Effects of Osmotic Stress and Temperature on Microbial Growth

In the S. cerevisiae specimen, moderate growth was expected and observed based on the knowledge that most microbes desire this type of environment for growth. The same was expected although a larger amount of growth was observed for the S. epidermidis specimens in the 1% NaCl solution than expected. The 1% NaCl solution provided the best environment for the growth of both microbes. Minimal growth of S. cerevisiae and moderate growth of S. epidermidis was observed from the 7% NaCl solutions. The S. epidermidis is used to a slightly salty environment on the surface of skin which may account for the higher growth over S. cerevisiae in this environment. Lastly, no growth was noted in either specimen of 15% NaCl. This type of environment does not support the growth of most microbes due to the increase in salt content and the hypertonic environment it creates.

The temperatures tested were 4°C, 30 °C, and 60°C. The optimal growth and prodigiosin production

The purpose of the following study is to determine where the two unknown bacteria acquired in Microbiology lab should be classified in regards to temperature, pH level, and osmoregularity. It is important to classify bacteria in order to identify them. Identification of bacteria is important because they are not only useful but potentially dangerous as well. The identification of bacteria can lead to breakthroughs in healthcare regarding treatment of old and new diseases alike. Identifying bacteria can also be used in many other areas from better crop production through microbial pesticides to biological warfare. Their uses are endless as are their abilities to evolve and adapt to changing environments. That is why it is so important

70µL of competent E.coli are added to both test tubes; pUC18 and Lux (Alberte et al., 2012). Both test tubes are then tapped and placed back into the ice bath for 15 minutes. While waiting, another test tube is obtained, filled with 35µL of competent cells and labeled NP for no plasmid. A water bath is preheated to 37 degrees Celsius and all three labeled test tubes are inserted into the bath for five minutes (Alberte et al., 2012). Using a sterile pipet 300µL of nutrient broth are inserted into both the control and Lux test tubes and 150µL are inserted to the no plasmid test tube to increase bacterial growth. All three test tubes are then incubated at 37 degrees for 45 minutes. Six agar plates are obtained and labeled to correspond each test tube, three of the plates contain ampicillin. A pipet is used to remove 130µl from each test tube containing a plasmid and insert it into the corresponding agar plate. For this, a cell spreader is first

Finally there is the Hyperthermophiles. Found in very hot temperatures such as hydrothermal vents in deep oceans. With this said, the two microorganisms that I worked with would be known as Mesophiles. Both of these microorganisms grow on or in the human body. They prefer moist heat that is body temperature. I made an incubation box to help mimic the temperatures needed. Typically trying to maintain the temperature of thirty seven degrees Celsius.

When testing this certain type of bacteria the warm temperature caused it to grow exceptionally fast comparted to the room temperature. Bacteria are single celled microbes. The cell structure is simpler than that of other organisms as there is no nucleus or membrane

The objective of this experiment is to see how safe bottled and tap water is to drink based on what is in the water; specifically the contaminants and the pH balance of the water. As well as if the temperature of the environment that the water is placed in affects the pH balance of the water along with if bacteria is grown due to the condition it is in. Water is one of the most important things in life, being as it is known as the universal solvent, and humans and many other animals need it to survive. Along with water, the balance of pH is also extremely important in the maintenance of any organism 's life, including the lives of humans. Temperature is known to affect the speed of movements of ions within a solution. There are specific

9. In the research done on the microbial community in the Rhizosphere using two methods, which are the Cultivation-dependent method and Cultivation-independent method. The research and studies done had good results, moreover, the physiological profiling was done in 5 days by the use of several carbon sources. The maximal growth was observed for the 30 degrees celsius- incubated plate by day 3, whereas comparable values were recorded for the room to the temperature-incubated plate by day 5.

This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

Being able to control bacterial growth is something that is important in our everyday lives. As shown in the previous labs, bacteria can grow and create colonies extremely quickly especially in the right environments. By acknowledging this, it is then important to get an understanding of how bacterial growth can be controlled by humans. To control microorganisms it means to inhibit their growth (static) and or kill them (cidal) (Kenneth Todar, 2015); therefore since focusing on bacteria the terms bactericidal and bacteriostatic are both extremely important for this lab. One broad method we will use to control bacterial growth is heat. The amount of heat needed to control bacterial growth is different for different species of bacteria (Kenneth Todar, 2015). Bacteria can also respond differently depending if moist heating method such as an autoclave with steam is used, or a dry heating method such as inoculating a loop over a fire is used (Kenneth Todar, 2015). UV works by damaging the cells DNA, without proper DNA, the cells will die and the object

Isolate a pure culture on Biolog recommended agar media (BUG+B or Chocolate Agar) and incubate at 33°C. Some species may require special culture conditions, for example either lower or higher temperature (26° - 37°C.) or elevated. The cells must be freshly grown since many strains lose viability and metabolic vigor in stationary phase. The recommended incubation period for most organisms is 4-24 hours. Spore forming gram-positive bacteria (Bacillus and related genera) should be grown for less than 16hours to help minimize sporulation while on the agar medium.

: All bacteria have an optimum environment and temperature in which they thrive the most. Most bacteria grow within a particular temperature range each with a minimum, maximum and optimal temperature. When a bacteria is grown below its optimal temperate, the metabolic process occurs more slowly, therefore not allowing the bacteria to grow to its potential. When a bacterium is grown above its optimal temperature the enzymes become denatured therefore slowing the process of growth. Bacteria have three different classifications based on growth and temperature properties; psychrotroph, mesophile, thermophile. Thermophiles thrive in hot/warm conditions due to an enzyme that allows them to be non readily destroyed or deactivated by heat. A thermophile

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.

This experiment was performed to test the hypothesis if LB nutrient broth, +pGLO and -pGLO Ampicillin, and Arabinose was placed in the E. coli plates, then there will be a significant growth in the newly transformed bacteria and it will possess the ability to glow under UV light. The measurements were recorded from the bent glass tube in each glass test tube. The transformation protocol tested for the newly possessed traits in E.coli bacteria. Throughout the experiment there were many probable reasons for failure. If the pipettes and sterile loop were not thrown out in between each use, a cross contamination could cause a miscalculation in the experiment causing the data results to fail. The hypothesis that was tested was validated due to the positive results with each experiment stating that newly transformed organisms due in fact pass on traits.

A fresh pipette was used to transfer 0.5ml of broth culture of E. coli, to be inoculated, into a tube of molten agar previously boiled to drive off oxygen. The tube was then rolled to distribute the bacteria and allowed time for the agar to harden. The tube was incubated at 37oC for 48 hours. The procedure was repeated for broth cultures of the bacterium Clostridium sporogenes and B. Subtilis.