Purpose: To learn and employ aseptic technique and basic forms of culture media as well as become familiar with the basic requirements of microbial growth and the methods used to control microbial growth.
Procedure: Obtained a small Styrofoam cooler placed two small light bulbs in side and observed temperature over 24 hours to ensure temperature could be maintained between 98-100 degrees. Using a 10% bleach solution I then cleaned my work area. Transferring one capsule of L. acidopholis into a tube of MRS broth using the aseptic transfer technique then marked a line on test tube to record sediment. Labeled tube of nutrient broth S. epidermidis, then using a sterile swab obtained sample of bacteria from skin then transferred using the aseptic transfer technique into the sterile media. Incubated both specimens for 48 hours observed and recording results of growth at 24 and 48 hours. After observing final growth pattern at 48 hours prepared both wet mount and direct stain slide for each of the cultures. Viewed under microscope using both the 40X and 100X oil immersion lens. Disinfected work area.
|Bacteria |Growth pattern after 24 hours |Growth pattern after 48 hours | |L. acidophilus | Sediment |Sediment, mild turbidity and mild pellicle | |in liquid MRS broth | | | |S. epidermis | Nothing | Very mild pellicle | |in liquid nutrient broth | | |
I had growth after 24 hours in the L. acidophilus culture. There was only slight growth in the S. epidermis after 48 hours....