Unknown Lab Report

Unknown Lab Report
Unknown # 25
By: Jenna Riordan
March 19, 2018
Bio 2843

1. Introduction Microbiology is the study of microorganisms found in all different environments throughout Earth, from the hot thermal vents at the bottom of the ocean to the ice at the top of a mountain. These microorganisms are used to teach us how multicellular organisms came to be and how they can survive today. These small, microscopic organisms are so unique that the identification of them is paramount in the advancements of science. Knowing the chemical makeup, the shape, and the biochemical processes is important in identifying these organisms to understand how they survive and where. A number of tests can be ran on an unknown bacteria to determine their ideal

Crystal violet was then added for 60 seconds before being washed off with water. The mordant, Gram’s Iodine, was added for another 60 seconds before getting washed off with water. The heat fixed smear was then washed with 95% alcohol until the wash ran clear, leading to the final step of adding Safranin for 45 seconds before being rinsed with water. The slide was finally blot dyed with bibulous paper before it was placed under a microscope to observe the color and shape of the bacterium.

2.2 Litmus Milk Reaction
A milk-based, litmus broth tube is incubated and observed after 48 hours. Observations include lactose fermentation without gas as well as with gas, the reduction of litmus, casein protein coagulation and casein and protein hydrolysis. These characteristics were all determined based on the color of the solution and the production of a curd, the curds density and the production of a gas. To determine the density of the curd, the tube was slightly turned to see rather or not it was mobile or concentrated towards the bottom.

2.3 Carbohydrate Fermentation of Lactose, Sucrose and

The tube was placed back in incubation for 96 more hours to observe any more positives.

2.10 Catalase Test
A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed.

2.11 Starch Hydrolysis
A starch agar plate was inoculated with a streak of the unknown bacteria and then incubated. On the second day of incubation, the plate was removed from the incubator and placed over a hot plate heating Iodine solids. The smoke of the Iodine stained the plate to display the presence or absence of a halo around the bacteria

2.12 Lipid Hydrolysis
This test was done by making a single line streak inoculation on a tributyrin agar plate and allowing incubation. After the incubation period, the plate was observed for the presence or absence of a halo around the bacteria.

2.13 Gelatin Liquefaction
A gelatin deep was deep stabbed and incubated. After incubation the tubes were placed in 4ºC for 30 minutes. The cultures were then examined to determine if gelatinase was solid or liquified

2.14 Oxidase