The analysis of the results by single type of mild stress (first analysis) as well as the analysis of the interactions (second analysis) indicates that the exposure to the OCC did not have a negative effect on the viability of Leuconostoc mesenteroides. In all the analysis performed by single type of mild stress (fist analysis) the same pattern was found; there were no significant differences between the negative and positive controls, low and medium levels of stress-agent within a given type of mild stress except for the highest levels of stress-agents which were significantly detrimental. In acid mild stress the survivability of Leuconostoc mesenteroides ranged from 103-63% the highest being the positive control and the lowest being exposure to pH 4.0 (Figure 4.1). Figure 4.2 shows that with the heat mild treatment no significant differences were found among both controls and all levels of mild heat stress (P > 0.05). The survivability ranged from 105- 100% (Figure 4.2). With ethanol, the survivability of Leuconostoc mesenteroides in the OCC was only different when exposed to 15% ethanol (v/v) (P < 0.05). The highest viability was obtained with the positive control which was 106% and the lowest with the 15% ethanol (v/v) with was 62%. (Figure 4.3). With the prior exposure to the oxidative stress, the viability in the OCC raged from 106-80% the highest being the positive control and the lowest being the 7.5 mM concentration of hydrogen peroxide which …show more content…
That table shows that the time of exposure to the OCC was not significant (P > 0.05). However, the type of mild stress and levels of mild stress were significant. Therefore, the changes in viability observed caused entirely by those 2 main effects and not by the time of exposure OCC (Table
The development of A. salina will be unfavorable if exposed to too much ethyl alcohol. Treatment two and three have more ethanol alcohol than treatment one and more brine shrimp died when put into more ethanol alcohol. Since the viability was less than the viability in treatment one, the hypothesis was supported. Treatment four was the constant and had no ethanol alcohol which less cysts died when compared to treatment two and three, but when compared to treatment one, more had died,
To perform this test, a tube of broth rich with glucose is acquired. In this tube is phenol red, a pH indicator. Initially, the tube appeared pink in color, indicating a normal pH level. Next, a sample of unknown #44 is introduced into this medium using the aseptic technique, and this is allowed to sit for several days. If the organism is able to ferment glucose, the pH in the medium would decrease and cause the phenol red to exhibit a yellow color. In addition to the straw color, gas can also be produced and trapped inside the Durham tube placed in the medium. This production of acid and gas is a direct result of the fermentation of glucose, as seen with unknown
The purpose of this report is to find out the effect of change in the Temperature, PH, boiling, concentration in peroxidase activity. Peroxidase is an enzyme that converts toxic hydrogen peroxide (H2O2) into water and another harmless compound. In this experiment we use, turnips and horseradish roots which are rich in the peroxidase to study the activity of this enzyme. The activity of peroxidase with change in temperature was highest at 320 Celsius and lowest at 40C. The activity of peroxidase was highest at a pH of 7, while it was lowest at pH of 9.Peroxidase activity was very low and constant with boiled extract, while the activity was moderate
The purpose of this experiment is to learn the effects of a certain enzyme (Peroxidase) concentration, to figure out the temperature and pH effects on Peroxidase activity and the effect of an inhibitor. The procedure includes using pH5, H202, Enzyme Extract, and Guaiacol and calibrating a spectrophotometer to determine the effect of enzyme concentration. As the experiment continues, the same reagents are used with the spectrophotometer to determine the temperature and pH effects on Peroxidase activity. Lastly, to determine the effect of an inhibitor on Peroxidase, an inhibitor is added to the extract. It was found that an increase in enzyme concentration also caused an increase in the reaction rate. The reaction rate of peroxidase increases at 40oC. Peroxidase performed the best under pH5 and declined as it became more basic. The inhibitor (Hydroxy-lamine) caused a decline in the reaction rate. The significance of this experiment is to find the optimal living conditions for Peroxidase. This enzyme is vital because it gets rid of hydrogen peroxide, which is toxic to living environments.
The results in (Table 29, Fig. 31) illustrated that as temperature of heating and time of exposure of the enzyme increase, stability of this enzyme decrease. The purified pectinase enzyme when exposed to 45°C
In part II of the lab six small glass tubes were obtained in a test tube rack. Ten drops of distilled water were then added to test tube 1, five drops to tubes 2-4, and no drops in tubes 5 and 6. Five drops of 0.1M HCl were added to test tube 5 and five drops of 0.1M NaOH to test tube 6. Five drops of enzyme were then added to all tubes except tube 1. Tube 3 was then placed in the ice bucket and tube 4 was placed in the hot bucket at 80-900C for five minutes, the remaining tubes were left in the test tube rack. After the five minutes five drops of 1% starch was added to every tube and left to sit for ten minutes. After ten minutes five drops of DNSA were then added to all the tubes. All the tubes were then taken and placed in the
This experiment was centered on metabolic and biochemical testing procedures. The rationale of performing these tests was to distinguish six different microbes from one another and to compare how their metabolic and biochemical processes differ from species to species to determine the unknown sample.
The purpose of this experiment was to test the effects that temperature, pH, and substrate
This experiment is designed to analyze how the enzyme catalase activity is affected by the pH levels. The experiment has also been designed to outline all of the directions and the ways by which the observation can be made clearly and accurately. Yeast, will be used as the enzyme and hydrogen peroxide will be used as a substrate. This experiment will be used to determine the effects of the concentration of the hydrogen peroxide versus the rate of reaction of the enzyme catalase.
Procedure: Obtained a small Styrofoam cooler placed two small light bulbs in side and observed temperature over 24 hours to ensure temperature could be maintained between 98-100 degrees. Using a 10% bleach solution I then cleaned my work area. Transferring one capsule of L. acidopholis into a tube of MRS broth using the aseptic transfer technique then marked a line on test tube to record sediment. Labeled tube of nutrient broth S. epidermidis, then using a sterile swab obtained sample of
The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.
Whole natural foods that have been processed, had things added to, or taken away from them and/or heated to high temperatures actually end up being severely damaged. These processes cause the food to chemically change form with the direct result leaving that food with very little of the goodness it originally contained.
Strongyloides stercoralis is a nematode that infects approximately 100 million humans worldwide each year. Infection is endemic in tropical regions.
If different trials last longer or shorter than others, the measure of oxygen may differ from other trials.
The purpose of this experiment was to determine the effects that temperature has on three different organisms. Temperature is one of the most important environmental factors affecting growth and survival of microorganisms². The three organisms used where Escherichia coli, Pseudomonas fluorescens, and Bacillus stearothermophilis. Most bacteria grow within a particular temperature range. The minimum growth temperature is the lowest temperature at which a bacterium can still grow, while the maximum growth temperature is the highest temperature at which a particular bacterium can still grow. The optimum growth temperature is the temperature at which the bacterium