week 3 Lab report

April 13, 2017

Microbiology

Microbial Growth Lab Report

Introduction

In this lab, you are taught about the various environmental factors that encourage the growth and production of many microorganisms. You are taught and are able to learn how to place bacteria to different environmental conditions to see which conditions either encourage or discourage the growth of that bacteria along with how much bacteria are grown. Irecommend having some small previous knowledge before attempting this lab because you are given questions before and after the lab about things that deal with your experiment. This lab will teach you about osmotic pressure, nutrients, pH levels, temperature levels and atmospheric gasses. These all are key elements to microbial growth in the environment. This lab also teaches about where certain organisms thrive whether it be in extreme heat conditions, various pH levels or at really cool temperatures. Slow or lack of growth of a microorganism at various temperatures or along a pH outside the range it should be is most likely due to enzyme changes. Enzymes can be classified as proteins and their activity is dependent on the structure it is in and the pH level. You also will learn in the lab microorganism classification such as mesophiles, thermophiles, and psychophiles and these tend to revolve around temperature. These three are classified based on temperature preference. Psychrophiles grow generally below 15 degrees Celsius. Mesophiles typically grow between 20 and 40 degrees Celsius. Lastly, thermophiles thrive above 45 degrees Celsius. To give an example related to humans, optimum growth for microorganisms in humans is around 37 degrees Celsius.

Methods/Materials

You will first start off with FTM tubes accompanied with and anaerobe jar just for oxygen requirements. You first need to understand how the anaerobe jars are used so that you can determine oxygen preferences for each microorganism. To remove oxygen from an anaerobe jar, you add the chemical pack designated in the lab. If your organism can grow in the anaerobe container but cannot under normal oxygen levels, then it is a obligate anaerobe. This along with facultative anaerobes and aero tolerant anaerobes should be the only three to grow in the anaerobe jar.

Materials for this lab include:

-Agar plates -Sharpie

-Bacterial Cultures -Test Tubes

-Incubation tray

You are given sterile agar plates and samples of bacterial cultures. You are to investigate growth patterns of all the organisms on the agar plates. These plates will be incubated at regular oxygen atmospheric pressure. Makes sure you correctly know how to transfer bacterial substances between containers and use the proper tools. Along with that, make sure to properly label your samples so you know which one is which.

Results

When the lab is finished, you will be able to classify your organisms. The Escherichia coli can be classified as an obligate aerobe. The Micrococcus luteus is an obligate anaerobe. Lastly, the Clostridium sporogenes was a facultative anaerobe. Once I made my classifications, I made sure I went back over my steps to make sure I did all the techniques correctly and I did. Based on the facultative anaerobe results, you would classify it as that organism. Toxic materials used in this lab were hydroxyl, a superoxide ion, and the peroxide ot an extent. It is important to always be careful around harmful things in the lab to make sure yourself and other in the lab are safe and harm free.

Discussion/Conclusion

When I started this lab, I was honestly confused. I had to go back multiple times and re-read and learn some of the material. I also thought that all microorganisms required oxygen for their metabolism but I came to learn that was not the case at all. I also learned that facultative anaerobe organisms were more lenient with their oxygen requirements. This is because the anaerobes could potentially take advantage of the oxygen (if available) but can also process if oxygen is not present. If I was in a real life setting lab, I would kind of be a little skeptical of the harmful chemicals in a lab setting because I’d be scared I would spill something. If oxygen levels are mismatched with different organisms, depending on the organism, the effect could be either positive or negative. I would have to say that this lab is the biggest learning experience so far this quarter because I had to do a lot of research and re attempting the exercises because I was so confused at first.

Work Cited

M. (n.d.). Environmental Preferences for Microbial Growth. Retrieved April 14, 2018, from http://www.mhlearnsmart.com/flow/binrunner.html?pixi=0&isbn=1259337782&title=&deck_id=&learnsmart_id=12981612&learnsmarturl=www.mhlearnsmart.com&parisId=26183570&instructorParisId=6418639§ion_id=99815457&assignment_id=200100796&newals=0&paamskin=&first_name=Dylan&last_name=Todd&[email protected]&password=&type=S&salt=1688731042&key=b0f157c6b6f9817a8683f94c4c76c61f&assignmentDueDate=2018-04-16 03:59:00&studentExtensionDate=&isBlackBoardUrl=false&ebookLinkUrl=http://connect.mheducation.com/connect/hmEBook.do§ionURL=http://connect.mheducation.com/connect/hmStudentSectionHomePortal.do?sectionId=99815457§ionName=18SPCMP BIO-299 5&libraryURL=&preview=&plan=0&externalProductId=A9S0004102