Unknown Lab Report Essay

The goal of this experiment was to identify as well as learn about an unknown species of bacteria along with learning some techniques when it comes to process of elimination in a scientific study. To do this, many different tests were completed to help rule out species that were provided on a sheet of paper listing the possible candidates for the unknown microbe. The Bergey’s Manual of Determinative Bacteriology flow chart was also used to narrow down choices as tests were completed, along with a flowsheet of gram positive and negative microbes provided in Microbiology Class. To begin the process of identifying unknown microbe #7, two isolation streaks of the mystery microbe were made in order to determine whether the microbe likes to grow at 30˚C or 37˚C. It was discovered that the microbe likes to grow more at 37˚C. Next, an observation under the microscope as well as a gram stain were conducted. These tests were conducted in order to identify and understand the shape of the microbe and if it was gram …show more content…
Using the results from the sucrose test, Corynebacterium bovis could be eliminated because it’s test for sucrose was negative and unknown microbe #7 was positive for sucrose. Lastly, using the results from the glucose test as well as the methyl-red test, which helped identify which fermentation pathway was being used: the acid fermentation pathway or butanediol pathway, unknown microbe #7 was finally identified. After testing for methyl-red, it was concluded that unknown microbe #7 was Corynebacterium xerosis because the glucose test for Corynebacterium pseudodiphtheriticum was negative, meaning the microbe didn’t ferment glucose, and unknown microbe #7 did ferment