Oxidation and fermentation test Please write a summary and conclusion for the la
ID: 261575 • Letter: O
Question
Oxidation and fermentation test
Please write a summary and conclusion for the lab results
L OFI Sugar Fermentation Bacteria II. Sugar Fermentation Nitrate Siummons gar TIrspticass Glucose citrate slant (oxidase) slant R-VP (catalase) Lactose Mannitol Glucose broth broth broth Acid&Acid; &Acid; &Positive; Staphylococcus Non oxidative EscherichiaNon oxidative Enterobacter Non oxidative Acid & Acid & Acid & Negative Pseudomonas Non oxidative Acid & Acid & Acid & Positive Unknown A Non oxidative Acid & Acid & Acid & Positive Positive Positive Positive Positive Positive NegativePositive Positive Positive Negative Positive Positive Positive Positive Positive Positive Positive Positive Positive Positive aureus gas as Acid &Acid;& Acid &Negative; coli gas gas gas aerogenes as gas gas aeruginosa gas gas gas gas gas gas ??? acerExplanation / Answer
All the bacterial species including unknown A are fermentative in nature which means they cannot oxidise the glucose to carbon dioxide through oxidative metabolism. Rather they ferment the sugar without using oxygen. But all the sugar molecules cannot be fermented by bacteria, herein production of acid and gas in the broths of lactose, mannitol and glucose indicates that all these sugar molecules can be fermented by all the bacterial species. Methyl Red-Voges Proskauer (MR-VP) is a test to identify the ability of an enteric bacteria to ferment glucose into an acidic product. Staphylococcus aureus, Pseudomonas aeruginosa and Unknown A are positive for MR-VP test as all these can ferments glucose into acidic product whereas E.coli and Enterobacter aerogenes are negative for MR-VP test. Nitrate broth test is to test the ability of bacteria to reduce nitrate into nitrite using enzyme nitrate reductase. Basically it tests whether bacteria has an enzyme nitrate reductase or not. Positive result for all bacteria indicates that all these have nitrate reductase enzyme. Simmon's citrate test is to differentiate Gram-negative bacteria based on their abillity to use citrate as a carbon source. Staphylococcus aureus, Pseudomonas aeruginosa and Unknown A are positive in nature while E.coli and Enterobacter aerogenes cannot able to use citrate as a carbon source. Agar slant test is to test whether bacteria produces catalase enzyme or not. Catalase enzyme breaks down hydrogen peroxide into water. Positve result indicates that all these bacteria are capable of degrading hydrogen peroxide. Trypticase (oxidase) test is to identify whether bacteria has an enzyme cytochrome oxidase and are able to mediate trasnfer of electron between electron donars. Result column shows all the bacteria are positive for this test. However, enteric bacteria should show negative result for this test, for example E.coli.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.