Lec 13 + 14 Fermentation and Metabolism in Identification

Which of the following is a typical characteristic of a fermenter?

Lacks genes for Krebs cycle or ETC components

What is the main purpose of converting pyruvate to lactic acid in homolactic fermentation?

To regenerate NAD⁺ for glycolysis and allow continued ATP production

In alcohol fermentation, what is reduced to regenerate NAD⁺?

Acetaldehyde

Why is phospholipase production considered a virulence factor?

It breaks down host cell membranes, aiding infection

Why is the Krebs Cycle considered amphibolic

Its intermediates can be used in both anabolic and catabolic reactions

Which of the following can be products from Krebs cycle intermediates?

Amino acids, nucleotides, fatty acids

What does the IMViC panel test for?

Biochemical characteristics of coliform bacteria (e.g., indole, MR, VP, citrate)

What does a positive methyl red (MR) test indicate?

Mixed acid fermentation (heterolactic

What does a positive catalase test suggest about a microbe?

It performs aerobic respiration and breaks down hydrogen peroxide

What does a positive oxidase test indicate?

The presence of cytochrome c in the electron transport chain

What does a positive nitrate reduction test suggest?

The organism can perform anaerobic respiration