Is that water really safe to drink? Testing through the use of Coliscan EasyGel.
BY:
Crystal Meier
University of Wisconsin
River Falls
July, 2007
ACTIVITY DESCRIPTION:
This classroom ready project includes activities, laboratory exercise, instructional, materials, and evaluation methods for a study of biotechnology in water supplies. This project is designed so that it a five day unit on water quality and allowing the students to understanding their water supply. The water labs that are included are: Exploring the microorganism in water, purification, and Fecal Coliform Testing -- Using " Coliscan Easygel" Agar. Through this students will build skills on how to the water that they drink is safe and disinfected.
CLASS INTO WHICH PROJECT WILL FIT:
· 9-12 Wildlife Management
PART OF CLASS INTO WHICH PROJECT FITS:
These activities will fit into the course in course when talking about lake ecology. Being a wildlife management course it will fit into the course when we talk about pollution prevention and the relationships that exist in a water ecosystems. This unit will be related to water pollution, water filtration, and underground water. The unit is also related to environmental impacts that humans put onto an ecosystem. This unit will replace water pH tests and inorganic compound tests looking for water quality.
LENGTH OF ACTIVITY:
The length of these lessons can take up to five days as a unit. There are three distinct lessons, which include microorganisms in water, water pollution of bacteria, and purification of water.
Day 1: Introduction
Lecture: What is in water?
Activity: Slide discovery
Day 2: Bacterial contamination
Lecture: Introducing terms of water biology bacteria, E-coli etc.
Lab: Fecal Coliform Testing - Using " Coliscan Easygel" Agar
Day 3: Bacterial and Ecoli contamination in our water supply
Lecture: What can cause contamination?
Lab: Read Petri dishes Fecal Coliform Testing - Using " Coliscan Easygel" Agar
Day 4: Water Purification
Lecture: What makes potable water?
Lab: Set up of purification
Day 5: Wrap up
Lecture: Discussion of prevention bacterial overload
Lab read the lab results from purification
ALIGNMENT WITH STANDARDS
Wisconsin State standards that these activities address:
A.12.1 Apply the underlying themes of science to develop defensible visions of the future.
Students will develop an idea on how they have an impact on the future of the nation and world potable drinking supply. With this students will have understand how they can defend it.
B.12.3 Relate the major themes of science to human progress in understanding science and the world
Students will be able to see how water testing has improved the world around them. With expansions students can see the true affects of water borne diseases.
B.12.4 Show how basic research and applied research contribute to new discoveries, inventions, and applications
Students will create their own experiments through this learning process. With these application they will learn basic research and have applicable skills to apply it.
C.12.3 Evaluate* the data collected during an investigation*, critique the data-collection procedures and results, and suggest ways to make any needed improvements
Students will define results within the unit which they will need to compare their results to come up with a conclusion.
F.12.8 Using the science themes, infer changes in ecosystems prompted by the introduction of new species, environmental conditions, chemicals, and air, water, or earth pollution
Students will evaluate the affect of coliform bacteria on the environment and purpose ways to change their environment.
National Standards that these activities will address:
National Standard C: Sub- points
· Behavior of organisms
Students will evaluate the growth of bacteria. They will also explore microscopic organisms and evaluate the population size.
National Standard
CONTENT STANDARD E:
· Abilities of technological design
· Understandings about science and technology
Students will tackle this standard by trying experiments of their own. Students will also try high technology methods against traditional methods.
CONTENT STANDARD F:
· Personal and community health
· Population growth
· Natural resources
· Environmental quality
· Natural and human-induced hazards
· Science and technology in local, national, and global challenges
Student will evaluate the use of water from natural resources and see the affects that humans and other organism have on our water supply. They will evaluate ways to prevent water contamination. Students will also work towards being able to determine if water is safe or contaminated.
OUTLINE OF ACTIVITY:
Objectives and competencies:
Student will evaluate water quality quantitatively by checking sample for coliform growth.
Students will analyze water samples to see micro organisms that exist within a water sample.
Students will distinguish points of origin that bacteria can be increased from.
Students will create Easygel plates to distinguish the quality of water.
Student will deifier if water is potable.
Students will define water quality.
Concepts:
What lives in water
How does polluted water and clean water affect us?
Are bacteria harmful or helpful?
What is clean water?
What is pollution?
How do we as humans affect our environment?
Terms to be included:
Photosynthetic
Heterotrophic
Abiotic
Paramecia
Biodiversity
Coliform
Methane producers
BACKGROUND:
This unit is to get students to understand that they have an impact on the world around them. With the way that they dispose of waste can be harmful to themselves and other livestock. Through this unit students will be testing water samples to see if it is potable and healthy to drink. To achieve this objective, students will first identify the different types of bacteria and microorganisms that live within the water.
After students have accomplished an understanding of that water is not a pure substance they then will move into water quality and what water quality means. Students will discuss point and non point pollution and how this affects the water supply. Bacterial coliform will be stressed. Students will grow bacteria on plates and determine the safety of their water that they drink, swim, and boat in. Each of these has a different quota of bacteria that is allowable. For instance swimming has an allowable bacteria colony count of 20 fecal count (FC) per a 100 ml of solution. To calculate these allowable fecal counts you must take the number of colonies and divide them by 5 so that it is a 1:100 dilution.
To me able to teach this effectively students need to have background information in waterways and ecosystems. I have planned to put this unit as part of the water quality and have this after the water ecosystems. I have included background notes so that students develop an understanding of microorganisms. I planned for about a fifteen minute lecture and then to go get water samples near the school. If you do not have water ways near you, you may want to collect them earlier. I have read that micro-organism will die within six hour of being out their natural environment so you may want to factor for this.
There is further background information near each of the three labs which assist with learning and your background preparation for each lab. The supplies can come from numerous places as I was searching the most cost effective was Forestry Suppliers Inc. twenty test for 49.90 for the entire kit and replacement kits are 33.50. The website is http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=3786.
Day 1: Water Investigation
SPECIAL NEEDS ADJUSTMENTS:
For special needs adjustments I would have them only identify two strains. Also work with partners and only have to hand in one lab sheet with the group.
Interest generator: Have a sample of water.
What lives in this water?
Have students give you various responses.
Emphasize the thing that are really small and ask them about the things that they can not see with the naked eye.
Today we are going to look at water in a new way.
Lecture notes:
Microorganisms- organisms that are so small that they can not be seen with the naked eye.
Each microorganism is different.
Some are harmless and some like E-coli is harmful.
Ask students if they know what E-coli is?
Some of the different Microbe Characteristics
Photosynthetic- Able to get its energy from the sun
Heterotrophic- an organism that can not metabolize its own food and relies on organic complexes.
Abiotic- Non living factors of a ecosystem. Sunlight, temperature, atmosphere etc.
Paramecia- Fresh water microorganism that is usually oval shaped and a groove for feeding.
Biodiversity- Number and variety of organism growing in one area.
Coliform- bacteria that inhabits colon of humans or other animals
Methane producers- bacteria that produce a methane by-product.
EXERCISES TO BE INCLUDED:
Materials Needed
3 sterile containers per a group
3 slides per a group
1 microscope per a group
1 worksheet packet per a person
Your Task:
1) Partner up with someone
2) Collect three water samples in sterile containers
3) Go back to class when everyone has there sample.
4) Prepare a wet mount
- Get three slides
- Extract .5 ml of water with a bulb dropper
- Place a cap under it
5) Place the wet mount under the microscope
6) Record your findings on the worksheet attached
EVALUATION: Lab write up
1. Identify 5 different types of organisms that you have found based on the information pages.
2. Which organisms seem to be most abundant?
3. Of those organisms found, name those that are photosynthetic.
4. Name those that are heterotrophic.
5. Name some abiotic factors affecting the populations of microorganisms.
6. Predict a possible outcome resulting from an increase in the population of Paramecia.
7. Draw some conclusions about the biodiversity of the pond ecosystem.
Information Page
Types of Algae
Star Filament Algae Fluorescing
Kingdom: Protist
Scientific Name: Zygenema
Image Courtesy of: Shirley Owens
Image Width: 45 microns
Image Technology: Laser Scanning Confocal Microscopy
This is a type of algae that lives in ponds. Algae are protists that have chlorophyll, like plants do, and are thus able to make food for themselves using sunlight via photosynthesis. Many algae, such as this one, grow in long strands of individual cells strung end to end. This image shows several cells in a portion of such a strand. This image does not show the whole algal cells, but instead highlights a part of the internal structure of the algae, their chloroplasts.
This image was created using fluorescence. The algae were originally illuminated with light of a relatively short wavelength, chosen specifically because chlorophyll absorbs light at that wavelength. The chlorophyll re-emits, or fluoresces, the light energy at a longer wavelength. Since the chlorophyll in algae is gathered in its chloroplasts, it is the chloroplasts inside the algal cells that we see in this view.
Diatom
Kingdom: Protist
Scientific Name: Diatom
Image Courtesy of: Joanne Whallon
Image Width: 15 microns
Image Technology: SEM (Scanning Electron Microscope)
The large, round object in the center of this view is a diatom. Diatoms are protists that grow a silica shell around themselves. When diatoms divide, each offspring takes half of the original shell with it, and grows another matching half to complement the inherited shell portion. Diatoms are frequently found in wet environments, such as ponds. They also grow on most soil. Diatoms grow on the surface layer of soil, where they can use sunlight to produce food via photosynthesis. This species of diatom is yellow-brown in color when viewed with visible light. There are two basic types of diatoms: elongate ones and round ones, like this microbe. Elongated diatoms can move themselves about; round diatoms cannot. There may be as many as 10,000 species of diatoms. Huge accumulations of fossilized diatoms make up diatomaceous earth, which is used in toothpaste and in filters.
Mummy-shaped diatoms
Kingdom: Protist
Scientific Name: Hemitrichia serpula
Image Courtesy of: Shirley Owens, Center for Electron Optics, Michigan State University
Image Width: 36 microns
Image Technology: SEM (Scanning Electron Microscope)
The large creatures in this image that look like mummy cases are diatoms. Diatoms are protists that grow a silica shell around themselves. When diatoms divide, each offspring takes half of the original shell with it, and grows another matching half to complement the inherited shell portion.
These diatoms are shown here growing on duckweed plants found in a pond. The smaller creatures around the diatoms are various species of bacteria. Diatoms are frequently found in wet environments.
Diatoms also grow on most soil. They grow on the surface layer of soil, where they can use sunlight to produce food via photosynthesis.
There are two basic types of diatoms: round ones and elongated ones, like these. Elongated diatoms can move themselves about; round diatoms cannot.
There may be as many as 10,000 species of diatoms. Huge accumulations of fossilized diatoms make up diatomaceous earth, which is used in toothpaste and in filters.
Types of Cyanobacteria
Blue green photosynthetic bacteria are called cyanobacteria. These were formerly thought to be algae, until scientists found that they had no nuclei, like other bacteria. Close relatives of cyanobacteria were probably the ancestors of the photosynthetic organelles (plastids) in modern plants.
Gloeocapsa
/ Kingdom: EubacteriaScientific Name: Gloeocapsa
Image Courtesy of: Whallon, Joanne
Image Width: 7 microns
Image Technology: Laser Scanning Confocal Microscopy
This photosynthetic bacterium belongs to a group of bacteria known as a cyanobacteria. Many of these organisms live in ponds. Gleocapsa is a genus name which includes the species gleocapsa and chroococcus. The picture of this microbe may be misleading to your senses. Although this image looks like several fried eggs on a griddle, the organism is actually spherical, with six dark central spheres inside of six additional spheres that cannot be seen. This image, like others in the Microbe Zoo, must be interpreted by you, the scientist. Many times, your brain will have to do some mental morphing to make more accurate models of how microbes actually are in nature. No imaging technique is perfect. Often times, many different imaging techniques must be used to properly interpret the true structure of a microbe.