Thinking back to experiment 3, Aseptic technique and microbe culture, I realized the large quantity of microorganisms that can be found in everyday life. Many different types are found in the human body. These experiments focused on two types of bacteria. The first was Staphylococcus epidermidis, found on the skin, and the second was Lactobacillus acidophilus, found in the gastrointestinal tract. Both have similar growth requirements regarding temperature, however different growing environments are used. In order for growth to occur, microorganisms need to obtain energy. One of these ways is using oxygen or not using oxygen. Microorganisms that require oxygen are obligate aerobes. It is essential that these obtain oxygen for growth, they receive energy from aerobic respiration which requires oxygen. Microorganisms that do not necessarily require oxygen are known as facultative anaerobes. These organisms are able to grow with or without the presence of oxygen. They obtain energy from aerobic respiration if oxygen is present. Facultative anaerobes are capable of switching to fermentation or anaerobic respiration if oxygen is not present. Staphylococcus epidermidis and Lactobacillus acidophilus are both facultative anaerobes, which do not always require oxygen to grow. There are also temperature requirements for growth to occur. Microorganisms are divided into different groups depending on their preferred temperatures. The first type is psirophiles. These bacteria prefer cold weather. It is usually found in minus five degrees Celsius up to fifteen degrees Celsius. Generally located in the Antarctic and Arctic regions, they feed on runoff from glaciers. Next is Mesophiles. These bacteria prefer to grow... in the center of the paper... a moderate surface. Finally, tubes or depths are tubes filled with hardened agar medium and are used by inserting the inoculum into the agar. The two different media used in this experiment were nutrient broth for growing Staphylococcus epidermidis and MRS broth used for culturing Lactobacillus acidophilus. After observing the two cultures at the end of twenty-four hours, neither showed signs of growth. It was only after the forty-eight hours that there were signs of growth. Nutrient broth containing Staphylococcus epidermidis has become cloudy or cloudy. MRS broth containing Lactobacillus acidophilus had increased sediment. I feel like I didn't see any growth at the twenty-four hour mark due to the possible inappropriate temperature. I adjusted the temperature to try to stay at thirty-seven degrees Celsius.