Microaerophiles going to the top of the ...

Clostridium botulinum, and obligate anaerobic - Public Health Image Ligrary # 1979 Although the need for a breath of life, the special role played by oxygen to sustain life is not easy to understand. In fact, in organisms that can use it, the oxygen molecules to allow food to be destroyed, so that every possible bit of energy is extracted for use in the management of the cells, the cells from those that make up the human body to tiny one-celled bacteria. Organisms that can use O2 for aerobic metabolism known. Oxygen can actually be quite toxic, and the cell in order to be able to use molecular oxygen, it must be able to produce specific enzymes that detoxify oxygen waste products. Aerobic strattera 10mg production of catalase and superoxide dismutase (SOD) for this purpose. There are many types of microorganisms (bacteria and fungi) that can survive in the absence of oxygen. These bacteria either do not have the enzymes necessary to neutralize the waste of oxygen, or they can not do enough of these enzymes to be able to live normal levels of atmospheric oxygen. These bacteria are called anaerobes. They are still able to break down food molecules in the absence of O2, but can not make it as effective as aerobic. Although they could not get the same amount of energy from food, as a anaerobe has its advantages. Microbes that do not require oxygen are able to live in places where the aerobes can not survive, such as the human gut, and many other places where oxygen is in low supply. For pathogens (those that cause disease), this ability is a huge advantage, allowing anaerobic pathogens to cause disease in the body that are not exposed to oxygen. In microbiology, there are special terms used to describe the relationship of microbes with oxygen. Here are the main categories:

obligate aerobes: these organisms should be oxygen to survive. People and

Bacillus bacteria are just two examples of obligate anaerobes. Obligate anaerobes: These microbes are killed in the presence of oxygen. An example would be members of the bacterial genus

Clostridium. Although

C. tetanus

(Agent tetanus), C. botulinum

(agent botulism),

C. perfringens

(agent of gas gangrene) and C. difficile

(cause pseudomembranous colitis) die in the presence of oxygen, the members of this genus are capable of producing endospores, structures that allow the endospores of producing dormant in adverse conditions. Facultative anaerobes: These microbes are able to exist without oxygen, but if you have a choice, prefer to have access to oxygen, in order to get the maximum amount of energy from the metabolism of food. Many yeasts, enteric bacteria such as gram-negative Escherichia coli

, as well as gram-positive skin residential halophiles as

staphylococci are facultative anaerobes. Microaerophiles: These bacteria require oxygen, but at a level lower than that found in the atmosphere. Helicobacter pylori, the cause of stomach ulcers is microaerophile. Aerotolerant Anaerobes: These microbes do not depend on oxygen. They can not use it, but it does not hurt. Lactobacillus bacteria, which are part of the normal flora of the intestine are aerotolerant. To learn more about microbiology, see Todars Book Online or bacteriology. Here is the key to information relating to the second photo (the bacteria in liquid culture, and oxygen) associated with this article. The following may help clarify the different types of relationships that microbes are oxygen. Various aerobic bacteria behave differently when grown in liquid culture ... Obligate aerobic bacteria gather at the top of the tube to absorb the maximum amount of oxygen. Obligate anaerobic bacteria gather at the bottom to avoid oxygen. Facultative bacteria are collected mainly at the top, as aerobic respiration is the most energy efficient, but as a lack of oxygen does not hurt them, they can be found throughout the tube. Microaerophiles going to the top of the tube, but not at the top. They need oxygen, but at lower concentrations than found in the atmosphere. Aerotolerant bacteria are not affected by oxygen, and they are uniformly distributed over the tube. .