Is the Bacteria Living in Our Environment Harmful To us?

Disease Ecology:Bacteria

A presentation created by: Tamanisha John & May Choi

What is Disease Ecology?

Disease Ecology is the study on how diseases spread through and impact host populations, and how hosts, pathogens, and their environment react and evolve in response to one another.Ticks are skin parasites. They

like motion, warm temperatures, and carbon

dioxide exhaled by mammals.

I. What are Bacteria?

Bacteria are living single-celled organisms who are neither plants nor animals. Instead, they belong to their own group.

single-celled microorganisms appeared on earth about 4 billion years ago. Scientists say they were the first life forms on Earth.

Living Organisms Below:

PlantsAnimals

Bacteria

II. What Are Bacteria?

Bacteria come in three main shapes:

Spherical (like a ball)

Rod Shaped

Spiral

Did you know thatPlanet Earth is estimated to

hold at least 5 nonillion bacteria!(Nonillion in U.S. means there are

30 zero’s after a number, while in the U.K there are 54 zero’s

after the number. We’re using the U.S. version)

(medicalnewstoday.com)

Spherical are usually referred to as cocci

Rod Shaped are usually referred to bacilli

Spiral are usually referred to as spirillia

Bacteria: The Good, The Bad, & The Ugly

The Good:

Without bacteria we would die. The good bacteria help us digest our food and they live on our skin and in our

mouth to provide protection against bad bacteria.

The Bad & The Ugly:

Simply put, can either make us sick

or dead.

Why do you think we used

tooth pictures?

Agar V.S. Gelatin

Jell-O

Why Can Gelatin Substitute Agar?

Gelatin can substitute agar because they are both gelling agents. Agar, however, is more

preferable due to its long term solidity, meaning that unlike gelatin, which is liquefied

easier, agar will stay solid.

Think of Gelatin as ice, it won’t stay solid forever.

The Aim Of Our Experiment:

Is to figure out whether or not the bacteria in our school have a negative or positive impact on our environment. To decide whether or not they are harmful, we plan to harvest the bacteria we collect and place it on an apple slice in order to

see whether the apple slices rot or turn bad quickly. If the bacteria have a negative affect on the apple slices, it will probably be a bad thing

for our environment.

Our Hypothesis

Since bacteria can only be considered very dangerous in large amounts, but even then, small amounts of bacteria can reproduce rapidly, we do

not think that the bacteria in our school is any more harmful than the common cold because we

all act and interact with our environment daily and nothing too serious (like someone dying) happens.

Do you think the bacteria in our school

is dangerous?

Materials:Gelatin (Jell-O), Microscope, Beaker with Water, 3 Q-tips, 3 Petri Dishes, 3 Zip Lock Baggies, Marker, Knife, Gloves, Tape, Bleach, Apple

Before Starting Our Experiment:

we collected bacteria from a toilet handle in the girls bathroom, one of the computer keyboards in

Meghan’s office, and one of the auditorium chairs in the auditorium. Then we swiped the collected

bacteria in our Gelatin, secured our collected data and went on winter break

The Experiment

Safety Steps to Consider:

1.Wear Gloves when handling bacteria

2. Wash Hands Frequently

3. Bleach bacteria at the end of experiment

What Do They All Have In Common?

Mold!

Mold is a type of fungus (an organism that lacks chlorophyll and feeds on organic matter) and some funguses are

pathogenic. Mold travels through the air in the form of tiny spores (not visible to the naked eye) and like to make their way to damp and moist areas so that they can breed and

multiply.

Data and Results:

All of the apple slices weight gradually decreased as they started to rot. However, our control’s apple slice weighed

more than any of the other apple slices indicating it wasn’t rotting as quickly. We noticed that our control’s apple slice will decreased by about 2grams while all the other slices

decreased by about 3grams.

0

5

10

15

20

25

1/5/2011 1/6/2011 1/7/2011

Control

Girls Bathroom

Meghan's Office

Auditorium

I. Observations

On the second day of our experiment (1/6/2011), we observed that our control apple slice and the one with bacteria from a keyboard in Meghan’s office were soft

around their edges, but hard on their backs and middle slice while the other two were softer.

II. Observations

On the second day we also noticed that our mold turned grey, which, according to gardenline.usask.ca , means that our mold must’ve gotten cooler and wetter than before, which did happen since each day our Gelatin

got more liquefied.

& Our Hypothesis Was…

Partially Correct! During the course of our experiment, we found the bacteria from the toilet handle

in the girl’s bathroom can be considered dangerous.

Looks like my job won’t be

over anytime soon

Thinking Outside The Box

To figure out why the girls bathroom bacteria rotted its apple faster than any other

bacteria, besides the fact that it must’ve multiplied faster, we

ran a survey in our school surveying 25 girls (both

teachers and students), in order to figure out how they flush the

toilet. Out of the 25 girls surveyed, 20 flushed the toilet

with their feet, while 5 girls flushed the toilet with their

hands.

Sources Of Error

•Other occurring experiments that could’ve added carbon to the air (i.e. the experiments with fire)

•Natural air borne bacteria which could have had an effect on the rotting processes of our apples, since they could have

been attracted to the bacteria we collected and put on them and speeded up the rotting process

•Survey’s small sample size

Future Experiment:

Only collect bacteria from the girl’s bathroom toilet handle, but a week in advance, “monitor” or put up a sign in the girl’s bathroom

saying ‘Do Not Flush Toilet With Your Shoes, Experimental Reasons,’ in order to collect more accurate data without the

possibility of shoe germs.

While conducting our survey, the usual response was: “Ew, who touches that dirty handle?” If every girl assumes the handle is dirty, then there’s less of a chance that any of them would want to touch the handle, therefore, they will use their shoe and shoe

germs will get on the handle.

Why Would You Do That?

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