Depletion Of The Reducing Agent Of Sodium Tioglycolates

An unknown bacterium was handed out by Dr. Honer. The appropriate tests were prepared and applied. The first procedure that was done was the gram stain. Under a microscope, if the gram stain is purple, the bacterium is gram positive, if the stain is red, it is gram negative. The next test was the fermentation tests for glucose, sucrose and

This experiment was centered on metabolic and biochemical testing procedures. The rationale of performing these tests was to distinguish six different microbes from one another and to compare how their metabolic and biochemical processes differ from species to species to determine the unknown sample.

I identified Citrobacter freundii, the gram negative rod, by running a series of tests. I began with the Phenol Red Lactose tests, which tests if the organism contains various enzymes that determine if it can ferment lactose. The broth turned yellow after it was incubated, indicating that the lactose was fermented to acid, and there was also gas present in the Durham tube. Since the Phenol Red Lactose Test was positive, I then ran the Phenol Red Sucrose test, which tests if the bacteria contain different enzymes that determine if sucrose can be fermented. After incubation, the broth was yellow, indicating that sugar was fermented to acid, and there was also gas present in the Durham tube. Next, I ran the Sulfide Production, Indole Formation, Motility test, but I was only testing for Hydrogen Sulfide Production to differentiate between the organisms Citrobacter freundii and Enterobacter aerogenes. This test detects if the organisms can metabolize sulfur into hydrogen sulfide, which is revealed by the formation of ferrous sulfide that causes blackening around the growth. The test also reveals if the organism can break tryptophan into indole or migrate away from initial stab area. After incubation, the agar slant was completely black, indicating that the organism produces hydrogen sulfide and is motile proving that it was Citrobacter

The conditions needed for the growth of micro-organisms are: Micro - organisms need food to survive. They like high protein food to survive, eg. Poultry & fish. Most micro - organisms need warmth & grow best at 20-40c. They need moisture to multiply. They need air to multiply, though some can without. A single Micro-organism becomes two every twenty minutes.

This test is used to detect if the bacteria contains any deoxyribonuclease activity. Because no color change was observed from blue to clear my unknown bacteria displayed a negative result.

Why or why not? Different types of bacteria are rubbed on each side of a petri dish. If there is more bacteria put on one side that side is going to grow more. Just because they are in the same petri dish doesn’t mean that they

An Aerotolerant Anaerobe- can grow in oxygen if present, but does not use oxygen. If it was in a test tube there would be equal growth throughout the broth, While a Facilitated Anaerobe uses oxygen, it can grow without it. In a test tube there would be more growth at the top of the broth that anywhere else.

The purpose of this investigation is to discover the effect of pH on the activity of catalase, an enzyme which plays the integral role of converting hydrogen peroxide into water and oxygen, and discover which pH level it will work at the most efficient rate (the optimum). The original hypothesis states that that the optimum would be at a pH is 7, due to the liver, where catalase usually resides, being neutral. The experiment consists of introducing the catalase to hydrogen peroxide, after exposure to certain solutions; hydrogen peroxide, water and hydrochloric acids, all containing the adjusted pH, and measuring the height of froth formed, an observable representation of the activity of the enzyme. The final data indicated that

In order for growth to occur microorganisms need to obtain energy. One of those ways is by either the use of oxygen or not using oxygen. Microorganisms that require oxygen are obligate aerobes. It is essential for

The bacteria in Tube D were able to increase their population size for a longer amount of time than the bacteria in the other tubes because the limiting nutrient ran out quicker in the other tubes than in Tube D. Conversely, Tube A had the smallest absorbance value and was not supplied with any glucose. The bacteria in Tube A were only able to grow minimally without glucose. The generation time of the tube with more glucose was quicker than the generation time of the other tubes because the increased availability of glucose allowed the bacteria to divide more. The bacteria in Tube D were able to divide for a longer period of time because their limiting nutrient was present for a longer amount of time.

An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolize substances, like sugars or fats, to obtain energy.

They are non-spore shaping, non-motile and facultative anaerobes and create by vigorous breath or by aging. They are both catalase-coagulase positive and oxidase negative (Middleton, 2013).

Bacillus species can be obligate aerobes (oxygen reliant),or facultative anaerobes.They will test positive for the enzymecatalase when there has been oxygen used or present. And

This experiment is designed to analyze how the enzyme catalase activity is affected by the pH levels. The experiment has also been designed to outline all of the directions and the ways by which the observation can be made clearly and accurately. Yeast, will be used as the enzyme and hydrogen peroxide will be used as a substrate. This experiment will be used to determine the effects of the concentration of the hydrogen peroxide versus the rate of reaction of the enzyme catalase.

With the results of the Starch Hydrolysis Test I preceded to the final test which is the Citrate Test. Using aseptic technique, I streaked the organism onto the surface of the Simmons’ citrate slant and let it incubate overnight at 37°C. The Citrate Test determines if the organism is able to