T. Kolusheva, A. Marinova Journal of the University of Chemical Technology and Metallurgy, 42, 1, 2007, 93-96 A STUDY OF THE OPTIMAL CONDITIONS FOR STARCH HYDROLYSIS THROUGH THERMOSTABLE α - AMYLASE T. Kolusheva, A. Marinova University of Chemical Technology and Metallurgy 8 Kl. Ohridski, 1756 Sofia, Bulgaria E-mail: e-mail: manahova@abv.bg. Received 10 July 2006 Accepted 12 November 2006 ABSTRACT The present work determines the optimal conditions for starch hydrolysis by thermostable α -amylase (EC 3.2.1.1) produced by Bac.subtilis strain XÊ-86. The hydrolysis reaction has the greatest rate at pH = 7.0, starch substrate concentration 250 g.l-1, enzyme concentration 12 enzyme units per ml suspension and 90o C temperature. We …show more content…
The amount of the reducing sugars like glucose or inverted sugar contained in the sample is calculated from the quantity of the Cu2+ from the Fehling solution which have undergone a reaction with the sugar, by using the Bertrand tables [4]. RESULTS AND DISCUSSION To study the optimal conditions for the hydrolysis of starch with the a amylase enzyme XK 60 under consideration, we have varied the following factors: concentration of the substrate, concentration of the enzyme, temperature of the hydrolysis, pH and the influence of inhibitors. In order to determine the optimal concentration of the substrate we have done experiments in the range from 100 to 300 g.l-1 starch. From the results presented in Table 1 it is evident that for substrate concentrations 250 and 300 g.l-1, the level of hydrolysis is almost the same (30.1 % and 30.3 % respectively). We supposed that this was most likely due to the inhibiting action of the reducing sugars obtained during hydrolysis at substrate concentrations higher than 250 g.l-1. To prove this hypothesis, we investigated the influence of the concentration of the glucose added to the substrate on the rate of the enzymatic reaction. As can be seen from Fig. 1, the addition of glucose in the beginning of the hydrolysis process significantly reduces the reaction rate of the process. The
1) Amylase is utilized to break down starch molecules into more simple sugars for use by the body. It performs this function by hydrolyzing glycosidic linkages in the polysaccharide chain.
During these experimental procedures, the implication of multiple different temperatures on fungal and bacterial amylase was studied. In order to conduct this experiment, there were four different temperatures used. The four temperatures used were the following: 0 degrees Celsius, 25 degrees Celsius, 55 degrees Celsius, and 80 degrees Celsius - Each temperature for one fungal and one bacterial amylase. Drops of iodine were then placed in order to measure the effectiveness of the enzyme. This method is produced as the starch test. The enzyme was tested over the course of ten minutes to determine if starch hydrolysis stemmed. An effective enzyme would indicate a color variation between blue/black to a more yellowish color towards the end of the time intervals, whereas a not so effective enzyme would produce little to no change in color variation. According to the experiment, both the fungal amylase and bacterial amylase exhibited a optimal temperature. This was discovered by observing during which temperature and time period produced a yellow-like color the quickest. Amylase shared a similar optimal temperature of 55 degrees Celsius. Most of the amylases underwent changes at different points, but some enzymes displayed no effectiveness at all. Both amylases displayed this inactivity at 0 degrees Celsius. At 80 Celsius both the enzymes became denatured due to the high temperatures. In culmination, both fungal and bacterial amylase presented a array of change during it’s
Hydrolysis of starch for fungal amylase Aspergillus Oryzae and bacterial amylase Bacillus Licheniformis at different temperatures.
Effect of varying Temperatures on Enzymatic Activity of Bacterial and Fungal Amylase and hydrolysis of Starch
Enzymes react differently under different conditions and concentrations, being the most productive at the enzymes specific optimum condition and concentration. The enzyme sucrase, extracted from yeast, breaks down the complex sugar sucrose into the simple sugar glucose. Testing for sucrase’s optimum environment, multiple reactions were ran using varying amounts and concentrations of sucrose and sucrase at different pHs and temperatures. The product was then treated with Benedicts solution to visually observe what amount of glucose was present after the reaction was ran; negative results being little to no glucose present and positive results being
Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.
The effects of temperature on fungal amylase Aspergillus oryzae, and bacterial amylase, Bacillus licheniformis ability to break down starch into maltose was studied. The study determined the optimal temperature the Aspergillus oryzae and Bacillus licheniformis was able to break down the fastest. The starch catalysis was monitored by an Iodine test, a substance that turns blue-black in the presence of starch. Amylase catabolizes starch polymers into smaller subunits. Most organisms use the saccharide as a food source and to store energy (Lab Manual, 51). The test tubes were labeled with a different temperature (0°C, 25°C, 55°C, 85°C). Each test tube was placed in its respective water baths for five minutes. After the equilibration process, starch was placed in the first row of the first row of the spot plate. Iodine was then added to the row revealing a blue black color. The starch was then added to the amylase. After every two minute section a pipette was used to transfer the starch-amylase solution to place three drops of the solution into the spot plate row under the corresponding temperature. Iodine drops was placed in the row. Color changes were noted and recorded. The results showed Aspergillus oryzae was found to have an optimal temperature between 25°C and 55°C and Bacillus licheniformis was found to have an
Olmsted, John III; Williams, Greg; Burk, Robert C. Chemistry, 1st Canadian ed.; John Wiley and Sons Ltd: Mississauga, Canada, 2010, pp 399 - 406
Hypothesis: If we decrease the level of pH in the enzyme Amylase, it will not be able to denature the carbohydrates in the potato starch solution after 10 drops because enzymes are very sensitive to pH levels and lowering it too much will compromise its ability to break them down.
Amylase experiment # 2 was done to see how the pH affected the efficacy of the enzyme. First we collected all of the materials that were necessary to make this experiment. We needed five clean test tubes, the following standard solutions, 1% Starch Solution pH 3,1% Starch Solution pH 5,1% Starch Solution pH 7,1% Starch Solution pH 9,1% Starch Solution pH 11
In this lab we looked at the role of pancreatic amylase in the digestion of starch and the effect that temperature and pH has on this enzyme. Enzyme’s work as catalysts that increase the rate of chemical reactions within cells (Cooper, 2000). In order to do this, enzymes must show two essential properties: these two fundamental properties of enzymes include increasing the rate of chemical reactions without being eternally altered by the reaction and accelerating the reaction rate with keeping the reactants and products in chemical equilibrium (Cooper, 2000). Enzymatic catalysis is necessary for life. Most biochemical reactions would not occur under the mild temperatures and pressures
The use of multiple test tubes and Parafilm was used for each experiment. Catechol, potato juice, pH 7 phosphate buffer, and stock potato extract 1:1 will be used to conduct the following experiments: temperature effect on enzyme activity, the effect of pH on enzyme action, the effect of enzyme concentration, and the effect of substrate concentration on enzyme activity. For the temperature effect on enzyme activity, three test tube were filled with three ml of pH 7 phosphate buffer and each test tube was labels 1.5 degrees Celsius, 20 °C, and 60 °C. The first test tube was placed in an ice-water bath, the second test tube was left at room temperature, and the third test tube was placed in approximately 60°C of warm water. After filling the test tubes with three ml of the
The purpose of this experiment was to record catalase enzyme activity with different temperatures and substrate concentrations. It was hypothesized that, until all active sites were bound, as the substrate concentration increased, the reaction rate would increase. The first experiment consisted of five different substrate concentrations, 0.8%, 0.4%, 0.2%, 0.1%, and 0% H2O2. The second experiment was completed using 0.8% substrate concentration and four different temperatures of enzymes ranging from cold to boiled. It was hypothesized that as the temperature increased, the reaction rate would increase. This would occur until the enzyme was denatured. The results from the two experiments show that the more substrate concentration,
How pH Affects the Break Down of Starch by the Enzyme Amylase Hypothesis: The optimum pH for the reaction of starch with amylase is pH 7. PH values lower or higher than this value will result in a slower rate of reaction. Amylase works in the range pH 3 to pH 11.
Amylase is an enzyme that is in human’s saliva as well as the pancreas. Enzymes are biological catalysts that speed up a chemical reaction. They break down complex molecules into simple ones. In this case, amylase converts starches (complex molecule) into simple sugars. That is why foods like potatoes for example, may taste sweet to us, because they contain starch. The optimum pH for pancreatic amylase is the pH of 7. In the experiment I have used buffer solutions with the pHs of 2.8, 4 and 6.5. I have also used iodine and starch. Normally, iodine is orange-yellow, however when you add starch to it, the solution will turn blue-black.