bread mold

[lil jo]

im thinking of doing an experiment on bread mold and i wanted to know if the different ingredients in different types of bread will effect the outcome. Basically, what should i controll for??
thanks,lil jo

[donnahardy2]

Hi Lil Jo,

You should check out the science fair project guide on the science buddies website. This guide will help you plan your experiment. You also need to learn as much as possible about bread mold. Here is a website that includes lots of background information: http://www.madsci.org/FAQs/micro/molds.html.

For your project, you will want to ask a question that can be answered with an experiment. In the experiment, you will keep all conditions the same, except one independent variable that you change. For example, if you want to find out how the ingredients in bread affect mold growth, you will want to have bread samples that are identical except one ingredient, like whole wheat or whole rye flour. The temperature, amount of light, and amount of moisture would be constant. If you use bread from the store, make sure your samples all contain the same preservative, or no preservative. Mold spores are always in the air, so if you put a piece of bread in the dark with the right amount of moisture and at the right temperature, it will always grow mold.

One problem that many bread mold science projects have is that results are not measured. It is always better to have an experiment with measurable results, so do plan this part of your experiment. You could measure the time it takes for the mold colonies to appear, measure the time until spores (the dark color of mold colonies), or measure the percent area of the bread that is covered by the mold. Perhaps you could think of something else.

Experiments with bread mold can make really great science fair projects, so I hope this will help you get started. Please do be careful and don't breathe the mold spores; always keep the moldy bread covered when you are working with it.

Good luck!


Donna Hardy

[610159]

I/k this has nothing to due with your question but I tried an expiriment like that once and nomatter what type of bread I used I wouldn't mold at all! So just to let you know, you might want to have a backup plan. =) :mgreen:

[donnahardy2]

Hi,

The key to growing mold for science fair projects is moisture. Mold spores are ubiquitous, bread is a good food source, and molds grow well at ambient temperature, so all you have to do is make sure the bread is moist enough(not sopping wet, however), and you will have mold growing within a few days.

Also, it's OK when a science fair project doesn't work as expected. You set up the experiment to test the hypothesis as carefully as possible, and then wait for results. If nothing happens, it's nice to have enough time to set up the experiment again, but if it doesn't work, you just report your results, explain what happened in the discussion/conclusion section, and state how you would do the experiment differently the next time. This makes a perfectly acceptable project that should satisfy all of the requirements for doing a project. Scientists do experiments all the time that don't work as expected.

Donna Hardy

[lil jo]

Thank you for responding, the website was very helpful. however it does not tell us which ingredients in bread that cause it to mold. also, we are thinking of doing flat breads beacause you can control for all the ingredients(flour,water, baking powder and salt). where can i get info about the different types of flourand if that is what causes it to mold.

thank you, lil jo

[donnahardy2]

Hi Lil Jo,

Bread is composed primarily of a carbohydrate (starch) and gluten (a protein) and so provides a complete food source for bread mold. Fungal spores are always floating around in the air, and when the spores land on a piece of bread that contains sufficient moisture, they will germinate and start growing. Fungi are great recyclers and there are fungi that will grow on any type of organic matter. Here is some additional information about the nutritional requirements of Rhizopus stolinofer, the primary mold found on bread:

http://www.thecanadianencyclopedia.com/ ... RTA0003108

http://www.backyardnature.net/f/bredmold.htm

http://www.madsci.org/FAQs/micro/molds.html

What happened in your experiment?


Donna Hardy

[lil jo]

hi, we went on to some of the websites that you mentioned. but i want to know which type of flour, wheat or white,
will mold more quickly . im having trouble finding info on that subject.

thanks, lil jo

[donnahardy2]

Hi Li'l Jo,

I've never seen a scientific reference on this particular subject. All types of bread will support the growth of mold, however, there might be a difference in the rate of growth, depending on the preservatives used in the bread. The moisture levels and temperature, along with a suitable food source (any bread) will allow mold to grow. You will need to determine the type of bread by doing a controlled experiment. What is your hypothesis?

Donna Hardy

[staryl13]

Hi!
Which bread molds the fastest is based upon the water content, so the drier breads will mold the slowest. Check out this link-
http://www.madsci.org/posts/archives/20 ... .Ot.r.html
Hope it helps good luck!

[lil jo]

hi there are all sorts of mold growing on the flat breads. there is a black/green mold , a bright bluish/green , a bright pink , purple , yellow/orange . we also have fuzzy white stuff which we found out is called hypae. it now has little black spots on it. our questions are : what are the different types of mold that i just listed called? we are having a hard tim finding info . we also need someone to explain the life cycle of mold because when we learned what hypae was called it talked about the life cycle but we could not understand it. oh 1 other thing, how are the hypae related if at all to the colorful spots of mold. thank you

lil jo

[donnahardy2]

Hi Lil jo,

Congratulations! It sounds like you have some great results and a good variety of molds. Here is some general information on mold identification, but keep reading this message so you will know why you should not actually try to identify the molds.

http://www.bre.umd.edu/agtopics/topics-marapr-22.html

Traditionally, molds are identified by growing them on little squares of agar that have a cover slip placed on top, inside a sterile Petri dish. The mold can be identified only after it has formed spores, and the cover slip is transferred to a glass slide and fixed so the spores can be examined under the microscope. The color and shape of the spores is the key to identifying molds, and there are hundreds of different species. There are newer techniques used for mold identification based on PCR, DNA analysis.

However, you should not try to identify the mold growing in your samples. You don't want to open the containers and expose yourself to the high concentration of mold spores that might be toxic, or that might trigger an allergic response. For your science project, just describe the color of the colonies. You can draw a picture of a mold for your backboard and correctly label the hyphae and spores of your cultures to show the science fair judges that you have done your background reading and learned something about your research topic.

Do you have any other questions about writing up your results? Be sure to look back at the original hand-out and make sure you have included all of the sections that your teacher wants to see in your project.

Donna Hardy

p.s. By the way, which type of bread resulted in the best growth?

[lil jo]

I'm writing for my daughter. They have finished the experiment. All the bread has alot of growth. How do they measure using graph paper. What we did is place the containers upside down on the xerox machine and got a picture. They then placed the picture on carbon paper with tracing paper and drew the parts that had no mold. This is very much an estimate as it's impossible to be precise. We were then going to use graph paper and count the squares. We're not sure how to do that. Do we need to count only whole squares or do we count a square even if only a small bit is on it. Also, they did get dates of first mold growth and then the first dates of the different colored mold growth. However, it appears they may have overlooked a mold on one of the bread types as it all has blue but they only wrote that to of the samples had growth. How should they handle that? Should they leave that mold out. How do they chart the dates of first growth of all the different molds? We have 3 different flat breads: WW, unbleached white and bleached white. We have 5 samples of each bread. We have first dates of mold, and then of the different colors: pink, purple, orange, blue, and the puffy cottony stuff. Can't figure out how to best chart this info. The ww started out more slowly, grew less variety but overtime they all grew alot of mold. It's hard to tell which has done best. Initially, it seemed that the bleached was growing the most. We hypothesized the opposite. Thanks for all your help and advise.
Sherri

[donnahardy2]

Hi,

Your daughter has done a nice job of collecting some semi quantitative data, recording the date of appearance of the white hyphae, and the date of appearance of the colored spores, as well as all of the colors. It probably seems like the data is too confusing to present, but you do want to present a brief summary of results so the science fair judges will be able to tell what has happened at a glance. Your idea to graph paper is excellent to estimate the percentage of the surface area. See if your daughter can look at the picture and decide what percentage of the total area was covered with mold, e.g. 50%

To present the results, I recommend doing a table, which will be in the center of your science fair board. Your table should be labeled "Summary of Results." Divide the table into 3 columns across the top, labeled "whole wheat (WW)," "unbleached white, (UW)" and "bleached white (BW)” and then divide the table into 4 or 5 rows labeled down the left side of the table "1. appearance of white hyphae (days) 2. appearance of colored spores (days) , 3. % covered at X days 4. % covered at Y days. 5. Total number of colors. Or something similar. Numbers 3 and 4 could include a drawing showing a typical result of each type of bread, along with a number e.g. 86%. Discuss the table with your daughter and use words that she is comfortable using. The results should be the average of the 5 slices of each type of bread. You can have your daughter compile a booklet containing the details results of all 5 pieces of bread for each type, but your results will be clearer if the results are distilled to a single number or picture in each box in the table. Make sure all numbers are labeled so the judges will understand what is being presented.

Now, the problem with the hypothesis. I suspect your daughter thought the whole wheat bread would support the growth of mold best because it has 26 more vitamins and minerals compared to white bread. Go ahead and compile the table, and see what really happened. Was there no difference, or did the while bleached bread turn out to be the best medium for mold growth? If the results are complete unexpected, your daughter will need to explain this in her discussion section, and perhaps describe another experiment that would resolve the question.


Donna Hardy

[lil jo]

Thanks for the feedback. Yes their hypothesis was that the whole wheat would grow more and faster. It turned out otherwise. The beached and unbleached came out fairly even with the unbleached having more colors. We think that the results refect the fact that the white breads had more moisture because al the breads were made with the same amount of water. Since whole wheat absorbs more water, the white breads had more available water to use in mold grwth. They also expected the bleached to do worse. On green mold and purple mold the unbl took 3 days and 5 .2days while the bl bread took 3.2 and 6 days. On the pink and orange the unbl took 4 and 5.6 days while the bl took 3.8 and 5.2. For number of colors unbl had 5 and bl 4.6. How can this be interpreted? Also on the orange mold, the ww only had growth on 2 samples. We did ther average based on just those two, but is it a good comparison to the others which had orange on 5 samples? The same thing with the blue. On the unbl my daughter only documented growth dates for 2 samples. She somehow missed the dates for the other samples so we did the average with just those 2. If the other dates had been done it would have made the number larger as they did have blue mold by the end of the experiment. This would then have been more favorable for the bl. Using the data we had , the bl and unbl both took 5 days.
Thanks.

[donnahardy2]

Hi,

Thanks for summarizing your results. Your data indicates that there is no significant difference between the UB and BW results. There's really no difference between 3.2 and 4 days, or 5.6 and 6 days. However there was a big difference between the WW and the other two samples. If you could tell that it was noticeably drier than the UB and BW breads after you added the water, then that would be the most likely cause of the difference. Did you check the bread labels to see if there is any difference in the preservatives used in the bread? Also, do you know if the bran in whole wheat has any natural anti-microbial properties? Can your daughter think of any other possibilities?

Whenever your hypothesis dos not turn out to be correct, it’s good to explain all of the possibilities for the actual outcome. It will make a better write up for the project. Your daughter could also describe a possible experiment that she might do to verify the original results and includes this in the conclusion section of the board.

Donna Hardy