scholarly journals Preparation of immobilized baker's-yeast glucose 6-phosphate dehydrogenase attached to modified sepharose and sephadex and a comparison of the properties of these preparations with those of the soluble enzyme

1976 ◽  
Vol 157 (2) ◽  
pp. 289-294 ◽  
Author(s):  
M A Goheer ◽  
B J Gould ◽  
D V Parke
Keyword(s):  
Immobilized Enzyme ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Soluble Enzyme ◽  
Ph Optimum ◽  
Yeast Saccharomyces Cerevisiae ◽  
Enzyme Preparations ◽  
Ph Range ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Sepharose 4B

1. Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate-NADP+ oxidoreductase, EC 1.1.1.49) from baker's yeast (Saccharomyces cerevisiae) was immobilized on CNBr-activated Sepharose 4B with retention of about 3% of enzyme activity. This uncharged preparation was stable for up to 4 months when stored in borate buffer, pH7.6, at 4 degrees C. 2. Stable enzyme preparations with negative or positive overall charge were made by adding valine or ethylenediamine to the CNBr-activated Sepharose 4B 30min after addition of the enzyme. 3. These three immobilized enzyme preparations retained 40-60% of their activity after 15 min at 50 degrees C. The soluble enzyme is inactivated by these conditions. 4. The soluble enzyme lost 45 and 100% of its activity on incubation for 3h at pH6 and 10 respectively. The three immobilized-enzyme preparations were completely stable over this entire pH range. 5. The pH optimum of the positively and negatively charged immobilized-enzyme preparations were about 8 and 9 respectively. The soluble enzyme and the uncharged immobilized enzyme had an optimum pH at about 8.5 6. Glucose 6-phosphate dehydrogenase immobilized on CNBr-activated Sephadex G-25 was unstable, as was enzyme attached to CNBr-activated Sepharose 4B to which glycine, asparitic acid, valine or ethylenediamine was added at the same time as the enzyme.

scholarly journals Kinetic mechanism from steady-state kinetics of the reaction catalysed by baker's-yeast glucose 6-phosphate dehydrogenase in solution and covalently attached to sepharose

1976 ◽  
Vol 157 (2) ◽  
pp. 389-393 ◽  
Author(s):  
B J Gould ◽  
M A Goheer
Keyword(s):  
Immobilized Enzyme ◽  
Packed Bed ◽  
Kinetic Mechanism ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Soluble Enzyme ◽  
Steady State Kinetics ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Sepharose 4B ◽  
Kinetics Of

1. The reaction catalysed by glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate-NADP+ oxidoreductase, EC 1.1.1.49) from baker's yeast was studied in 42mM-glycylglycine buffer, pH7.4 at 25 degrees C, by initial-velocity studies and by the use of NADPH as a product inhibitor. 2. The reactions catalysed by both the soluble enzyme and a stable enzyme covalently attached to CNBr-activated Sepharose 4B probably follow an ordered reaction mechanism with NADP+ and NADPH as the leading reactants. 3. The kinetic constants obtained for the soluble enzyme lere: KNADP+m, 19 muM; KNADP+s, 23 muM; KNADPHs, 15 muM. Similar values were obtained for the immobilized enzyme. 4. The assay of the immobilized enzyme was done by using a micro packed-bed recirculation reactor, and the advantages of this technique are discussed.

The use of β-glucan extracted from baker’s yeast (Saccharomyces cerevisiae) to increase non-specific immune system and resistence of tilapia (Oreochromis niloticus) to Aeromonas hydrophila

2013 ◽  
pp. 92
Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Immune System ◽  
Aeromonas Hydrophila ◽  
Phagocytic Activity ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Randomized Design ◽  
The Difference ◽  
Motile Aeromonas Septicaemia

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©

scholarly journals Improving Industrial Full-Scale Production of Baker's Yeast by Optimizing Aeration Control

2008 ◽  
Vol 91 (3) ◽  
pp. 607-613 ◽  
Author(s):  
Carlos A Blanco ◽  
Julia Rayo ◽  
José M Giralda
Keyword(s):  
Dissolved Oxygen ◽  
Baker’S Yeast ◽  
Scale Production ◽  
Baker's Yeast ◽  
Fed Batch ◽  
Concentration Data ◽  
Metabolite Formation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Lineal Regression ◽  
Yeast Concentration

Abstract This work analyzes the control of optimum dissolved oxygen of an industrial fed-batch procedure in which baker's yeast (Saccharomyces cerevisiae) is grown under aerobic conditions. Sugar oxidative metabolism was controlled by monitoring aeration, molasses flows, and yeast concentration in the propagator along the later stage of the propagation, and keeping pH and temperature under controlled conditions. A large number of fed-batch growth experiments were performed in the tank for a period of 16 h, for each of the 3 manufactured commercial products. For optimization and control of cultivations, the growth and metabolite formation were quantified through measurement of specific growth and ethanol concentration. Data were adjusted to a model of multiple lineal regression, and correlations representing dissolved oxygen as a function of aeration, molasses, yeast concentration in the broth, temperature, and pH were obtained. The actual influence of each variable was consistent with the mathematical model, further justified by significant levels of each variable, and optimum aeration profile during the yeast propagation was found.

scholarly journals Evaluation of the Fermentation Dynamics of Commercial Baker’s Yeast in Presence of Pistachio Powder to Produce Lysine-Enriched Breads

Fermentation ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 2 ◽  
Author(s):  
Antonio Alfonzo ◽  
Raimondo Gaglio ◽  
Marcella Barbera ◽  
Nicola Francesca ◽  
Giancarlo Moschetti ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Density ◽  
Titratable Acidity ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Promising Strategy ◽  
Total Titratable Acidity ◽  
Bread Production ◽  
Kinetics Of

The present work was carried out to evaluate the microbiological, physicochemical, and sensory characteristics of fortified pistachio breads. Pistachio powder (5% w/w) was added to flour or semolina and fermented by a commercial baker’s yeast (Saccharomyces cerevisiae). Pistachio powder did not influence the biological leavening of the doughs. The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that the leavening process occurred similarly for all trials. The concentration of yeasts increased during fermentation and reached levels of 108 CFU/g after 2 h. Pistachio powder decreased the height and softness of the final breads and increased cell density of the central slices. The amount of lysine after baking increased in pistachio breads and this effect was stronger for semolina rather than flour trials. Sensory evaluation indicated that fortified breads processed from semolina were those more appreciated by the judges. This work clearly indicated that the addition of pistachio powder in bread production represents a promising strategy to increase the availability of lysine in cereal-based fermented products.

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