Bacteria Growth Requirements
Life as we now it has ended. What is left you ask? Well it is said the only thing that could survive an incident that could end our known way of life is a roach and a pack or Twinkies. In truth the great survivor would be microorganisms. Microorganisms can survive where most cannot due to their size, nutritional needs, energy requirements, and are very good at adapting to different environments (Black 2008). Microorganisms require two things to live a long healthy life, and these are physical and nutritional factors. Physical factors include pH, temperature, oxygen concentration, moisture, hydrostatic pressure, osmotic pressure, and radiation (Black 2008). Nutritional factors include carbon, nitrogen, sulfur, phosphorus, trace elements, and sometimes vitamins (Black 2008). For the purpose of this exercise I will focus on E.coli. Pathogenic Escherichia coli will be discussed since it is a common, but dangerous bacterium. E.coli in humans is found in the intestines. This bacterium is very durable, meaning that it is well-adapted to its habitat. For example, it can grow with glucose being the only food source. This bacterium can also grow with or without O2. If located in anaerobic habitat it can it will use the fermentation process producing mixed acids and gases (Todar 2012). This bacterium has shown that it can also use anaerobic respiration when NO3 or NO2 is available. Chemicals, pH, temperature, are a few signals that determines how E.coli will respond (Todar 2012). When it senses a change in the environment it can swim toward or away from anything useful or harmful. Temperature can also affect E.coli. A change in temperature allows E.coli to change pore diameter of its outer membrane to accommodate certain nutrients, or to exclude something harmful. E.coli also rations its nutrient supply by taking in account how much is available in its environment. This means that it will not take in nutrients unless...
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