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Team:Sharon MA Aquila
From 2012hs.igem.org
Team
We are a group of students from Sharon High School in Sharon, Massachusetts. Our two mentors, Mr. Snow and Mr. Dixon, are biology teachers at our school.
These are our team members:
- Hannah Binney
- Frank Zhou
- George Rakushkin
- Rachel Fyler
- Brahm Gardner
- Gabby Crosby
- Nancy Chinnapan
- Peter Jiang
Project
The purpose of our project is to insert antifreeze protein (AFP) into yogurt cultures. Milk is converted to yogurt using Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus bacteria. These cultures ferment the lactose sugar present in the milk and convert it to lactic acid, which gives yogurt its distinctive taste and texture.
AFP is a protein produced by plants, fungi, bacteria, and some vertebrates to prevent the formation of dangerous ice crystals at subzero temperatures. AFP is about 300 times more effective than industrially produced antifreezes at the same concentration, so they have many possible commercial applications, including cryosurgery, hypothermia treatment, and farm fish production. Some companies have also started isolating AFPs from fish and introducing them into milk and yogurt products. The protein could help prevent freezer burn and improve the texture of the yogurt (frozen or otherwise).
Our project will instead introduce the AFP-producing gene directly into the Lactobacillus bulgaricus bacteria, so that it is constantly produced as the bacteria metabolizes lactose. Hooking up production of the protein to the lactose sensor already present in the bacteria would allow continuous production of the protein. Since transplantation of a small quantity of yogurt cultures can be used to produce another batch of yogurt, our altered bacteria would easily be able to replicate and produce AFP in new batches.
Notebook
March 13: After looking through old iGEM projects for inspiration, we stumbled upon a project dealing with antifreeze protein (AFP) production. We began brainstorming possible applications of this protein, which prevents ice crystal formation in certain fish, plants, fungi, and bacteria. We discussed using AFP on roads, but after researching activation methods for road-thawing bacteria, we determined that we would have to introduce another material (arabinose, lactose, etc.) in order for our bacteria to begin producing the protein. Briefly, we researched cold activation methods, before determining that these methods were generally difficult to implement and only operational at temperatures above zero - not to mention that bacteria are usually nonfunctional below freezing.
March 20: After some discussion with Mr. Dixon and among the group members, we decided to take an idea from the 2008 MIT iGEM team, who created teeth-cleaning bacteria by transforming the bacteria used for yogurt cultures. We decided it might be a good idea to introduce the AFP gene into one of the yogurt bacteria, which would already be present in the food we were trying to affect. We additionally decided that the gene should be activated by lactose, because it was already present in the yogurt and because the bacteria already reacted to it to produce lactic acid.
After researching the two bacteria present in yogurt cultures, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus, we determined that the former is more suitable for our experiment, because it generally remains in the yogurt following yogurt production - and because the MIT team wiki had detailed protocols regarding transformation of Lactobacillus bulgaricus bacteria.
Results/Conclusions
What did you achieve over the course of your semester?
Safety
What safety precautions did your team take? Did you take a safety training course? Were you supervised at all times in the lab?
Attributions
Wiki: Hannah Binney, Frank Zhou
Fundraising: Rachel Fyler
Human Practices
What impact does/will your project have on the public?
Fun!
What was your favorite team snack?? Have a picture of your team mascot?
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