material, or as one of the materials for a multi-layer IMD system, thermal stability of the FSG film and its impact on device reliability remain a concern for this application. In this study, SIMS, SEM, and optical microscope analyses were carried out to evaluate the thermal stability of the FSG films and the possible reactions between FSG and metals. It was observed that at elevated temperatures fluorine tends to diffuse into an undoped oxide film rather than be desorbed. The data indicate that F diffuses 3.5 times faster in a silicon oxide film than in a silicon nitride film. Sub-half micron devices were processed with FSG as IMD layers. The devices were tested using an intensive thermal stability test methodology. A TiSi2 reaction with F which diffused from the FSG film was observed under optical microscopy. This reaction caused TiSi2 delamination. Electrical characterization of devices was performed before and after the thermal stability test. Although the device performance did not change greatly, the reaction certainly affects the long term device reliability (vide infra). Barrier materials were investigated to solve the F diffusion problem. With the proper diffusion barrier, the problem of the fluorine reaction with TiSi2 and subsequent metal blistering was eliminated.

Thermal Aging Analysis of Rubber Used for Fabric Expansion Joints

2013 ◽  
Vol 807-809 ◽  
pp. 2718-2721
Author(s):  
Li Na Ma ◽  
Yu Zeng Zhao ◽  
Hong Hua Ge ◽  
Kuai Ying Liu
Keyword(s):  
Thermal Stability ◽  
Thermal Aging ◽  
Inert Atmosphere ◽  
Expansion Joints ◽  
Chemical Structures ◽  
Before And After ◽  
The Difference ◽  
Ethylene Propylene Diene Terpolymer ◽  
Thermal Stability Of ◽  
Accelerated Thermal Aging

Several kinds of rubbers used for fabric expansion joints were studied by Thermogravimetric analysis under inert atmosphere before and after artificial accelerated thermal aging. The results showed that because of the difference of the chemical structures, the rubber aging is different. And the thermal stability of Polytetrafluoroethylene (PTFE) was obviously higher than that of other two kinds of rubbers, ethylene-propylene-diene-terpolymer rubber (EPDM) and fluororubber.

THE EFFECTS OF TEMPERATURE UPON PANCREATIC AMYLASE IN SELECTED REPTILES AND AN AMPHIBIAN

1967 ◽  
Vol 45 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Yvette Abrahamson ◽  
Michael Maher
Keyword(s):  
Thermal Stability ◽  
Amylase Activity ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Pancreatic Amylase ◽  
Optimum Temperature ◽  
Preferred Temperatures ◽  
Effects Of Temperature ◽  
Subcellular Level ◽  
Thermal Stability Of

The effect of temperature on pancreatic amylase was studied on three species of reptiles and one amphibian. Pancreata were removed from the animals, homogenized, and assayed for amylase activity by the Caraway procedure. Assays were conducted at various temperatures to determine the optimum temperature of activity and the maximum temperature for thermal stability of pancreatic amylase. It appears that between reptiles and amphibians, and also among species of reptiles, there are thermally dependent differences at the subcellular level which are similar to the differences in the preferred temperatures of the animals.

scholarly journals Certification of a New Batch of the Industry Reference Standard for the Control of Specific Activity and Thermal Stability of Live Plague Vaccine

2018 ◽  
Vol 18 (4) ◽  
pp. 262-267 ◽  
Author(s):  
I. V. Kasina ◽  
S. A. Alekseeva ◽  
O. V. Fadeykina ◽  
T. I. Nemirovskaya ◽  
R. A. Volkova
Keyword(s):  
Thermal Stability ◽  
Specific Activity ◽  
Quality Parameters ◽  
Microbial Cell ◽  
Average Weight ◽  
Statistical Interpretation ◽  
Test Results ◽  
Reference Standard ◽  
Plague Vaccine ◽  
Thermal Stability Of

In accordance with the State Pharmacopoeia (SPh) requirements for live plague vaccine, a reference standard has to be used when testing the specific activity and thermal stability of plague vaccine commercial batches in order to assess the consistency and acceptability of the test results. Since there is no international reference standard for plague vaccine, the certification of a new batch of the industry reference standard (IRS) of live plague vaccine in terms of the above-mentioned quality parameters is an urgent challenge. Therefore, a certification programme for the industry reference standard was developed that establishes the design and scope of testing required to obtain statistically significant results. A candidate IRS was represented by a commercial batch of the product meeting the specification requirements for live plague vaccine. The certification parameters were: «Specific activity: microbial cell concentration», «Specific activity: live microbial cell percentage» and «Thermal stability». The article presents the results of the certification of a new batch of the live plague vaccine IRS, detailed evaluation of the candidate IRS in terms of: «Average weight and uniformity of weight», «Loss on drying», and statistical interpretation of the test results. It also summarises the results of the product testing in terms of «Specific activity: immunogenicity». The results of application of the previous batch of the live plague vaccine IRS (OSO 42-28-392-2013) and the results of monitoring the stability of its certification parameters demonstrated that the IRS shelf life could be extended by 6 months relative to the established period (from 2 to 2.5 years). All the certified and additional characteristics are reflected in the official documents for the scientific/technological product — live plague vaccine IRS, OSO 42-28-392-2017: passport, labelling and patient information leaflet.

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