November 30, 2012
Tobacco is commonly used and kills millions until this day. Tobacco is a potential mutagen due to all the chemicals added. The spot overlay Ames test was conducted to test at what concentration of tobacco was it at the most mutagenic. The hypothesis of this experiment was as the concentration of tobacco increases, the growth of bacteria increases. The control for this experiment had a UV positive and a UV negative. Four different tobacco concentrations, Salmonella Typhimurium of strain 1538 were incubated for 24-72 hours to observe bacterial growth. At a 100% bacterial growth was at its greatest number of colonization and at 5% the mutagen was at its least. These results reflected that tobacco has the ability to grow without histidine making it a mutagen and at which concentration was it the most mutagenic.
A mutagen is a substance which increases the frequency of mutation in a plant or animal population, which can lead to a variety of consequences or alterations in the DNA structure (Ligorio, Izzotti, Pulliero, Arrigo 2011). Salmonella being a mutagen can cause mutations such as substitution, insertion, deletion and frame shift depending on the strain. S. typhimurium carries a defective gene making it unable to synthesize histidine from its culture medium. Some types of mutations can be reversed with the gene regaining its function. Tobacco having lots of chemicals with possibility of being mutagenic is known to kill an estimated six million people worldwide each year and drains $500 billion annually. It can be consumed as a pesticide and in the form of nicotine tartrate. It is sometimes used in some medicines, but most commonly used as a drug. The use of Ames test is based on the assumption that any substance that is mutagenic. For this reason the FDA uses the Ames test to screen many chemicals to measures the mutagenic strength in bacterial...