Question

Mesophilic organisms are organisms that prefer moderate temperatures (not too hot, not too cold). Their enzymes are similar to the potato enzymes, they work best at a range of 20-40 °C. What do you deduce is happening during the mesophilic stage? Why do the mesophilic organisms stop working at around 45°C?

2. Thermophilic organisms are organisms that survive best in hot temperatures (up to 70°C) What do you think is happening during the thermophilic stage of the compost pile?

3. Why does the curve peak (around 65°C) and not continue rising as temperature continues to increase?

4. Why do you think that, after some time, the curve begins to decline?

5. Does your data show any evidence that extreme heat has an effect on the ability of catalase to carry out its reaction, and if so, what is this evidence?
6. At what temperature did the potato enzyme work best?
7. What range of temperatures do you deduce are the best for potato catalase activity?

Answer 1

1. Mesophilic organisms are organisms that prefer moderate temperatures. The lowest temperature at which the organism can survive and replicate is called minimum growth temperature and , the highest temperature at which growth can occur is the maximum growth temperature. That is the reason  mesophilic organisms stop working at around 45°C since they are adapted with optimal temperature ranging from 20 degree celcius to 45 degree celcius. The majority of human pathogens are mesophile since our normal body temperature is 37C. eg Staphylococcus aureus, Escherichia Coli.

2.Thermophilic organisms are organisms that survive best in hot temperatures (up to 70°C). Composting is a kind of process in which natural decay of organic material is happening with the help of microorganisms in the environment that feed on the decaying detritus.

Mainly there are three stages in composting cycle. The first stage is just for few days in which mesophilic microorganisms begin physically breaking down the biodegradable compounds. Heat is a natural byproduct of this initial process and temperature will rise to 40 degree C. In the second stage, mesophilic organisms are replaced by thermophilic microorganisms and it will last from a few days to several months. Temperature continues to rise and the compost pile can get so hot that it can kill off all the helpful microorganisms. In third stage, temperatures become down and mesophilic microorganism started resuming control of the compost pile and thereby finish breaking down the remaining organic matter into usable humus.

3. The curve peak (around 65°C) does not continue rising as temperature continues to increase because in this temperature mesophilic organisms are replaced by thermophilic microorganisms and it will last for several months.

6. The potato enzyme works best at 30 degree celcius.

7. The range of temperatures best for potato catalase activity is 35.3°C and 43.5°C