Oxygen Requirements for Growth Obligate aerobes-require O2 to live Facultative anaerobes-use O2 and can switch to fermentation if O2 is gone Obligate anaerobes-required to live in absence of oxygen Aerotolerant anaerobes-cannot use O2 for growth, but tolerate it well Microaerophiles-require O2 at levels lower than atmospheric O2
How Microbes Tolerate Oxygen Enzymes that allow obligate aerobes and facultative anaerobes to grow in oxygen Superoxide dismutase Catalase Peroxidase
Oxygen Detoxifying Enzymestype of microbe catalase superoxide comments dismutaseobligate present present oxygenaerobe and toleratedfacultativeanaerobeaerotolerant absent present oxygenanaerobe toleratedobligate absent absent oxygenanaerobe and toxicmicroaerophile
Growth of Microbes in Agar Delta biology. Oxygen Requirements of Bacteria. 2012. Accessed March 22, 2012: http://deltabiology.com/2011/oxygen- requirements-of-bacteria/
Questions for Consideration:In the following slide:Which is the obligate aerobe?Which is the obligate anaerobe?Which is the facultative anaerobe?Which is the microaerophile?