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Bacillus subtilis In this lab, there was need to choose a particular bacterium which was then to beisolated. In the experiment, Bacillus Subtilis was used as the specimen for isolation. Isolating the bacterium required knowledge about gram reaction, oxygen requirements, biochemical characteristics. The best way to isolate the bacterium was through gram staining since it helped in identification of the genus and the extent. Considering the characteristics of the bacteria, gram staining method was important since it results to a unique attribute especially in identifying whether the organism is gram positive or negative.
Further, the use of Mosel agar also helped to isolate the bacteria. This lab report consists of the results obtained for the isolation process. Introduction In this lab, the main objective was to isolateBacillus subtilis which is a gram-positive bacteria. The bacteria exist naturally in soil or vegetation; and within a mesophilic temperature range of 25-35 degrees Celsius. The bacterium has rod-shaped cells hence leading to the name bacillus. Usually, it leaves in harsh conditions, a situation leading to the formation of endospores which are stress resistant (Boone et al, 2001).
The characteristics of the bacteria which allows for the uptake of of external DNA also provided a hint in isolating the microbe from its culture. The characteristics of the organism makes it significant to make use of gram staining and mosel agar to help in the isolation process. The following is the image showing Bacillus subtilis colony MethodThe processed sample of the bacterium was treated through suspending it in a physiological saline for 15 minutes. The temperature for the treatment process was kept at 100 degrees Celsius to ensure that all the vegetative forms involved were all killed.
The culture was then isolated in a nutrient agar. Gram staining method was then applied to guide in genus identification (Dworkin & Fulkow, 2006). The shape of the rods and extent was then examined from gram stains. Further , Mosel agar was used in isolating the individual colony. Glucose nitrate was also helpful idenfying the associated growth. The color of the growth was examined and recorded. Results Gram reaction On performing gram staining, there was formation of slender rods and the realization of gram positive nature, to represent Bacillus subtilis.
This helped in isolating the microbe from B. Cereus which assumed the shape of thick swollen rods. Biochemical testWith glucose nitrate agar, the isolation was possible because of the formation of cream-colored and abundant growth.Oxygen requirementTesting by nitrates resulted in further isolation through identification of absence of gas when put under anaerobic situations.Discussion The treatment under 100 degrees Celsius was useful in isolating the species from its vegetative forms since the bacteria itself normally forms spores which help in withstanding the temperature.
Further, the use of gram staining resulted to identification of gram positive and slender rods (Bergey, 2009). This helped in isolating the species from B. Cereus which formed thick swollen rods. The use of glucose nitrate agar was also significant since it made it possible for isolation through the identification of the growth pattern. The microbe usually forms cream-colored growth which makes it unique in its culture. The main problem encountered during the process was acquiring a completely anaerobic condition when testing oxygen requirement.
Provision of nitrate broth is the best solution for future experiment done on the same since it can provide the needed anaerobic condition. References Bergey, D. H., De, V. P., & Whitman, W. B. (2009). The Firmicutes. Dordrecht [u.a.: Springer.Dworkin, M. M., & Falkow, S. (2006). Bacteria: Firmicutes, Cyanobacteria. New York, NY: Springer.Boone, D. R., Brenner, D. J., Castenholz, R. W., De, V. P., Garrity, G. M., Krieg, N. R., & Goodfellow, M. (2001). Bergeys manual of systematic bacteriology.
New York: Springer.
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