Microbiology Lecture Notes

These flashcards cover key concepts related to exoenzymes, biochemical tests, and microbial characteristics as outlined in the lecture notes.

What are exoenzymes?

Exoenzymes are enzymes that are secreted by microorganisms to break down complex molecules outside their cell.

What is indicated by a positive clearing on a starch plate?

A positive clearing indicates the presence of starch-digesting enzymes, such as amylase.

What is the role of mylase enzyme?

Mylase (or amylase) enzyme catalyzes the hydrolysis of starch into sugars.

What does 'DNGS' refer to in microbiological tests?

DNGS refers to a specific biochemical indicator or test, the full meaning may depend on context.

What does a green plate indicate in enzyme tests?

A green plate indicates a specific result, often linked to the activity of enzymes or pigments produced by microbes.

What is an opportunistic pathogen?

An opportunistic pathogen is a microorganism that can cause disease when the host's immunity is compromised.

Define transient pathogens.

Transient pathogens are microorganisms that are easily transferred from one host to another but do not usually cause disease.

What does a yellow phenol red tube indicate in biochemical testing?

A yellow phenol red tube indicates the production of acidic products from fermentation, such as lactose.

What does sulfur reduction in media indicate?

Black coloration in the media indicates sulfur reduction by microorganisms.

What indicates gas production in biochemical tests?

Gas production is usually indicated by bubbles or displacement in the medium.

What does pink coloration in protein digestion tests signify?

Pink coloration indicates that protein digestion has occurred.

What is indole production and how is it identified?

Indole production is identified by a red/green color change after adding Kovac's reagent.

What does yellow indicate in motility testing?

Yellow indicates a negative result for motility in media.

What does a stab line indicate in a motility test?

A stab line indicates the path taken by the inoculum; growth away from the stab line indicates motility.

What is the significance of alkaline and product red in bacterial tests?

Alkaline and product red indicate the presence of specific metabolic products, often related to fermentation.

What type of pathway did the vague proshur-photolyn pathway reference in testing?

It refers to a metabolic pathway utilized by certain bacteria for energy production, possibly related to photosynthesis.

What is urea's role in biochemical tests?

Urea in tests helps determine the ability of bacteria to hydrolyze urea, changing the medium to pink if positive.

What does citrate blue indicate in microbiology?

Citrate blue indicates that a microorganism can utilize citrate as its sole carbon source.