The Inhibitory Effect Of Heavy Metals, Such As Hg, Cu and Ag, on the Growth of B. Cereus, E. Coli, M. Luteus and P. putida
             For over two hundred years, since the beginning of industrialization, man has searched for effective methods of controlling diseases and the growth of bacteria in various different fields (for example, in the eutrophication of lakes). Heavy metals have been a common component used to control the spread of bacteria, some working to a greater extent than others on assorted types of bacteria. However, is there a heavy metal that controls a wide range of bacteria effectively, or must we continually use specific elements on select types of colonies in order to achieve near-sterility? The purpose of this lab report is to, if possible, identify one particular heavy metal that effectively inhibits growth of all the selected bacteria, or identify whether each type of bacteria has a specific heavy metal that has a more powerful effect in controlling growth. This study is important in that if one heavy metal can be found to inhibit the growth of bacteria most effectively, then antiseptic industries may choose to use one particular heavy metal over others in sterilizing solutions.
             Four types of bacteria will be focused on in this study: B. cereus, E. coli, M. luteus and P. putida. Each will have the effects of three heavy metals, which are in solution form, tested on them. The heavy metal solutions to be used will be mercuric iodide (HgI2), silver nitrate (AgNO3), and copper sulfate (CuSO4). Their effectiveness will be judged on the size of the zones of inhibition that form around the filter paper soaked in the solutions. I predict that overall the mercury compound will have the most detrimental effect (and therefore larger zones of inhibition) on the four selected bacteria types, since it is known that, in general, it has very harmful effects on other living organisms. A similar study conducted by Schmidt and Schlegel on ...