In order to determine whether Escherichia coli bacteria is present in the water sample taken from an unclean stream where different wastes are mixed, a)Which solid media do you prepare under laboratory conditions? Briefly explain, using your own sentences, what processes should be done during the time between the preparation of the medium and its pouring into the petri dish, using the devices and chemicals in the laboratory environment. b)In order to obtain pure colonies of E. coli bacteria in the water sample, which line plate method should be cultivated on the medium you have prepared and what should be considered during the procedures? Give brief information about how you identified pure and/or impure colonies after incubation. c)You also want to see both the cell morphology and the Gram result by doing Gram staining of the strain you isolated. After performing the staining process, you noticed a problem with the Gram reaction while examining the preparation under the light microscope. Because you used another laboratory culture known to be E. coli as a control during the staining process, and the images are not Gram negative as expected from E. coli. Write down what mistakes can be made in the painting process. d)At the end of the study, you will keep the pure E.coli bacteria you isolated in order to add them to your culture stock. Indicate which method you will choose by taking into account and explaining three of the factors to be considered in the selection of preservation (preservation) methods of microorganisms.