Ubiquity of Bacteria

Depending on what a bacteria can and cannot do, will help to correctly identify it. It is always important to start out with a purity check. To achieve that, you can inoculate an agar plate and incubate for 48 hours. Make sure you only see one type of colonies on the plate. Knowing the optimal temperature for the bacteria will also let a scientist know where to place the different types of medias he/she inoculates with the unknown bacteria. Knowing if you are working with a gram positive or gram negative bacterium, a scientist will need to perform a gram stain. This will also help to see the shape and arrangement of the bacteria. The size can be determined by doing a simple stain. The size of most bacteria ranges from .5- 10um. This specific bacteria that I was working with, was smaller than 2um. Most bacteria can grow with the presence of oxygen. A simple test like the gas pack can be performed to figure out if growth is possible without oxygen is doable. My unknown bacteria needs oxygen to grow. Throughout my study, the unknown bacteria was tested to see if it can grow in acidic conditions, however no growth occurred. Before inoculation, the substrate was a clear yellow color and in liquid state. After receiving the negative result, I kept the broth in the 37C incubator for 7 more days to confirm the negative result. Using premade slants with different types of sugars such as Mannitol, Sorbitol, Lactose, Trehalose, Maltose and Sucrose, to determine if the bacteria can metabolize glucose and if the bacteria is oxidative or fermentative. It was determined that my bacteria is strictly oxidative (needs oxygen to grow) and cannot metabolize glucose. Another test was done to confirm if the bacteria was able to utilize different carbohydrates in the presence of oxygen. I used Cellobiose, Arabinose, Adonitol, Fructose and Malonate wee tabs. Out of the 5 different types of carbohydrates, only 3 different

See Table 1 and Flow Chart 1 for results of Bacteria # 1 and Table 2 and Flow Chart 2 for results of Bacteria # 2.

6. The disks in the 0.00% solution were transferred to an agar plate held next to the blue flame using the sterilized tweezers. Excess disinfectant was removed from the disks by wiping on the side of the well of the spotting tile. When the 5 disks were positioned (refer to Figure 1 below) the lid was replaced and sticky taped down. A label was added indicating the concentration of disinfectant.

In the beginning of lab, we were advised to obtain a nutrient agar petri plate, which is used for the cultivation of microbes supporting growth of non-fastidious organisms. Since it contains many nutrients, a wide variety of bacteria and fungi can grow. Taking the plate,

2. The space under the free edge, called the HYPONYCHIUM, must be scrupulously cleaned when scrubbing for patient care.

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

The next step of the project included preparing a Gram stain to discover the cell shape, arrangement, and if the bacteria is gram positive or

Steadily adjusting the controls on the microscope the Daphnia was made visible and the heart was located through

The drops of crystal violets, approximately 15 drops, were flooded until the smear were all covered and then allowing resting for one to two minutes. After two minutes, the slide was titled over the sink and washed off, with the distilled water bottle, by aiming the stream of water above the smear. The specimen appeared blue-violet when observed with the naked eye. The drops of Gram’s iodine were applied on the slide until covered and then allowed to react for one minute or more. After the time elapsed, the slide was rinsed again with distilled water following immediate drops of Gram stain decolorizer added one drop at a time.

Since microorganisms are not visible to the eye, the essential tool in microbiology is the microscope. One of the first to use a microscope to observe microorganisms was Robert Hooke, the English biologist who observed algae and fungi in the 1660s. In the 1670s, “Anton van Leeuwenhoek, a Dutch merchant, constructed a number of simple microscopes and observed details of numerous forms of protozoa, fungi, and bacteria” (Introduction to Microscopes, n.d.). During the 1700s, microscopes were used to further explore on the microbial world, and by the late 1800s, the light microscope had been developed. “The electron microscope was developed in the 1940s, thus

Lab Day 2: The first procedure that was done was a simple stain to identify the bacterial shape. Bacteria tends to be transparent, so a stain must be use to color the cells of the bacteria so it can be viewed under a compound microscope. After heat-fixing three separate loopfuls of my unknown bacteria onto a slide, I used Methylene blue, Safranin, and Crystal violet to stain the three different samples. After rinsing the slide and observing my finding under the microscope, I

1.2 ml of the bacterial cultures are taken to pellet the cells and remove supernatant while

An unknown bacterium 15 was awarded and labeled at the table ready to be identified. Using the skills and test that are taught and learned in microbiology were applied into learning what the unknown bacteria culture was. There were multiple procedures and test done in order to gain all the information needed to determine which bacteria was given. In order to find what the bacteria was the first step was finding the right environment and temperature that would allow the bacteria to thrive and grow. Determining this is one of the most important steps in being able to obtain conclusive results that would allow the results of the test to be accurate and correct. Without the correct temperature and environment the bacteria will give inconclusive results which will alter and skew the end results and may lead to the wrong conclusion. By using the methods that were obtained and learned through the microbiology class allowed the skills and knowledge to determine the bacteria and execute the tests in order to determine the culture.

Bacteria are small, unicellular prokaryotic microbes. They have many morphologies, which include rod-shaped, spherical, spirals, helices, stars, cubes, and clubs. Classification of bacteria begins with either aerobic (requiring diatomic oxygen for growth) or anaerobic (not requiring O2 for growth). Bacteria can simply be narrowed down to gram positive (organism that stains purple or blue by Gram stain) or gram negative (organism that stains red or pink by Gram stain). Many physical and nutritional factors influence bacterial growth. Physical factors include temperature (psychrophiles, thermophiles, and mesophiles), pH (neutrophiles, acidophiles, and alkalinophiles), O2 concentration (aerobic

The petri dish lid was raised to insert the loop. The loop was touched to the agar area on the opposite side of the dish. The bacteria on the loop were transferred to the agar. The bacteria were spread in the first sector of the petri dish by moving the loop back and forth across the dish (zigzag motion).