These mean the status which the media must ascertain before they can support the growth of bacteria, moisture, carbon, and nitrogen substance are very essential for artificial media to meet there requirement in other to support the growth of micro organism. Just like animal cannot survive without water, also micro organism cannot survive without moisture. Moisture perform a significant role in the nutrition of bacteria, take for example the drying of food for preservation occur because bacteria that is liable to destroy the food stuff cannot withstand a dry condition, it prevent them from multiplication although did not kill the bacteria totally.
Nitrogen: the way which nitrogen is added to medium depend on their enzymatic reducing power of the organism the simplest way of adding nitrogen to media is by addition of peptone.
Carbon is also supply to the media by broken down amino acid given out by catabolism of peptone some bacteria growth well when blood and serum are added to culture media. Other condition which pathogenic bacteria may required for growth is the environment, a favorable environment aid bacteria to grow well with artificial media. Gas is another essential factor required by the bacteria to growth.
Some of the organism growth in the present of oxygen are called aerobic organism.
Some growth in the absent of oxygen called anaerobic organism,
some are called facultative because they can growth in the present of either oxygen and carbon dioxide, while some grow best in an atmosphere containing reduce concentration of oxygen this organism are called microphilic.
Anaerobic organism grow base on the state of their redox in their environment, the redox measure the power of the oxidation and reduction in the solution.
Measurement is carried out by inserting electrode into the solution examine and record the electrical power of the solution set between the electrode inserted into the solution. The electrode power is called Eh and S.I unit is measure in mill volts. The oxidation of the system depends on the high power of the electrode. Demanding anaerobic micro organisms are not able to growth in the culture media until the power of electrode is obtained in certain low level. The reason on why anaerobic organism doe not grow in the present of oxygen is that many of micro organisms produce hydrogen peroxide (H2O2) when oxygen are present in the incubator. Aerobic micro organism poses enzyme called catalase, these enzyme help in broken down the hydrogen peroxide form when they are incubated in the present of oxygen, the broke down product form hydrogen and water. While anaerobic micro organism lack the enzyme so they not able to broke down hydrogen peroxide to hydrogen and water. The hydrogen peroxide are toxic chemical that destroyed micro organism, so when they are incubated in the absent of oxygen there will be no formation of peroxide formation as a result of that the organism is able to growth well in the incubator.
Be the first to comment