TITLE:

The following paper elaborably indicates our experiement in testing the process of fermentation. Independeant Variable: water, yeast and corn syrup.

 

INTRODUCTION:

The experiment will seek to prove the hypothesis which states that, an increase in temperature increases the process of fermenataion. This is because enzymes that facilitate fermantention also break down at increased temperatures (Merritt 1965). Our experiment involved studing the effects of temperature on fermentation and to find out at what temperature would enzymes hydrolyze and stop the process of fermentation.

 According to Olaniran and Pillay, temperature changes ahs a deep effects on living organisms as enzyme catalyzed reactions are very sentive towards small variations in temperature (Olaniran & Pillay 2011). Abdel-Banat et al stated that, a 5 degrees raise in the temperature to a great extent affects the production of ethanol through fermentation process (Abdel-Banat et al 2010).

To test this, our team observed the amount of Co2, (the biproduct produced from the porcess of fermiatazion), over a preroid of thirty minutes. To ensure accuracy, our team tested the same amount utilizing the following: 6ml of corn syrup, 6ml of yeast suspension, and 2 ml of water. The controlled variable: change in temperature. The dependant variable involved the amount of Co2 produced from various temperatures over the time of thirty minutes.

Hypothesis: fermentation increases with increase in temperature. It is predicted that at at high levels of temperature, the fermentation process will be accelerated and thus more CO₂ will be produced.

 

 

 

 

 

 

 

 

 

 

 

 

 

MATERIALS AND METHODS:

First, we got four tubes, a grease pencil, 6ml of yeast, and 6ml of corn syrup and 2ml of water. We labeled the test tubes “1, 2, 3 and 4” with the grease pencil. After we added 6 ml of corn syrup, yeast and 2 ml of water in all tubes, we mixed them. Tube 1 was placed on ice at 2 degrees Celsius, tube 2 was left at room temperature at 21 degrees Celsius, tube 3 was place inside the incubator at 37 degrees Celsius, and tube 4 was place in an incubator at 50 degrees Celsius. We collected data using a chart with 5 minutes increments (stating 0 minutes to 30 minutes) and record the amount of CO₂ (air bubbles on top) in millimeters (mm).  Our dependent variable was the amount of CO₂ produced at the different temperatures. The experiment was developed based on the manual lab experiment: 0 minutes to 5 minutes no fermentation results were produced in any of the tubes. At ten minutes tubes 4 had an increment of 0.8ml. Which means fermentation was happening andCO₂ was producing.  At fifteen minutes tube 3 had 0.2 ml and tube 4 pass from 0.8 ml to 3.3 ml. At twenty minutes tube 1 which was place in ice, and tube 2 which was left at room temperature did not produce any fermentation, so any CO₂ was produce. On the other hand, tube 3 and 4 were producing a lot CO₂. Tube 3, twenty minutes passed and noticed a change from 1.6 ml of fermentation to 4.5 reaching the maximum fermentation level. While, tube 4 at twenty minutes went from 5 ml of fermentation to approximately 8-9 ml this means that fermentation and production of CO₂ happened faster at 41 degrees Celsius.

 

 

RESULTS:

The table below shows the change in rate of fermentation with change in temperatures.

	0	5	10	15	20	25	30
Tube 1 Ice 2 degrees C	0 ml	0ml	0ml	0ml	0ml	0ml	0ml
Tube 2 Room temp 25 degrees C	0 ml	0ml	0ml	0ml	0ml	0ml	0ml
Tube 3 37 degrees C	0 ml	0ml	0ml	0.2 ml	1.6ml	3.5ml	4.5ml
Tube 4 41 degrees C	0ml	0ml	0.8ml	3.3ml	0ver 5ml	Over 5ml Approx. 7ml	Over 5ml Approx. 8.9 ml

 

From the above table, the rate of fermentation can be seen to increase as the temperatures increase. At low temperatures, no rate of fermentation was experienced. The temperatures were then increased to room temperature and still no fermentation occurred at these temperatures. When the temperatures further increase to 37 degrees Celsius, the process of fermentation begins, although not as fast as in 41 degrees Celsius. At 41 degrees Celsius, the process of fermentation begins more quickly.

 

DISCUSSION:

Fermentation occurs due to the respiration process of yeast. Carbohydrates are broken down into carbon dioxide and alcohol, which leads to fermentation. For this process of fermentation to occur well, then there is necessity for optimal temperatures.

In tube 1, 2 degrees Celsius temperatures were too low. With the temperatures being that low, the enzymes are inactive hence inhibiting the occurrence of fermentation.

However, from the results, there is no solid evidence as to whether the low temperatures slow down fermentation since the experiment was not conducted for a long duration of time.

In tube 2, there is room temperature and still no fermentation observed within the time of the experiment. The temperatures are still not favorable for yeast to respire. To conclude whether these temperatures slow down the process of fermentation, the experiment would have to be conducted over a longer period of time and make more observations.

In tube 3 at 37 degrees Celsius, fermentation begins after some time. The temperatures are now high enough to facilitate the respiration process. Enzymes can respire under these temperatures and therefore leading to fermentation. It is important to note that this is the normal temperature for most warm-blooded animals.

In tube 4, the temperatures were increased to 41 degrees Celsius. It is seen that the process of fermentation hastened and there were larger volumes that were fermented within the duration of the experiment. This shows optimality of conditions for enzymes to respire. At these temperatures, fermentation occurs more quickly, an indicator that these are temperatures around which fermentation best occurs. The process of fermentation did not stop or slow down within the duration of the experiment, indicating need for test under higher temperatures.

The experiment proved our hypothesis to be true since at low temperatures the fermentation process was at minimal but as temperatures increased, the process fastened and more CO₂ was produced. Hence we can deduce and support the hypothesis that the more the temperatures, the higher the rate of fermentation.

A similar experiment on yeast indicated that when yeast is inadequately warmed that is, exposed to low temperatures, it did act much as a leavening agent as the yeast cells will slowly burn the sugar hence slowing down the process of fermentation (Olaniran & pillay 2011).

The experiment lacked sufficient temperatures and duration of time to make solid conclusions at each specific temperature. In repeating this experiment, I would recommend that sufficient time should be allocated for the experiment. Also I would find more sources of varying temperatures so as to allow a solid deduction of results at each specific temperature. Although there is a notable trend, speculation has been used to draw conclusions rather than pure observation.

 

CONCLUSION:

            From the observations and discussion, it is evident that an increase in temperature up to a certain level will increase the rate at which fermentationoccurs. However, an experiment at higher temperatures is vital since enzymes are inactive at low temperatures and are denatured by very high temperatures. Since at 41 degrees Celsius, the process of fermentation was almost optimal, a further increase in temperatures is vital to conclude how far high an increase in temperature causes an increase in the rate of fermentation.

 

 

 

 

 

 

 

 

 

References

Merritt, N.R (1965). The influence of temperatures on some properties of yeast. Retrieved on Feb 12 from http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1966.tb02977.x/pdf

Olaniran, A. O., Maharaj, Y. R., & Pillay, B. (2011). Effects of fermentation temperature on the composition of beer volatile compounds, organoleptic quality and spent yeast density.   Electronic journal of biotechnology, 14(2), 5-5.

Abdel-Banat, B. M., Hoshida, H., Ano, A., Nonklang, S., & Akada, R. (2010). High-temperature             fermentation: how can processes for ethanol production at high temperatures become        superior to the traditional process using mesophilic yeast?. Applied microbiology and biotechnology, 85(4), 861-867.