The first experiment conducted tested the effect different concentrations had on the bacteria Bacillus Subtilis. An agar plate was separated into four sections which contained: 100% Dettol, 50% Dettol, 25% Dettol and distilled water. It was hypothesised that the 100%, 50% and 25% Dettol would kill the most to least bacteria respectively and that the distilled water would not kill any bacteria. The hypothesis was mainly accurate however there was a small contradiction. The 100% Dettol killed the most bacteria with a kill zone covering 75% of its designated section and only 30 colonies remaining when examining the plates. The 50% Dettol was the second most successful at killing the Bacillus Subtilis. 50% of bacteria in the section were killed
Data table 1 Well plate Contents Glucose concentration A 3 drops 5% sucrose + 3 drops distilled water Negative B 3 drops milk+3 drops distilled water Negative C 3 drops 5% sucrose +3 drops lactase Negative D 3 drops milk +3 drops lactase 15+ E 3 drops 20% glucose +3 drops distilled water 110 ++ Questions B. In this exercise, five reactions were performed. Of those reactions, two were negative controls and one was a positive control.
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
In this lab project, the microbiology students were given 2 unknown bacteria in a mixed broth each broth being numbered. The goal of this project is to determine the species of bacteria in the broth. They had to separate and isolate the bacteria from the mixed broth and ran numerous tests to identify the unknown bacteria. The significance of identifying an unknown bacteria is in a clinical setting. Determining the exact bacteria in order to prescribe the right treatment for the patient. This project is significant for a microbiology students because it gives necessary skills to them for future careers relating to clinical and research work.
After the end of the experiment the unknown 10 sample was Staphylococcus epidermidis. Came to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester it was determined that the blood agar, MSA, and catalase test are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria. The results of the gram stain test were cocci and purple. This indicated that the unknown bacteria were gram positive. The gram stain test eliminated Escherichia coli, Klebsiella pneumonia, Salmonella enterica, and Yersinia enterocolitica as choices because these bacteria are gram negative. Next a Blood Agar plate was used because in order to do a MSA or a Catalase test there needs to be a colony of the bacteria. The result of the Blood Agar plate was nonhemolytic. This indicated that there was no lysis of red blood cells. By looking at the plate there was no change in the medium. Next an MSA test was done and the results showed that there was growth but no color change. This illustrates that the unkown bacteria could tolerate high salt concentration but not ferment mannitol. The MSA plate eliminated Streptococcus pneumonia and Streptococcus pyogenes as choices since the bacteria can’t grow in high salt concentration. Staphylococcus aureus could be eliminated because not only did the unknown bacteria grow but also it didn’t change color to yellow. Lastly a Catalase test was done by taking a colony from the Blood Agar plate...
One of the most primitive actions known is the consumption of lactose, (milk), from the mother after birth. Mammals have an innate predisposition towards this consumption, as it is their main source of energy. Most mammals lose the ability to digest lactose shortly after their birth. The ability to digest lactose is determined by the presence of an enzyme called lactase, which is found in the lining of the small intestine. An enzyme is a small molecule or group of molecules that act as a catalyst (catalyst being defined as a molecule that binds to the original reactant and lowers the amount of energy needed to break apart the original molecule to obtain energy) in breaking apart the lactose molecule. In mammals, the lactase enzyme is present
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
What do bacteria need to grow? For bacteria to grow the most typical thing that they like ate a warm and moist environment, but that is not all that they like. Bacteria also like and environment with a PH that is normal or close to a human PH and bacteria also like an oxygen rich environment. The places that could be common to find bacteria in a building are a keyboard, a water fountain, and restrooms. A keyboard is a common place for bacteria because it is being touched constantly with hands when people type and hands are warm, so bacteria like them. The water fountain is another place that is common for bacteria to grow because people's warm hands are touching it and also it has water, which causes it to be moist. The last place that bacteria will we commonly found in buildings are restrooms. The bacteria like restrooms because many people are in then and also there is a lot of water in them.
Using the new bacteria acclimated to DDT, fields where DDT was once applied can now be cleaned more thoroughly. The acclimated bacteria will still carry out their natural life functions, but now the metabolic processes of the Serratia Marcescens are now more capable of using the DDT as an energy source, and, therefore, the microbes will degrade the DDT faster.
Madar, Sylvia S., & Windelspecht, Michael. (2014). Inquiry into Life, Metabolism: Energy & Enzymes (pp. 104-107). New York: McGraw Hill.
In 5 petri dishes used pipettes to gather 20 live brine shrimp and place in each dish. Labeled each petri dish accordingly and then observed the live brine shrimp in their controlled environment for 5 minutes. After the 5 minutes I counted the number of live brine shrimp and recorded the information. Hypothesis is that 20% concentration of ammonia will kill off 50% of the brine shrimp.
There were five test solutions used in this experiment, water being the control, which were mixed with a yeast solution to cause fermentation. A 1ml pipetman was used to measure 1 ml of each of the test solutions and placed them in separated test tubes. The 1 ml pipetman was then used to take 1ml of the yeast solution, and placed 1ml of yeast into the five test tubes all containing 1 ml of the test solutions. A 1ml graduated pipette was placed separately in each of the test tubes and extracted 1ml of the solutions into it. Once the mixture was in the pipette, someone from the group placed a piece of parafilm securely on the open end of the pipette and upon completion removed the top part of the graduated pipette.
In our Biology Lab we did a laboratory experiment on fermentation, alcohol fermentation to be exact. Alcohol fermentation is a type of fermentation that produces the alcohol ethanol and CO2. In the experiment we estimated the rate of alcohol fermentation by measuring the rate of CO2 production. Both glycolysis and fermentation consist of a series of chemical reactions, each of which is catalyzed by a specific enzyme. Two of the tables substituted some of the solution glucose for two different types of solutions. They are as followed, Table #5 substituted glucose for sucrose and Table #6 substituted the glucose for pH4. The equation for alcohol fermentation consists of 6 Carbons 12 Hydrogens 6 Oxygen to produce 2 pyruvates plus 2 ATP then finally the final reaction will be 2 CO2 plus Ethanol. In the class our controlled numbers were at Table #1; their table had 15 mL Glucose, 10 mL RO water, and 10 mL of yeast which then they placed in an incubator at 37 degrees Celsius. We each then measured our own table’s fermentation flasks every 15 mins for an hour to compare to Table #1’s controlled numbers. At
I was going looking at my final exam schedule at realized that the final exam for Introduction to Food Science was thirty minutes after my final exam for Introductory Microbiology. Is there anyway I could possibly take your final at a different time?
organism in the samples. The filtration isolation technique and the treatment methods used to eliminate other microorganisms in the water have an effect in the reduction of few viable Legionella that may be present in the samples. The concentration of the water sample using filtration increased the sensitivity of the method, but not the specificity. According to several studies, filtration brings about a reduction in detectable Legionellae of 16-91% (Brindle et al., 1987; Boulanger and Edelstein, 1995; Ta et al., 1995). While the decontamination with acid buffer and heat, which increased the specificity to Legionella, lead to a decrease in isolated Legionellae between 5 and 99% (Boulanger and Edelstein, 1995; Roberts et al., 1987). The samples may possibly harbor the organism, but the process of filtration and treatment performed may have killed the