UNIT TASK11-Identification of Enterobacteriaceae-Biochemical Testing PDF

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LABORATORYOur Lady of Fatima UniversityCollege of Medical Laboratory ScienceSecond Semester SY 2020-UNIT TASK#11: Identification of Enterobacteriaceae:Biochemical TestingChristian Nestel L. Bucayu Deadline: April 21, 2021BSMT 2-Y2-Critical Thinking Questions:Answer the following. Submit it on a .doc...

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LABORATORY Our Lady of Fatima University College of Medical Laboratory Science Second Semester SY 2020-2021 UNIT TASK#11: Identification of Enterobacteriaceae: Biochemical Testing Christian Nestel L. Bucayu 2021

Deadline: April 21,

BSMT 2-Y2-3 Critical Thinking Questions: Answer the following. Submit it on a .docx document. 1. Give the importance of carbohydrate fermentation test. (5 pts) 2. Give the different bacterial enzymes involve in the fermentation of sugar. (5 pts) 3. Discuss how some bacteria are able to produce the black precipitate on TSI Agar slant. (10 pts)

Critical Thinking Questions: Answer the following. Submit it on a .docx document. 1. Give the importance of carbohydrate fermentation test. (5 pts) The aim of a carbohydrate fermentation test is to determine whether or not a particular bacteria or microorganism is capable of fermenting a specific carbohydrate. It can also be used to distinguish between various bacterial genera or groups based on carbohydrate fermentation results or patterns. As well, this test can also detect the presence of acid, gas, and H2S production during the fermentation of a particular carbohydrate. In addition, these fermenting bacteria are typically facultative anaerobes. 2. Give the different bacterial enzymes involve in the fermentation of sugar. (5 pts) In order to ferment specific carbohydrate, bacteria are containing bacterial enzyme that degrades these sugars. Permease and betagalactosidase are two examples of the bacterial enzymes involved in carbohydrate fermentation. Permease is an enzyme that allows lactose to pass through the bacterial cell wall, wherein beta-galactosidase is degraded into glucose and galactose. Permease is present in bacteria such as E.coli, Klebsiella and Enterobacter which considered as rapid lactose fermenters. Wherein beta-galactosidase are present in E.coli and Citrobacter spp. The protease enzyme is also involved in the sugar fermentation process. Proteolytic bacteria used this enzyme to break down undigested peptides, which are then used in proteolytic fermentation. Also, bacteria that produce enzyme as they ferment carbohydrates produces amylase, which is critical in the production of products in the industry. It is an enzyme that is in responsible for degrading starch into sugar. 3. Discuss how some bacteria are able to produce the black precipitate on TSI Agar slant. (10 pts) Some bacteria are capable of reducing sulfur, and the resulting H2S (Hydrogen Sulfide) gas reacts with iron salts to form iron sulfide, which then forms a black precipitate in the agar slant. The butt part of the tube blackens

as a result of the H2S reaction, which releases acid. To summarize, some fermentation may result in not only acids but also black precipitation. Hydrogen sulfide production are detected by blackening of the agar. As we observe, the slanted part of the media is to determine whether the organism fermented two to three sugars or carbohydrates or only glucose is fermented or if there are no sugar fermented. H2S producing bacteria are Salmonella, Proteus mirabilis, Citrobacter freundii, and Edwardsiella species. Usually, the blackening of the medium is observed in the butted part of the tube....