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Isolation of Bacteria

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Isolation of Bacteria
Isolation and identification of an unknown bacterium
Pillay, Esmerelda (209504371)
School of Biochemistry, Genetics and Microbiology
Department of Microbiology
University of Kwa-zulu Natal
25 October 2010

ABSTRACT

Different types of bacteria in various forms are found all around us, and it is a microbiologist’s job to be able to identify these bacteria. Using various staining techniques and physiological tests, an isolated bacterium can be identified. In this experiment, a single bacterial colony was isolated form Mycorrhizal spores, and further tests done on that colony. Sub culturing was done after each week to ensure that the bacterium has sufficient nutrients required for optimum growth that will last the duration of the entire experiment. A flow chart was created based on the results of the physiological tests in order to identify the isolated bacterium. After 4 weeks, the isolated bacterium was identified as XXXXX for reasons stated in the results and discussion.

INTRODUCTION

The main goal of this experiment was to identify the isolated bacterium that was obtained from Mycorrhizal spores. In order to identify the bacterium, the experiment was conducted in 4 parts: (a) isolation of an unknown bacterium from soil; (b) identification of the bacterium using various staining techniques; (c) determining the motility of the bacterium; and (d) determining the physiological characteristics of the bacterium.

Part (a) of the experiment involves isolating a single bacterial colony from the culture. The remaining 3 parts will be conducted on that colony. In part (b), it is shown that various staining techniques test for different characteristics. As the name suggests, a gram stain is conducted to identify the bacteria as gram negative or gram positive. Two other stains were carried out. To determine the motility of the bacterium, wet mounts of the bacterium were observed and the motility was confirmed by using soft agar plates and soft agar deeps for



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