Discuss how the simulated lab reports can help you identify unknown bacterium.
Most bacteria are identified using culture media with specific requirements. Culture media usually provide a suitable environment for the growth of certain bacteria. Each of the simulated labs contributes to information that can help in the identification of the unknown bacterium (Basu et al,2015). For example, in the first lab, bacteria were grown in a petri dish using agar. Thus, it can be deduced that either Staphylococcus or Streptococcus grew on the plate because of the suitable requirements provided by agar for their growth (Khurana et al,2015). In the second lab, gram staining is a technique that enables bacteria to be differentiated into two. Therefore, the results obtained will allow us to differentiate bacteria with thick peptidoglycans such as Lactobacillus and Streptococcus or thin peptidoglycan such as Escherichia coli (Galani et al,2010). The third experiment involved the production of a pure culture by transfer of a colony to an agar slant. From this experiment, it can be identified that the bacteria that grew on the pure culture was Escherichia coli.
The fourth lab test involved a catalase test, and enzyme catalase is found in bacteria exposed to oxygen (Hadwan et al,2016). Therefore, we could establish that possible catalase-positive bacteria could be Micrococci and Staphylococci while catalase-negative bacteria could be Enterococcus spp and Streptococcus (Abed et al,2016). The fifth experiment was done to investigate cultural characteristics using nutrient agar plates, nutrient agar slants, and nutrient broth slants. The distribution of colonies was recorded, and it could be deduced that Staphylococcus and Streptococcus grew on the nutrient agar plates and slants while Escherichia coli most likely grew on the nutrient broth due to its ability to grow in liquid media. The last experiment involved differential staining. In this experiment, the bacteria present could be identified using the concept of gram-negative, for example, Escherichia coli and gram-positive bacteria such as Lactobacillus. Don't use plagiarised sources.Get your custom essay just from $11/page
Highlight all the properties and cultural characteristics of a bacterium present in one of the simulated lab exercises.
One of the bacteria that is common in the above simulated lab tests is Escherichia coli. This bacterium is a member of the Enterobacteriaceae family; it is commonly known as E. coli and is frequently found in water supplies. This bacterium is rod-shaped that aids the motility of the bacterium and it is gram-negative due to its thin peptidoglycan cell wall (Malanovic,2016). Escherichia coli is catalase-positive because it requires oxygen for respiration, and it is a facultative anaerobe. E. coli displays cultural characteristics in different culture media (Liang et al,2017). On nutrient agar, E. coli appears as a white, circular, opaque substance. It can have smooth and rough variations due to repeated sub-culture. On blood agar, it forms big, gray, circular colonies that are hemolytic.
On MacConkey agar, it forms colonies that are circular, moist, pink, flat, and are lactose-fermenting. E. coli forms pale straw colonies on Mueller Hinton Agar, also known as MHA. On liquid media, it forms sediments at the bottom of test tubes and massive deposits that disperse upon shaking. This is similar to its characteristic in nutrient broth whereby a deposit disperses on shaking (Jarboe et al,2017). The growth of E. coli colonies is inhibited in selective media such as Desoxycholate citrate agar (DCA). However, any colonies formed display a pink color due to the presence of lactose and neutral red (Liao et al,2017). This bacterium is non-spore forming, thus it does not have endospores. Endospores usually form in bacteria that are gram-positive, and it usually develops as a result of a deficiency in nutrients. Endospores play a role in survival, protection, and passage to the host, which is not needed by E. coli bacteria.
References
Basu, S., Bose, C., Ojha, N., Das, N., Das, J., Pal, M., & Khurana, S. (2015). Evolution of bacterial and fungal growth media. Bioinformation, 11(4), 182.
Hadwan, M. H., & Abed, H. N. (2016). Data supporting the spectrophotometric method for the estimation of catalase activity. Data in brief, 6, 194-199.
Liang, X., Liao, C., Soupir, M. L., Jarboe, L. R., Thompson, M. L., & Dixon, P. M. (2017). Escherichia coli attachment to model particulates: The effects of bacterial cell characteristics and particulate properties. PloS one, 12(9), e0184664.
Malanovic, N., & Lohner, K. (2016). Gram-positive bacterial cell envelopes: The impact on the activity of antimicrobial peptides. Biochimica et Biophysica Acta (BBA)-Biomembranes, 1858(5), 936-946.
Miriagou, V., Cornaglia, G., Edelstein, M., Galani, I., Giske, C. G., Gniadkowski, M., … & Peixe, L. (2010). Acquired carbapenemases in Gram-negative bacterial pathogens: detection and surveillance issues. Clinical microbiology and infection, 16(2), 112-122.