Overview Diagram illustrates various types of oxygen requirement for growth, with those bacteria closest to air in tube being most dependent on oxygen for metabolism Aerobes ("Nagging Pests Must Breathe") Nocardia Pseudomonas Mycobacteria explains TB's preference for the apices of the lung (highest PO2) Bacillus Bordatella Anaerobes ("ABC") Actinomyces Bacteroides Clostridium Microaerophilic ("a bit of air for 'bacter") Campylobacter Helicobacter Borrelia burgdorferi Facultative anaerobes Lactobacillus most other bacteria! Physiology Aerobes depend on O2 to generate ATP Anaerobes normal in GI tract but otherwise pathogenic lack catalase and/or superoxide dismutase more susceptible to oxidative damage foul-smelling due to short-chain fatty acids hard to culture produce gas in tissue "aminO2glycosides" are ineffective against anaerobes because these antibiotics require O2 to enter bacterial cell Microaerophilic requires oxygen, but requires low levels of oxygen