Apes Fecal matter

What bacteria makes up over 80-95% of the bacteria found in the feces of humans?

Escherichia coli or E. coli for short.

What is the overall shape of coliform bacteria?

rod shaped

What does it mean when we say that fecal coliform are indicator organisms?

It means that they can indicate that sewage is present in a body of water. If sewage is present, then – it means that it is likely that pathogenic bacteria can be found as well.

Why are fecal coliform bacteria used as indicators of sewage entering a body of water?

They are much more abundant and easier to test for than the pathogens that might be in the sewage.

How abundant are pathogens in most bodies of water.

They are relatively scarce.

What are fecal coliform?

They are bacteria that live in the intestines of warm-blooded organisms.

What do we call bacteria that can live without oxygen?

Anaerobic bacteria

What do we call bacteria which require oxygen to carry on their life functions?

Anaerobic bacteria

What is nonpoint pollution?

This type of pollution cannot be traced to a single site, such as an outlet or pipe, because it comes from many individual places or a widespread area (typically urban, rural, and agricultural runoff, acid mine drainage, etc.).

What can an increase in the number of fecal coliform indicate?

It typically can indicate a decrease in the overall water quality of a body of water.

Swimming is not allowed in bodies of water when the fecal coliform level exceeds how many colonies?

200 fecal coliform colonies per 100 mL of water.

What method did we use to sample for fecal coliform?

The Coliscan Easygel EZ Method.

Where should a proper sample for fecal coliform be taken within a river?

Beneath the surface and in the current.

What are some diseases you can get from water contaminated with sewage?

Cholera, typhoid fever, diarrhea, etc.

What is a petri dish?

A piece of laboratory equipment (glass or plastic) used to culture (grow) bacteria.

How are Petri dishes incubated?

Inverted or upside down.

What does it mean to use sterile technique?

This technique must be employed when culturing bacteria in order to do it safely and to be certain you only culture the bacteria you are trying to grow.

What is nutrient broth?

What is used to nourish bacteria during culturing. It provides nutrients and food for the fecal coliform bacteria.

Choosing the correct volume of water to sample when doing the fecal coliform test is very important. When the experiment is done correctly, approximately how many fecal coliform colonies will be present?

20 to 60 colonies.

If there are more than ___ colonies of one color, the result should be recorded as “Too Numerous To Count (TNTC)”?

300

What federal agency is typically responsible for managing water quality in the United States?

The Environmental Protection Agency or EPA.

Direct discharges of organic wastes like sewage in water has been a much rarer occurrence because of the passage of what law? What important federal law was passed that has led to much needed improvement in the way we treat our nation’s waterways?

clean water act

How many fecal coliform colonies can drinking water contain?

0 total coliform colonies per 100 mL of water.

What is the most important information that should be included somewhere on the Petri dish (where it doesn’t obscure the colonies you will need to count)?

The date, site, volume tested, team number, and initials of group members.

What is the proper way to dispose of living or viable microbes?

Pour bleach into the Petri dish and dispose of it in the trash.

What are some safety precautions you should use before and after testing for fecal coliform?

Wash your hands before and after performing tests, do not eat or drink during testing and cleanup, and wipe tables with disinfectant.

What should you never do when working in lab with chemicals or bacteria?

Rub your eyes and nose using your hands.

How many coliform colonies can drinking water have?

0 total coliform colonies per 100 mL of water.

When sampling for fecal coliform it is important that the water sample be tested how soon after collection?

It should be tested within an hour of collection unless it is put on ice or refrigerated.

For the purposes of the Friends of the Rouge River Water Quality Monitoring Project, we report the results in terms of?

Fecal coliform per 100 mL of water.

Which colonies are counted in the petri dish?

Those growing on the surface of growth medium and within it.

How many people should count the colonies on a Petri dish?

It is best if several people verify the bacterial count.

If several people do the fecal coliform test, each reporting different numbers of colonies, what result should be reported?

The highest number of colonies.

When incubating the fecal coliform at room temperature, what is the ideal time they should be incubated?

48 hours

To determine the E. coli or fecal coliform, what color colonies did you count?

dark blue-purple

In the past, the Rouge River has often had unusually high fecal coliform readings after periods of heavy rain. Why was this?

We have a combined storm and sanitary sewer system that was overloaded during heavy rainfalls and raw sewage was allowed to spill directly into the river rather than overload the wastewater treatment plant.

What is one of the solutions that Dearborn Heights has implemented to help cut down on the amount of sewage that enters the Rouge River on a yearly basis?

We’ve built a series of underground water retention basins.

When are fecal coliform generally more abundant in waters of the Middle Branch of the Rouge River that we monitor?

After periods of substantial rainfall.

If you are testing water from a well thought to be relatively free of bacteria – would you choose a large amount of water to test or a small amount?

Large Amount

If you suspected raw sewage was in a sample of water you were testing – would you choose a small amount of water to test or a small amount?

Very small amount

What device is typically used to transfer precisely measured volumes of water into the testing broth?

Dropping pipette.

One you place the water you are testing into the nutrient broth, how long do you have to before it should be put into the Petri dish.

Once the nutrient broth and the water being tested are mixed, you should wait no longer than 10 minutes before pouring it into the Petri dish.