Sauerkraut Lab #4

How many ATP during Lactic Acid Fermentation?

...

How many ATP are produced in glycolysis?

4 are formed, but 2 are used during glycolysis reactions, so net gain is 2.

What are two genera of bacteria that produce endospores?

Bacillus and Clostridium

What are some diseases associated with bacteria that produce endospores?

Bacillus anthracis causes anthrax Clostridium tetani cause tetanus

What is considered a *countable number* when doing a *standard* plate count?

Between 30-300 bacterial colonies

What are the reactants and products of glycolysis?

C6H12O6 + 2NAD+ + 2ATP → 2 Pyruvate + 2 NADH + 4ATP

Purpose of adding salt to the cabbage preparation

It kills the bacteria and draws water out of the cabbage

What happens to pH as the experiment progresses? Why?

It will go down over time. Bacteria that produce lactic acid naturally lower the pH.

What is a hemocymeter?

Special slide used when doing a direct microscopic count.

What is the spread plate method?

Spreading of liquid bacteria so they are easier to count and isolate

Two ways to determine the concentration of bacteria in a solution.

Standard Plate Count or Direct Microscopic Count

What is the purpose of lactic acid fermentation?

This process regenerates NAD+ so that glycolysis can continue

What happens if too much salt or too little?

Too much will kill ALL the bacteria, even the good ones. Too little and bacteria will multiply.

What is the disadvantage of direct microscopic count?

You can't tell which cells are dead vs alive

Wild fermentation

You don't start with a "starter culture"

How to determine the serial dilutions of different tube and plate scenarios

You multiply the original concentration by the dilution factors for each dilution

What is the advantage of standard plate count?

allows counting of live cells

What are endospores?

survival structures that resists adverse environmental conditions