Using Indicator Bacteria to Monitor Public Water Supplies

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Emerging Diseases Linked to Environmental Change

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:07 The Benefits of Bacteria
  • 1:11 Indicators Warn Us
  • 2:39 Harmful Indicator Bacteria
  • 3:26 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Lesson Transcript
Instructor: Sarah Friedl

Sarah has two Master's, one in Zoology and one in GIS, a Bachelor's in Biology, and has taught college level Physical Science and Biology.

In this video lesson, you will learn about indicator bacteria. You will understand how and why they are used to test for water contamination despite the fact that they are harmless and naturally occurring in human and animal systems.

The Benefits of Bacteria

Bacteria sure do get a bad rap! Anti-bacterial hand cleaners, antibiotics, and other treatments are all designed to get rid of these microscopic organisms that come in all shapes and colors.

But actually, most bacteria are either harmless or beneficial to you! Just to name a few ways they help, beneficial bacteria keep harmful agents from getting through your skin to other organs, digest food in your stomach and intestines, help you absorb vitamins and minerals from your food, break down dangerous substances that get in your body, and fight disease.

E. coli is one such beneficial bacterium. E. coli is found in your colon, and it helps you absorb nutrients from your digested food that you can't take up on your own.

E. coli is just one of many indicator bacteria, which tell us if fecal contamination has occurred in a water supply. Indicator bacteria are for the most part harmless, but we test for them because if contamination has occurred, there is a good chance that bacteria that are harmful are present in the water supply as well.

Indicators Warn Us

There are many different types of indicator bacteria. We've already talked about E. coli, which lives in your colon. Others include the total coliforms, fecal coliforms, fecal streptococci, and enterococci.

These occur naturally in many animals and humans, and as mentioned before, they serve beneficial roles for us. Because they live in your gut, they often come out with fecal matter, so you can tell if fecal matter has gotten into the water supply by testing for these indicator bacteria.

However, fecal matter may also contain other harmful bacteria and pathogens. Typhoid fever, giardia, salmonella, and hepatitis A are all waterborne diseases, which means they travel through water bodies. These are harmful to both humans and animals and thrive in the same environment as the harmless indicator bacteria - your gut! So, if indicator bacteria are present, there's a good chance that other, more harmful bacteria are as well.

So, why not just test for the harmful bacteria? Indicator bacteria are used because they are more easily identifiable, tend to occur in larger numbers, and come from specific sources. However, just because indicator bacteria are present doesn't necessarily mean that harmful bacteria are as well. It just tells us that we need to look more closely at the contaminated water supply to identify possible harmful agents that may also be present, since they thrive in the same environments.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account
Support