Bacillus subtilis is a commonly used organism in the biosynthesis of foreign gene products by recombinant DNA technology (Ohmura et al, 1984). Compared to other microorganisms Bacillus subtilis has several advantages including being non-pathogenic, well-known as an industrial organism and it can secrete proteins to the culture medium (Ohmura et al, 1984). Bacillus subtilis also contains the gene for the production of the enzyme α-amylase, which works to breakdown complex carbohydrates into simple sugars such as glucose and maltose. To test for the presence of α-amylase a starch test is used. This test involves growing a culture of Bacillus subtilis on a medium along with another microorganism that is know to lack this enzyme such as E.coli. …show more content…
Requirements for this reaction to take place include the following materials DNA template, Taq DNA polymerase, primers specific to the region wished to be amplified, deoxynucleoside triphosphates (dNTPs) (Cox et al, 2015). All these elements are placed in the same test tube and briefly heated to 95℃ in order to denature the template DNA (separate the strands), this allows for the primers to move between the DNA and find the sequence of nucleotides that are to be replicated (Lodish et al, 2000). The heat is then lowered to 52℃ for the annealing of the primers to the DNA strand and then the temperature is raised once again for the Taq DNA polymerase to add onto the primers and replicate the gene of interest (Lodish et al, 2000). The temperature fluctuations are repeated for a period of time depending on how many cycles and copies of the gene is desired, in this case the cycle was repeated 34 times. A very important of this reaction is the Taq DNA polymerase which is a heat-stable form of the enzyme, which is essential to the success of the PCR reaction due to the increasing and decreasing of temperature to denature DNA and anneal primers (Lodish et al, 2000). Originally this enzyme can be isolated from bacteria that thrive in environmentally harsh conditions such as Thermus aquaticus (Lodish et al, 2000). If the target gene in the DNA template changes new primers would be synthesized specific to the new gene of interest. In the case of wishing to amplify a gene from mRNA the reaction would require RNA primers, RNA polymerase and ribonucleoside