Coliforms are used as indicator organisms of sewage pollution because
a. they are pathogens.
b. they ferment lactose.
c. they are abundant in human intestines.
d. they grow within 48 hours.
e. all of the above

It is possible to purchase the following microorganisms in a retail store. Provide a reason for buying each.

a. Bacillus thuringiensis

b. Saccharomyces

NAME IT These organisms are important in sewage treatment and can produce a fuel used for home heating and for generating electricity.

Which of the following is an example of bioremediation?

a. application of oil-degrading bacteria to an oil spill

b. application of bacteria to a crop to prevent frost damage

c. fixation of gaseous nitrogen into usable nitrogen

d. production by bacteria of a human protein such as interferon

e. all of the above

Bioremediation refers to the use of living organisms to remove pollutants. Describe three examples of bioremediation.

What is industrial microbiology? Why is it important?

DRAW IT Identify where the following processes occur: ammonification, decomposition, denitrification, nitrification, nitrogen fixation. Name at least one organism responsible for each process.

<IMAGE>

Potable water is allowed to have ________coliforms per 100 ml of water tested.

Nitrification converts _____.

a. organic nitrogen to NH3

b. NH3 to NH4+

c. NH4+ or NH3 to NO3

d. NO3 to N2