Purpose: To identify an unknown microorganism by performing a series of biochemical tests on a pure bacterial culture. Materials and Methods: Tests: Lactose fermentation: Fermentation makes energy available for use by microorganisms by anaerobic breakdown of carbohydrates. The product can either be an acid or gas. When it is positive, the broth will turn from red to yellow and if gas is present a bubble is formed. Sucrose fermentation: This fermentation makes energy available for use by microorganisms by anaerobic breakdown of carbohydrates. It can either be an acid or gas. When positive turns red to yellow and can have gas present which form bubbles. H2S production: H2S is a toxic gas produced by the decomposition of sulfur-containing amino acids cysteine and methionine or the reduction of inorganic sulfur compounds by enzymes of certain bacteria. If hydrogen sulfide is formed, it reacts with ferrous salts to form black metal sulfides that can be visualized …show more content…
The sucrose fermentation was a negative for acid meaning it was a red and a negative for gas. The H2S production was a negative because remained a yellow color instead of turning black. For the motility, it was also a negative the movement only stayed in the center than spreading throughout. The indole from tryptophan was also a negative because no ring appeared on the top layer on the reagent. With finding ammonia from urea, it was also negative meaning it did not change from orange to magenta. On the starch hydrolysis, there was no presence of a lighter zone around the bacteria after the iodine was added. When it came to the casein hydrolysis the organism did not have a presence of casein hydrolysis meaning there were no presence of a clear zone around the growth. The catalase was also a negative meaning it did not react to the hydrogen peroxide which would have caused bubbles to form around the
Introduction The purpose of this practical is to purify and detect lysozyme from a mixture of components. Lysozyme is a protein found in high concentration in egg whites and is found to be very useful in the pharmaceutical and food industry as it has a high anti-microbial, anti-viral and anti-parasite properties. In hens, it is said to account for 3.5% of the total protein in a hen egg white.
Although the nature of this kind experiment was unable to provide us with numerical data, our graph was constructed using the average percent of E. Coli killed for each pair of cultures. To determine these percents for each substance we used the process of elimination. We put the two petri dishes side by side and used a checklist ranging from 1-100% to narrow down the possibilities. After obtaining a small range of possible percents, we made an estimate to determine the percent. After doing this for both the of cultures for that pair we averaged the two numbers.
This energy meets the needs for growth and maintenance of internal functions. Under anaerobic condition, yeast switches to fermentation which utilizes only about 5% of the energy contained in glucose and ethanol as the end product is produced. Acetic acid bacteria convert glucose to produce gluconic acid and ethanol to produce acetic acid giving it a sour flavor. The acetic acid production in turn induces the yeasts to produce ethanol and making alcohol available to bacteria. Both ethanol and acetic acid possess antimicrobial properties and thereby act against pathogenic bacteria and prevents contamination of the tea fungus (Liu et al., 1996).
I. TITLE: Fecal Coliform Testing ; M. Zinkievich , L. Moore ; APES ; Wends. Oct 21 2015 II. INTRODUCTION:
E.coli strand C turned yellow under the conditions of distilled water, clear under 5% lactose and yellow under 5% sucrose. The E.coli strain B was slightly different from E.coli strand A and C under distilled water. Both E.coli strain A and C were negative while strain C was positive. There was a minute difference between E.coli strain C compared to strain A and B under the condition of 5% lactose.
Discussion Bacteria from the provided master stock plate were used for the gram stain test. Bacteria were then streak and grown from the master stock plate onto a working plate. After an incubation time of 24 hours at 37°C, the working plate bacteria were then used to perform the catalase and red blood cell hemolysis tests. After conducting the three tests, it was concluded that unknown #5 was Streptococcus agalactiae. Gram Stain Test
Bacteria can be found on most surfaces, especially in the school environment. According to the NSF, a singular water fountain contains 2,700,000 colony forming units of bacteria per square inch, that’s more than an average toilet. By sharing supplies and switching classes everyday, the spread of bacteria can happen rapidly. Schools are a playground full of bacteria and through testing several surfaces, the results will show which contains the most bacteria. My original question starting this lab was will the technology have more bacteria due to how much people use them?
Upon examining the structures of sugars it was hypothesised that glucose would produce CO2 faster, because of its structure. Sucrose would produce the highest amount of CO2, because it’s structure was a bit more complex, being a disaccharide (two sugars) made up of glucose and fructose, but not the faster as it may take more energy and time to break down the sugar. It was expected that lactose would produce almost no carbon dioxide as the disaccharide was complex and it was assumed that there were no enzymes in the yeast that could break down galactose. The results supported the hypothesis as the sucrose produced the most amount of CO2, the glucose produced the most CO2 in the first 2 minutes and the lactose produced 873 less bubbles than the other sugars on average.
Lastly, a glucose fermentation test was conducted, P. aeruginosa was aseptically transferred into a tube of glucose broth using an inoculating loop. The tube was then placed into an incubator at 37 degrees Celsius for 48 hours. Once the time had elapsed the tube appeared pink which indicated a negative test. With the negative result the unknown species was identified as P.
As illustrated in Figure 1 and 2, the volume of gas collected for both glucose and maltose produced similar carbon dioxide at a rapid pace of 0.5 min. The results indicate that there is no significant difference between the metabolic rate of glucose and maltose, due to its incubation time. However, the trials for lactose showed no signs of gas production. As shown in Figure 4, glucose had produced the most gas per minute with an average respiration rate of 6.4 mL/min, while lactose produced a negligible amount of gas of 2.6 mL/min, compared to maltose with an average respiration rate of 5.2 mL/min.
The Effect of Temperature on the Amount of Oxygen Consumed During Cellular Respiration of Saccharomyces Cerevisiae Purpose: To determine the temperature at which baker’s yeast (Saccharomyces cerevisiae) respires most efficiently in order to produce the best baked goods as possible when utilizing yeast. Research Question: How does temperature affect amount of oxygen used during cellular respiration of yeasts? Introduction: Respiration is process of releasing energy from organic compounds in order to produce energy.
Like aerobic respiration, this type of cellular respiration first involves glucose being broken down into two pyruvates through the process of glycolysis. However, because oxygen is unavailable, instead of the Krebs cycle and the electron transport chain occurring, fermentation occurs. While the process of fermentation in all organisms are alike, the products of fermentation are not the same. Lactic acid fermentation involves anaerobic cellular respiration in animals while alcoholic fermentation involves anaerobic cellular respiration in plants and yeast. Therefore, in animals such as humans, glucose is converted to lactic acid, usually in a dissolved form known as lactate.
Introduction Probiotic are small single celled living organisms either bacteria or yeast that are ingested to benefit health and help fight disease. A wide variety of different probiotics exists, but most are bacteria of the lactobacillus, Bifidobacterium enterococcus, or exherichin genera or are yeast of the genus saccharomyces (Willey et.al 2011). This practical will aid in determining where the commercial probiotics used by human contain live or viable cultures. Methods and materials A probiotic (tablet) was grinded to fine powder and an additional probiotic sachet was used.
In this practical, the production of yeasts for ethanol production from hexose and pentose sugars were
YEAST Yeasts are eukaryotic unicellular fungi which reproduce by budding or fission. Yeasts are very small, typically 5 to 10 microns (1 micron = 10-4 centimeters) which is around 5 times the size of most bacteria. Yeast cell membranes acts as impermeable barriers against hydrophilic molecules to prevent the mixing of the cytoplasm and external environment. Around 7.5 n thick