Microaerophilic and Facultative Aerobic Prokaryotes

A strategy of adapting to aerobic/anaerobic environments is the ability to switch metabolisms. Facultative aerobic bacteria can produce energy by respiration or fermentation. Many species are enterobacteria. There are many pathogens from the genera Salmonella , Shigella , and Vibrio . The number of indicator species Escherichia coli or physiologically similar coliforms is a common indicator of water pollution by feces or sewage. A strategy of adapting to low oxygen concentrations is microaerophilic growth. Microaerophiles can form hydrogen peroxide, superoxide, or hydroxyl radicals as the final products of oxygen detoxication. The growth of microaerophilic filamentous bacteria in poor aerated or overloaded aerobic tanks may be a reason for the bulking of activated sludge. A quiz bank is added to this chapter.