scholarly journals IMMOBILIZATION OF PAPAIN ON CHITOSAN

2010 ◽  
Vol 8 (3) ◽  
pp. 372-376
Author(s):  
Sari Edi Cahyaningrum ◽  
Narsito Narsito ◽  
Sri Juari Santoso ◽  
Rudiana Agustini
Keyword(s):  
Thermal Stability ◽  
Optimum Temperature ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Thermal Stability Of

In this study, papain was immobilized on chitosan with Mg(II) cosslinked agent. Studies on free and immobilized papain systems for determination of optimum pH, optimum temperatur, thermal stability and reusability were carried out. The results showed that free papain had optimum pH 6.5 and optimum temperature 55 °C while the immobile papain hadoptimum pH 8 and optimum temperature 80 °C. The thermal stability of the immobilized papain, relative to that of the free papain, was markedly increased. The immobilized papain can be reused for at least six times.   Keywords: papain, immobilization, chitosan

scholarly journals Immobilization of Isolated Lipase From Moldy Copra(Aspergillus Oryzae)

2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah
Keyword(s):  
Thermal Stability ◽  
Aspergillus Oryzae ◽  
Immobilized Lipase ◽  
Optimum Temperature ◽  
Adsorption Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Recovery Technique ◽  
Free Lipase

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

scholarly journals SCREENING DAN KARAKTERISASI PEKTINESTERASE SEBAGAI ENZIM POTENSIAL DALAM KLARIFIKASI SARI BUAH JERUK KEPROK GARUT (Citrus nobilis var.chrysocarpa)

2015 ◽  
Vol 35 (04) ◽  
pp. 422
Author(s):  
Rohula Utami ◽  
Esti Widowati ◽  
Arifah Rahayu
Keyword(s):  
Thermal Stability ◽  
Optimum Temperature ◽  
Citrus Pectin ◽  
Ph Optimum ◽  
Citrus Juice ◽  
Optimum Ph ◽  
Km Value ◽  
Screening Result ◽  
Optimum Ph And Temperature

The objective of this research was screening of pectinesterase (PE) producing bacteria which are potential in clarification of keprok garut citrus juice (Citrus nobilis var microcarpa) and characterization of the resulted pectinesterase (optimum pH and temperature, pH and thermal stability, KM and Vmaks). The screening result showed that enzyme of isolates AR2, AR 4, AR 6, and KK 2 was found to be a potential enzyme for clarification of keprok garut citrus juice. Enzyme pektinesterase of isolates AR 2, AR 4, AR 6, and KK 2 had optimum pH at 8; 7.5; 8.5; and 6.5 and stable at pH 4-9, 4-9, 6-9, and 3-8. The optimum temperature enzyme of isolates AR 2 and AR 6 were 55ºC and that of AR 4 and KK 2 were 60ºC. Enzyme of isolate AR 2 was stable at 30-50ºC and inactive at 80ºC, AR 4 and KK 2 were stable at 30-60ºC and inactive at 90ºC whereas AR6 was stable at 30-60ºC and still wasn’t inactive at 90ºC. KM value of isolates AR 2, AR 4, AR 6, and KK 2 were 0.604; 0.338; 0.971; and 0.392 mg/ml. Vmaks value of isolates AR 2, AR 4, AR 6, and KK 2 were 1.218; 0.826; 0.969; and 1.080 u/ml. Pectinesterase enzyme of isolates KK 2 was found to be the most potential enzyme for clarification of keprok garut citrus juice.Keywords: Clarification, enzyme, keprok garut citrus, pectin, pectinesterase ABSTRAKTujuan dari penelitian ini adalah untuk melakukan screening bakteri penghasil enzim pektinesterase (PE) yang berpotensi dalam proses klarifikasi sari buah jeruk keprok garut (Citrus nobilis var microcarpa) serta mengetahui karakteristik enzim pektinesterase yang dihasilkan (pH optimum, suhu optimum, kestabilan pH dan suhu, serta nilai KMdan Vmaks). Hasil screening didapatkan isolat AR 2, AR 4, AR 6, dan KK 2 sebagai isolat penghasil enzim pektinesterase yang berpotensi dalam proses klarifikasi sari buah jeruk keprok garut. Aktivitas enzim pektinesterase isolat AR 2, AR 4, AR 6 dan KK 2 berturut-turut optimum pada pH 8; pH 7,5; pH 8,5; dan pH 6,5, serta stabil pada pH 4-9, pH4-9, pH 6-9, dan pH 3-8. Suhu optimum enzim pektinesterase isolat AR 2, AR 4, AR 6, dan KK 2 berturut-turut adalah 55ºC, 60ºC, 55ºC, dan 60ºC. Enzim pektinesterase isolat AR 2 stabil pada suhu 30-50ºC dan inaktif pada suhu 80ºC, enzim pektinesterase isolat AR 4 dan KK 2 stabil pada suhu 30-60ºC dan inaktif pada suhu 90ºC, sedangkan enzim pektinesterase isolat AR 6 stabil pada suhu 30-60ºC namun belum inaktif pada suhu 90ºC. Nilai konstanta Michaelis-Menten (KM) enzim pektinesterase isolat AR 2, AR 4, AR 6, dan KK 2 berturut-turut adalah 0,604; 0,338; 0,971; dan 0,392 mg/ml. Sedangkan nilai kecepatan maksimum (Vmaks) enzim pektinesterase isolat AR 2, AR 4, AR6, dan KK 2 berturut-turut adalah 1,218; 0,826; 0,969; dan 1,080 U/ml. Enzim pektinesterase isolat KK 2 memiliki karakteristik yang paling sesuai untuk aplikasi dalam klarifikasi sari buah jeruk keprok garut dibandingkan dengan enzim pektinesterase isolat lainnya.Kata kunci: Enzim, klarifikasi, pektin, pektinesterase, jeruk keprok garut

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.

Determination of the Thermal Stability of Explosives

2021 ◽  
Vol 15 (2) ◽  
pp. 271-277
Author(s):  
G. M. Nazin ◽  
B. L. Korsunskiy
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of

Biochemical Discrimination of Hurler and Scheie Syndromes

1979 ◽  
Vol 57 (3) ◽  
pp. 265-272 ◽  
Author(s):  
J. J. Hopwood ◽  
Vivienne Muller
Keyword(s):  
Thermal Stability ◽  
Skin Fibroblasts ◽  
Ph Optimum ◽  
Biochemical Evidence ◽  
Cultured Skin ◽  
Thermal Stability Of ◽  
Normal Controls

1. Homogenates of cultured skin fibroblasts derived from patients with α-l-iduronidase-deficiency disorders (Hurler and Scheie syndromes) were capable of hydrolysing iduronosyl anhydro-[l-3H]mannitol 6-sulphate although at considerably reduced rates compared with normal controls. 2. The Vmax. values of α-l-iduronidase from patients with Hurler or Scheie syndromes and from normal controls were 11, 12 and 833 pmol min−1 mg−1 of protein respectively; the corresponding apparent Km values were 656, 50 and 53 μmol/l respectively. The α-l-iduronidases from normal and Scheie fibroblast homogenates were shown to exhibit pH optima at 3·6 and 4·1 and were competitively inhibited by both chloride and sulphate ions: Hurler α-l-iduronidase activity exhibited one pH optimum at 3·8 and was also inhibited by chloride and to a lesser extent by sulphate ions. 3. The thermal stability of Hurler, Scheie and normal α-l-iduronidase activities at 55°C gave half-lives of approximately 1·0, 2·5 and 1·0 h respectively. 4. These biochemical findings clearly demonstrate enzyme differences for these two clinically distinct phenotypes and provide biochemical evidence that the Hurler and Scheie syndromes result from different allelic mutations.

Isolation and Partial Characterization of Alcohol Dehydrogenase From Broad Bean (Vicia faba)

1974 ◽  
Vol 1 (4) ◽  
pp. 579 ◽  
Author(s):  
S Leblova
Keyword(s):  
Thermal Stability ◽  
Alcohol Dehydrogenase ◽  
Broad Bean ◽  
Plant Tissues ◽  
Growth Substances ◽  
Ph Optimum ◽  
Alcohol Dehydrogenase Activity ◽  
Km Value ◽  
Thermal Stability Of

Alcohol dehydrogenase isolated from broad bean was found to have a Km value of 1.0 × 1.0 -2 M, a pH optimum of 8.7 and a molecular weight of 60 000 � 5000. The enzyme lost 55 % of its activity after being heated at 55�C, and was totally inactivated at 70°C. Thermal stability of the enzyme was not enhanced by NAD+ or ethanol. The substrate specificity of the enzyme is reported. Cysteine and mercaptoethanol activated the enzyme, whilep-chloromercuribenzoate, Cu2+, Hg2+, B4O72- -, Zn2+ and EDTA inhibited it. The influence of ethanol, acetaldehyde and growth substances on alcohol dehydrogenase activity in germinating broad bean seeds and plant tissues was also studied.

Rat liver L-threonine deaminase: Properties and purification

1985 ◽  
Vol 5 (6) ◽  
pp. 499-508 ◽  
Author(s):  
R. Leoncini ◽  
R. Pagani ◽  
A. Casella ◽  
E. Marinello
Keyword(s):  
Thermal Stability ◽  
Rat Liver ◽  
Competitive Inhibitor ◽  
New Method ◽  
Optimum Temperature ◽  
Temperature Optimum ◽  
Threonine Deaminase ◽  
Ph Optimum ◽  
Carbonate Ions

A new method of purification of rat liver L-threonine deaminase has been developed, and the results obtained are compared with values obtained by other authors. Some properties of this enzyme (pH optimum, temperature optimum, thermal stability, specificity, etc.) have been examined and we found that the enzyme is inhibited by carbonate ions, that L-cysteine (a competitive inhibitor) is also an inactivator of the enzyme and that it is bound to the enzyme in a ratio of 0.25 mole of cysteine per mole of enzyme, supporting the hypothesis that the enzyme consists of 4 subunits.

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