Microbial Survey, Smear Preparation, and Simple Stain Essay

Yeasts are unicellular organisms belonging to the fungi kingdom and Eukarya Domain. Yeast are heterotrophs which gain its energy from enzymes that break down carbohydrates into alcohol and CO2. It can also derive energy from simple sugars such as fructose and glucose, which can be found mostly in groups and reproduce asexually (occasionally sexually). Asexual yeast reproduction is accomplished through a process called budding. Budding occurs when a yeast cell achieves full growth. It then sprouts a bud like swelling on its surface. Part of the parent cell’s nucleus is taken and put into this bud, which then is encased by a wall. The

To perform this test, a small drop of water is placed on a clean microscope slide. A metal loop that has been properly sterilized in the blue flame and allowed time to cool is used to

1) Apply the stain to your first unknown slide and examine it under the microscope.

Read in your lab manual about the following agar mediums: Blood Agar (pg 168), EMB Agar (pg 170), Mannitol Salt Agar (MSA)(pg 172) ), MacConkey Agar (pg 174), and PEA Agar (pg 176) to answer the following:

Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

Today in medicine doctors are rapidly isolating and distinguishing the many pathogenic microbes encountered daily within the environment. Public health has been affected from the faster identification of microorganisms by delivering an accurate analysis to patients in order to receive treatment of the disease in a timely manner. Due to the growing understanding of these organisms more have been easier to indicate to improve water quality. Also more methods have been developed for better treatment options from fecal bacteria in public water systems. Scientist has developed such specific methods of identifying the unknown organism to tell if the contamination has come from either a human, bird, or mammal. (Achtman et al., 2008)

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

A light microscope was set up with the light on a low setting; one large Daphnia was selected and placed in the centre of a cavity slide by using a pipette.

Again, after ten seconds, the slide was rinsed with distilled water to wash off the decolorizer. The slide was placed back on the staining rack. Approximately ten drops of safranin were covered on the slide allowing resting for one minute. After one minute, the slide was rinsed one final time on the small sink followed by blotting the stained slide with Bibulous paper. The slide was placed between pages of Bibulous paper to help

A form of reproduction that requires only one parent and disallows genetic diversity between parent and daughter, as both share the same DNA. It is used for regenerating lost cells, and growth.

The Latin word for mushroom is fungus (plural, fungi). The word fungus has come to stand for a whole group of simple plants that contain no chlorophyll and lack such complex plant structures as roots, stems, leaves, and flowers. Included among the fungi, along with mushrooms, are molds, mildews, rusts, smuts, truffles, and yeasts. Toadstool is another name for mushroom. Some people use the name toadstool only when referring to poisonous mushrooms, but botanists make no such distinction. A general scientific term for fungi is mycota, from the Greek word for mushroom, mykes, and the study of these organisms is called mycology.

The materials used for the first part of the experiment comprised of the following: a microscope, 4 slides, 4 slide covers, blood samples, lancet, a sheet of paper towel, 3 test tube droppers, Solutions A, Solutions B, and Solution C.

Procedure: First, set up the microscope. Clean the ocular lenses and objectives with lens paper. Then pace the prepared e slide on the stage and make adjustments. Turn the rotating nosepiece until the 10x objective is above the ring of light coming through the slide. Move the slide using the X and Y stage knobs until the specimen is within the view. Adjust the focus by looking into the eyepiece and focusing the specimen with the coarse then fine focus knobs. Adjust diaphragm until there is sufficient light

Introduction: Through the conduction of numerous experiments, the identity of two bacterial isolates was determined. The tested specimen was an unknown sample of a mixed culture of two different species of bacteria. The first step that was taken was obtaining a pure culture of each species of bacteria by isolating one species from the other. Once isolation was complete, the isolated cultures were tested using procedures that had been performed during previous lab sessions. A gram stain was performed on the two isolates. The isolate which had tested gram negative was then tested for the presence of cytochrome C and lactose fermentation. For the gram positive isolate, cell shape was determined and a catalase test was performed.

This report represents my individual effort. I did not receive or offer aid to anyone when performing this assignment, nor did I plagiarize any material.