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How Bacteria Can Be Differentiated With Specific Metabolic Activities

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Introduction
Bacteria can be differentiated with specific metabolic activities. There are a variety of reagents and methods that can be used to distinguish species. The purpose of this experiment was to determine the characteristics of four different bacteria through four unique tests. The bacteria tested include: Escherichia coli (Ec), Pseudomonas aeruginosa (Pa), Bacillus subtilis (Bs) and Proteus vulgaris (Pv). Four types of tests were performed to understand the metabolic activities of the four bacteria.
The first test executed was the fermentation of carbohydrates. The objective of this particular test is to identify the ability of microorganisms to ferment a specific carbohydrate (Reiner, 2012). The test can be used to identify three different ways in which bacteria can ferment simple carbohydrates. Bacteria can be tested for acidity, alkalinity, whether or not it remains neutral and gas formation (Reiner, 2012). To conduct the carbohydrate fermentation test, a pH indicator, bromocresol purple, is used to indicate an acidic characteristic (Reiner, 2012). Bromocrescol purple indicates carbohydrate fermentation media by turning a deep purple if it’s an uninoculated media, yellow if it’s acidic and purple if it’s alkaline (Reiner, 2012). Durham tubes are placed inside the tubes containing the media and bacteria to detect gas production (Reiner, 2012). Three different carbohydrates were tested for fermentation during this test: glucose, sucrose and lactose for each of the

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