Marry Brown
Introduction
In this experiment, the growth of four cultures, which are Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisiae (yeast) and Penicillum (mold) were examined under a range of acidic to alkaline environments to determine the pH requirements of the four species. By conducting this methodology, the range of acceptable pH limits, including the optimum pH for each organism, can be determined. The range of pH over which an organism grows is defined by three cardinal points: the minimum pH, below which the organism cannot grow, the maximum pH, above which the organism cannot grow, and the optimum pH, at which the organism grows best.
Escherichia coli are one of several types of bacteria that normally inhabit the intestine of humans. It is normally a Gram-negative, rod-shaped bacterium. It is about to survive in physiologically high temperatures that allows up to excess of 50oC. (Daniel C, 2008). However it is not able to resist temperature like endospore. Therefore, the amount of bacteria would decrease as the heating persists.
Germicides are disinfectants or chemicals used to kill germs which are mainly pathogenic microorganisms present in the environment. (Farlex, 2012) Germicides are formulated to break down and destroy pathogenic microorganisms. In this experiment, 4 types of germicides are used to control the growth of bacterial populations which are Dettol, 5% Savlon, 3% H2O2 and Listerin. A paper disc is used to transfer germicides on different bacteris. The original width of paper disc is 0.6 cm. The widths of inhibition zones caused by germicides are to be compared among each other to determine the strongest germicide.
Antibiotics are produced by microbes to inhibit growth of other microbes. Some antibiotics inhibit cell wall synthesis such as penicillin, cephalosporin, glycopeptide. Some antibiotics inhibit cytoplasmic membrane synthesis such as polymyxin B, colistin. Some antibiotics inhibit nucleic acid synthesis such as
In this experiment, the growth of four cultures, which are Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisiae (yeast) and Penicillum (mold) were examined under a range of acidic to alkaline environments to determine the pH requirements of the four species. By conducting this methodology, the range of acceptable pH limits, including the optimum pH for each organism, can be determined. The range of pH over which an organism grows is defined by three cardinal points: the minimum pH, below which the organism cannot grow, the maximum pH, above which the organism cannot grow, and the optimum pH, at which the organism grows best.
Escherichia coli are one of several types of bacteria that normally inhabit the intestine of humans. It is normally a Gram-negative, rod-shaped bacterium. It is about to survive in physiologically high temperatures that allows up to excess of 50oC. (Daniel C, 2008). However it is not able to resist temperature like endospore. Therefore, the amount of bacteria would decrease as the heating persists.
Germicides are disinfectants or chemicals used to kill germs which are mainly pathogenic microorganisms present in the environment. (Farlex, 2012) Germicides are formulated to break down and destroy pathogenic microorganisms. In this experiment, 4 types of germicides are used to control the growth of bacterial populations which are Dettol, 5% Savlon, 3% H2O2 and Listerin. A paper disc is used to transfer germicides on different bacteris. The original width of paper disc is 0.6 cm. The widths of inhibition zones caused by germicides are to be compared among each other to determine the strongest germicide.
Antibiotics are produced by microbes to inhibit growth of other microbes. Some antibiotics inhibit cell wall synthesis such as penicillin, cephalosporin, glycopeptide. Some antibiotics inhibit cytoplasmic membrane synthesis such as polymyxin B, colistin. Some antibiotics inhibit nucleic acid synthesis such as
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