Introduction
Microorganisms are among the most numerous non-living entities on earth. The presence of microorganisms increases the risk of numerous illnesses in both people and plants. Fungi, viruses, and bacteria are the three types of microorganisms that are categorized. These bacteria are present everywhere people travel in their daily lives. People meet microbes without ever seeing them because the majority of them are minute life forms (about a cell thick) that can only be seen under a microscope. In this way, it is essential to manage the presence of certain life forms that are dangerous to human life. There are two different ways to help control microorganism existence; through the use of chemicals, or by killing them (D'ans, Gottlieb and Kokotovic, 1972).
Methods
The basis of this experiment involves control of microorganisms through the use of UV and high temperatures. Through the use of heat and UV rays, microorganisms' growth can be controlled, or they can be utilized to kill them altogether. High temperatures and UV can regulate their growth because these two conditions inhibit the composition of the control media that stimulates the development of various microorganisms. UV are beams that reach earth straight from the sun while the high temperatures are human-made means developed for the purpose of increasing the surrounding temperature to control bacterial development as indicated by Kirchman, Rex, Malmstrom, and Matthew (2005). High temperatures can be achieved in two forms, moist, and dry heat. Dry heat is as a result of direct contact with a heat source such as a fire, while wet warmth involves the utilization of water baths or steam. High temperatures cause microorganisms to die which makes the use of heat a viable method for equipment sterilization.
Materials and Methods
There were three parts in this experiment. The first part involved determining the impacts of heat on the development of bacteria for the Bacillus subtilis and Serratia marcesens. This part involved the use of three TSA plates partitioned into equivalent parts. The bacteria were put into these parts. Each TSA plate was set at a different temperature for two full days: 4°C refrigerator, 25°C incubator, and 37°C incubator.The second part involved the use of UV rays on the bacterial growth for Bacillus subtilis and Serratia marcesens. In this part, two TSA plates, divided in half, were used; B. Subtilis was introduced into one, and the other with E. coli. One side of both plates was marked as UV exposure, whereas the other side was the control. For the purpose of streaking inoculate the agar plates, a sterile swap was used. One side was exposed to UV for five minutes while an index card covered the control side. The plates were then placed in the 37°C incubator for two days.The third part entailed the controlled growth of microorganisms utilizing heat for E. coli and B. subtilis. This step comprised of three trypticase soy tubes. Heat from water baths at distinct temperatures was used as the heat source for the experiment. E. coli was inoculated into tube 1 for ten minutes at 55°C. E. Coli was likewise inoculated into tube 2 but with a different timeframe, twenty minutes. There was inoculation of B. Subtilis into tube 3 for ten minutes, at 55°C. Every understudy was allocated a different time/temperature for both bacterial species. The temperatures used were 100°C, 80°C, 55°C, and 40°C, for equal time allotments of 40 minutes, 30 minutes, 20 minutes, and 10 minutes. Finally, the outcomes were then consolidated.
Results
To find out which strategy had the best impact on the bacterias' inhibition or development inspection was done on each of the broth tubes and plates from every procedure. The patterns of growth for the heat control procedure will identify the bacterias' thermal death points and times.
Control by UV Light
Control by Temperature
Figure 4: B. subtilis. Right side is the control while the left had light exposure. No observable growth on the left side.
Figure 1: S. marcesens/ B. subtilis
4°C in the refrigerator. No observable growth
Figure 2: S. marcesens/ B. subtilis
At 25°C
Figure 5: E. Coli. Right side control and left exposed to light. No observable growth on the left side.
Figure 3: S. marcesens/ B. subtilis. At 37°C incubation
Control by Heat
Temperature (°C)
40°C
55°C
80°C
100°C
Time (Minutes)
10
20
30
40
10
20
30
40
10
20
30
40
10
20
30
40
E. coli
X
X
X
X
X
X
X
X
X
X
X
X
X
X
O
O
B. subtilis
X
X
X
X
O
O
O
O
O
O
O
O
O
O
O
O
Figure 6: The bacterial species' growth is presented in various temperatures for given measures of time where (X) shows bacterial development and (O) signifies a lack of growth.
Results
When the microorganism absorbs UV rays, the rays hinder DNA replication which leads to unrepairable DNA damage and thus inhibits their development. UV light can likewise cause the microorganisms' death. The outcomes from the UV test showed that the plates exposed to UV rays demonstrate no bacterial growth. As a result, numerous died (Oguma, et al. 24). The control, on the other hand, had another outcome. The microbes in these plates did not die and also duplicated. As a result of the colonies' numbers, it was determined that the E. Coli plate was more affected by UV light compared to the B. subtilis plate.In the heating procedure, the outcome demonstrates that the two microorganisms' temperature tolerance varies. After 20 minutes, B. Subtilis' thermal death point was 100°C while E. Coli's thermal death point was 55°C. At 40°C, E. Coli had no thermal death point. Thirty minutes was B. Subtilis' thermal death time at 100°C. During the impacts of heat procedure on S. marcesens and B. Subtilis, the microorganisms only grew at 37°C and 25°C. There was no visible growth at 4°C in the refrigerator.
Conclusion
In conclusion, a lack of awareness can prompt a bacterial populace being depicted as resistant as a result of constant exposure to similar controlled development conditions which cause the bacteria's body mechanism to build up a protective system against the controlled development conditions. The sun is the primary source of UV beams; the rays' intensity can be diminished because of the ozone layers' presence causing gross impacts while also leading to preventive bacterial development on various media. Warm requires more contribution on a conservative premise, there is a requirement for a suitable source that is less exorbitant, and the source must have the capacity to create high temperatures that counter the development of microorganisms. UV rays and warmth counteract proliferation of microorganisms thus short living their reality in a specific region. The sun's UV light, and heat from a man-made source, for example, Bunsen burner represses the development of endospores created by Bacillus species.
References
D’ans, G., Gottlieb, D., & P. Kokotovic. (1972). Optimal control of bacterial growth. Automatica 8.6: 729-736.
Kirchman, David L., Rex R. Malmstrom, & Matthew T. Cottrell. (2005). Control of bacterial growth by temperature and organic matter in the Western Arctic. Deep Sea Research Part II: Topical Studies in Oceanography 52.24: 3386-3395.
Thingstad, T. F., & R. Lignell. (1997). Theoretical models for the control of bacterial growth rate, abundance, diversity and carbon demand. Aquatic Microbial Ecology 13.1: 19-27.
