The effects of Roundup on Euglena gracilis

Henry R. Walther Grade 10

Pittsburgh Central Catholic High School

Surface Runoff Water that flows over the

land surface and is a component of the water cycle

Many substances from our technology can dissolve in water and become a component of runoff.

This runoff can contaminate aquatic and terrestrial ecosystems.

Herbicide For a long time, humans

have puzzled over how to maintain the health of plants in their selected environment.

Using technology, we’ve created various poisons that reduce the number of pest plants that can harm these selected plants: herbicide.

Unfortunately, these herbicides will become a component of runoff.

Relationship City dwellers, as well as

rural citizens, often make use of herbicides.

A fraction of the herbicide undoubtedly enters local soils, sewers, and freshwater systems.

There are numerous species both macroscopic and microscopic that could be adversely affected by runoff contaminated with herbicide residues.

Purpose

The Purpose of this project was to see what effect different concentrations of Roundup have on a species of algae, Euglena gracilis populations.

Algae Are groups of organisms

containing chlorophyll that carry out photosynthesis

Most are microorganisms, but some, like seaweed, are macro-organisms

Produce more oxygen than any other plants in the world put together

Make excellent models because algae are the bottom of the food chain in most aquatic ecosystems.

Euglena gracilis Are single-celled organisms In the protist kingdom, because they

make their own food like a plant, and they eat food like an animal

They eat green algae, which makes them green

• Chloroplasts, too They grow on the surface of ponds or

marshes Have flagella that helps them move;

They sometimes attach to birds’ feet via mud, and get transported to a new body of water.

Undergo mitosis, a process of cell division, to reproduce.

Are hunted by baby fish, water fleas, mussels, frogs, and salamanders.

Herbicide Roundup® Weed & Grass

Killer Ready-To-Use Plus The active ingredient:

Glyphosate (2%), and Pelargonic (2%)

Other ingredients (96%) Glyphosate kills plants by

inhibiting the enzyme 5-enolpyruvoyl-shikimate-3-phosphate, or EPSP, synthase which forms the aromatic amino acids: phenylalanine, tyrosine and tryptophan

Effect of Roundup® on plant life

The main ingredient of Roundup, Glyphosate, can kill many species of wild plants in concentrations less than 10 micrograms, making it one of the most toxic commercial herbicides.

When aerial sprayed at 1200 to 2500 feet Roundup can kill wild flora up to 300ft from the field it was

sprayed on. Roundup has a half life of 47 days to 25 weeks in

soil and a half life of 12 days to 10 weeks in water.

Past studies Pesticide Information

Division of Plant Industry Directorate described the effect of only Glyphosate on Euglena gracilis’ cell density

The rate of photosynthesis was inhibited at concentrations of 1mg/L when exposed to Glyphosate for more than 20 minutes, but stimulated at concentrations of 50mg /L or greater.

Null Hypothesis

Roundup will have no effect on Euglena gracilis population density outside of chance

Materials A bottle of Roundup® 20 test tubes Euglena gracilis Micropipets and

Macropipets Spectrometer Spring water Light source (60 watt inc.

bulb) 0.22 Micron syringe filters Plastic wrap Beakers and storage bottles

Procedure Filled experimental test tubes with the following combinations of ingredients: 2mL

Euglena gracilis + 2.95mL of spring water + .05mL of 100% Roundup stock. This created a concentration of 1% Roundup.

Filled five test tubes with 2mL Euglena gracilis + 2.995mL spring water + .005mL of 100% Roundup stock. This created a concentration of .1% Roundup.

Filled five test tubes with 2mL Euglena gracilis + 2.9995mL spring water + .0005mL of 100% Roundup stock. This created a concentration of .01% Roundup.

Filled five test tubes with 2mL Euglena gracilis + 3mL spring water. This created a concentration of 0% Roundup, the control in this experiment.

Covered the top of each test tube with a piece of plastic wrap and mixed by inversion.

Placed all test tubes in an area of equal lighting (0.5 meter distance) and temperature (20C).

Measured the absorbance of the algae with a spectrometer at 430nm over 1 week. Readings were recorded on days 1, 3, 5, and 7

effect of roundup on Euglena gracilis populations

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

day 1 day 3 day 5 day 7

time elapsed

abso

rban

ce at

430n

m

0%

1%

0.10%

0.01%

% change of Euglena populations

-40%

-20%

0%

20%

40%

60%

80%

100%

0%

1%

0.10%

0.01%

P < .05

P> .05 P> .05

Conclusions

Based on rigorous statistical analysis I can reject my null hypothesis that Roundup will have no effect on Euglena gracilis populations for the 1% concentration of Roundup.

The same statistical analysis says I can accept my null hypothesis that Roundup will have no effect on Euglena gracilis populations for the .1% and .01% concentration of Roundup.

References “Euglena” <http://en.wikipedia.org/wiki/Euglena_gracilis>

(December 17, 2006) “Glyphosate”

<http://en.wikipedia.org/wiki/Glyphosate#Glyphosate_resistance> (December 15, 2006)

“Roundup” <http://en.wikipedia.org/wiki/Roundup> (December 7, 2006)

“Euglena gracilis” <http://bio.rutgers.edu/euglena/Euglenas/Egracili.htm>

“Glyphosate” <http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/glyphosate-ext.html>

“Effects of Glyphosate on Euglena gracilis” <http://www.pmra-arla.gc.ca/english/pdf/prdd/prdd_d9101-e.pdf> (November 22, 1991)