The Effect of Heat and Growth on the Survival of Bacteria
Aims
The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.
The second part of the experiment was to examine the effect temperature had on the survival ability of the five bacteria mentioned above. One of the five bacterial species were allocated per work bench for individuals to create broth culture with and expose to temperatures of 40, 60, 80 and 100°C for 2, 5, 30 and 90 minutes. As the same in experiment one, these cultures were then left for a week to incubate, then upon completion they were observed for distinguishable changes, such as the turbidity, clarity and the formation of endospores to show the bacteria’s survivability at particular temperatures. Information was then collated from other work benches to show the results from all five species.
Results
Table 1. Table of results showing the effect temperature has on the growth and survival of bacteria. Temperature | 5°C | 25°C | 37°C | 45°C | 55°C | Organism | | | | | | Escherichia coli | 0 | 2 | 3 | 3 | 1 | Pseudomonasfluorescens | 2 | 3 | 1 | 0 | 0 | Enterococcusfaecalis | 0 | 1 | 2 | 1 | 0 | Bacillussubtilis | 0 | 1 | 2 | 2 | 3 | Bacillus stearothermophilus | 0 | 0 | 0 | 2 | 3 |
0: No growth 1:Light growth 2:Medium growth 3:Heavy growth
The table above shows the level of growth for each species of bacteria at various temperatures. The example of Escherichia coli showed no
The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.
The second part of the experiment was to examine the effect temperature had on the survival ability of the five bacteria mentioned above. One of the five bacterial species were allocated per work bench for individuals to create broth culture with and expose to temperatures of 40, 60, 80 and 100°C for 2, 5, 30 and 90 minutes. As the same in experiment one, these cultures were then left for a week to incubate, then upon completion they were observed for distinguishable changes, such as the turbidity, clarity and the formation of endospores to show the bacteria’s survivability at particular temperatures. Information was then collated from other work benches to show the results from all five species.
Results
Table 1. Table of results showing the effect temperature has on the growth and survival of bacteria. Temperature | 5°C | 25°C | 37°C | 45°C | 55°C | Organism | | | | | | Escherichia coli | 0 | 2 | 3 | 3 | 1 | Pseudomonasfluorescens | 2 | 3 | 1 | 0 | 0 | Enterococcusfaecalis | 0 | 1 | 2 | 1 | 0 | Bacillussubtilis | 0 | 1 | 2 | 2 | 3 | Bacillus stearothermophilus | 0 | 0 | 0 | 2 | 3 |
0: No growth 1:Light growth 2:Medium growth 3:Heavy growth
The table above shows the level of growth for each species of bacteria at various temperatures. The example of Escherichia coli showed no
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