Lab quiz 2

Why is TSI inoculated the way it is?

To put bacteria into aerobic conditions(slant) and make anaerobic conditions(butts)

What is the name given to the small, inverted tube often put into sugar fermentation and what’s its purpose?

It is a durham tube, and it collets gas

What sugar fermentation does the butt of TSI agar show?

Glucose

What is the appearance of a sucrose and glucose fermenting organism with TSI agar?

Both the slant and butt are yellow

What does TSI stand for?

Triple sugar iron

What sugar(s) fermentation can the slant of TSI show?

Lactose and sucrose

What is often added to media that reacts with sulfur to produce a black color/precipitate?

Iron

How is TSI agar inoculated and with what tool?

Stab down into the butt with a needle, and streak along the slant after you pull needle straight out w/o wiggling

What is the appearance of a gas and sulfur producing glucose fermenter with TSI agar?

The butt will be black, yellow, and cracked. The slant will be pink/orange-ish

Why is TSI inoculated the way it is?

To put bacteria in aerobic and anaerobic environments.

What sugar fermentation does the butt of TSI agar show?

Glucose

What is the appearance of a gas and sulfur producing glucose fermenter with TSI agar?

Butt will be yellow, black, and cracked. Slant will be yellow.

Why does TSI show different sugar fermentation in the butt of the agar than it shows in the slant?

When glucose is exposed to the media onto the slant, it will be used up quickly because an aerobic slant has a much fast growth rate(exposed to more oxygen). Anaerobic growth rates are a lot slower, so it is more likely that a different sugar would ferment rather than glucose.