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

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.

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.

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 Isolasi, Pemurnian dan Karakterisasi Fitase Bacillus subtilis dari Holiwood Gresik

2010 ◽  
Vol 15 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Leny Yuanita ◽  
Aline Puspita ◽  
Suzana Surodjo ◽  
Sri Hidayati ◽  
Farid Al Amin ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Gel Filtration ◽  
Control Group ◽  
Optimum Temperature ◽  
Ph Optimum ◽  
Control Group Design ◽  
Group Design ◽  
Optimum Ph ◽  
Post Test ◽  
Km Value

The aim of the research were isolation, purification and characterization of Bacillus subtilis phytase from Holiwood Gresik. The research was done in two stages; the first include enzyme isolation, precipitation with amonium sulphate, dialysis, gel filtration chromatography, SDS-PAGE analysis, while second determining optimum pH, optimum temperature, the effect of pH and temperature to enzim stability, the values of KM and Vmax Bacillus subtilis phytase from Holiwood Gresik. The first stage research design were One Shot Case Study and Post Test Only Control Group Design, while the second stage were Post Test Only Control Group Design and Factorial Design. The data being analyzed by one-way and two-way Anova. The results of research showed that Bacillus subtilis phytase has the molecular mass of 36.5 kDa, optimum pH at 6.5–7.0, optimum temperature at 41° C and it was found to be stable for 30 minute incubation at pH 7 or 30° C with 2% or 3% lost of its activity respectively. KM value was 0.62 mM and VMax 0.393 mmol/ml/minute.

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 Characterization of Biosynthetic Enzymes for Ectoine as a Compatible Solute in a Moderately Halophilic Eubacterium, Halomonas elongata

1999 ◽  
Vol 181 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hisayo Ono ◽  
Kazuhisa Sawada ◽  
Nonpanga Khunajakr ◽  
Tao Tao ◽  
Mihoko Yamamoto ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Apparent Molecular Mass ◽  
Optimum Temperature ◽  
Sds Page ◽  
Halomonas Elongata ◽  
Optimum Ph

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.

Characterization of Hexokinase and Fructokinase from Suspension-Cultured Catharanthus roseus Cells

1988 ◽  
Vol 43 (11-12) ◽  
pp. 827-834 ◽  
Author(s):  
Yüko Yamashita ◽  
Hiroshi Ashihara
Keyword(s):  
Catharanthus Roseus ◽  
Divalent Cations ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Phosphate Donor

Abstract Two different hexose-phosphorylating enzymes, hexokinase and fructokinase, were partially purified from suspension-cultured Catharanthus roseus cells. One of the enzymes, hexokinase, catalyzed the phosphorylation of both glucose and fructose. The Km values for glucose and fructose were 0.06 mM and 0.23 mM, respectively. The Vmax of the enzyme with fructose was approximately three times higher than with glucose. This enzyme was specific in its requirement for ATP and its Km value for ATP was 52 μM. The optimum pH was 8.0 and Mg2+ or Mn2+ was required for the activity. The activity was inhibited by considerably higher concentrations of ADP (i.e., 4 mM ADP was required for 50% inhibition). The second enzyme, fructokinase, was specific for fructose, and no activity was detected with glucose as substrate. This enzyme used UTP or CTP as phosphate donor. The Km values of this enzyme for fructose and UTP were 0.13 mM and 0.15 mM, respectively. The pH optimum was 7.2, and Mg2+ or Mn2+ was required for the activity. These divalent cations could be partially replaced by Ca2+. The activity was inhibited noncompetitively by ADP and AMP. 90% inhibition of the activity by 0.5 mM ADP was observed in the presence of 2 mM UTP and 5 mM MgCl2. Fructose-2,6-bisphosphate, glucose-1,6-bisphosphate, glucose-6-phosphate, and fructose-6-phosphate had little or no effect on the activity of both the hexokinase and the fructokinase. Based on these results, a discussion is presented of the role of hexokinase and fructokinase and their involvement in the regulation of the metabolism of sugars in Catharanthus cells.

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.

Regulation of acetyl-CoA carboxylase by glucagon in HeLa cells

1985 ◽  
Vol 5 (6) ◽  
pp. 491-497
Author(s):  
R. P. Bhullar ◽  
K. Dakshinamurti
Keyword(s):  
Thermal Stability ◽  
Rat Liver ◽  
Hela Cells ◽  
Competitive Inhibitor ◽  
Acetyl Coa Carboxylase ◽  
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.

scholarly journals Purification and characterization of endoglucanase Ss from Clostridium thermocellum

1991 ◽  
Vol 279 (1) ◽  
pp. 67-73 ◽  
Author(s):  
U Fauth ◽  
M P M Romaniec ◽  
T Kobayashi ◽  
A L Demain
Keyword(s):  
Clostridium Thermocellum ◽  
Hydrophobic Interaction Chromatography ◽  
Cellulolytic Enzymes ◽  
Crystalline Cellulose ◽  
Optimum Temperature ◽  
Purification And Characterization ◽  
Specific Antibodies ◽  
Optimum Ph ◽  
Exchange Adsorption

The extracellular cellulolytic enzymes of the thermophilic anaerobe Clostridium thermocellum occur as a protein complex or aggregate known as the cellulosome. By using a combination of ion-exchange, adsorption and hydrophobic-interaction chromatography, it was possible to isolate from extracellular broth a specific endoglucanase of interest without the use of denaturants. The endoglucanase was identified as the cellulosomal subunit Ss by the use of specific antibodies. The enzyme has an Mr of 83,000, an isoelectric point of 3.55, optimum pH of 6.6 and optimum temperature of 70 degrees C. It hydrolyses CM-cellulose and, at a higher rate, the cellodextrins, cellotetraose and cellopentaose, but does not hydrolyse a crystalline cellulose such as Avicel. Cellobiose and cellotriose are also immune to attack. It differs from endoglucanases previously isolated by others and a 76,000-Mr endoglucanase recently isolated in this laboratory.

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