Team:Tokyo Metropolitan/Project/Rice

From 2010.igem.org



Rice Master of E.coli Project

Tmu ecoli rice master.png

Contents

Introduction

 Japanese unique project
Rice is Japanese staple food, and one of the farm products that the rate of food self-sufficiency is high. It is said that rice is symbol of Japan, and it is not too much to say that this is the center of the gastronomic culture in my country. A unique project in Japan was completed by making E. coli that is evaluate the quality of such rice. Delectable Japanese rice may well appeal to the world through this project.

 Ratio of amylose
The principal ingredient of rice is starch. Starch consists of the two components which are amylose and amylopectin . Rice (nonglutinous rice) in Japan is richer ratio of amylopectins than the Indica rice in foreign country, and This Japanese rice consists in 80% amylopectin and about 20% amylose. The ideal balance of this amylopectin and amylose decide its quality of rice. One of the most delectable rice in Japan is Koshihikari, which consists of the 17~19% amylose and 81~83% amylopectin so the content balance is ideal.

Mechanism

 The role of the amylase
The primary component of rice is starch, the starch consists of amylose and amyropectin(reference to right side). Amylase resolves these two ingredients into the simple structure of glucose. E.coli can propagate by using glucose, but cannot use polymer of glucose. There are some kinds of amylase, and we choose α-amylase as suitable for this project. Although the α-amylase cut off α1-4 combination from end and resolve all of the amylose into glucose, it cannot cut off α1-6 combination and cannot dissolve amylopectin. The difference of glucose is decided by the propotion between amylose and amylopectin. As a result, the amount of E.coli is fluctuating. Here, so called E. coli “A” is rice master, and it can make glucose as their baits, which enables to get them to E.coli “B”. In fact, B emit a certain colorful matearial. Therefore, A secreate α-amylase as its primary work.


Model

 Two Constructions Model of Rice Master
We suggest that a new model, which is Two Constructions Model of Rice Master. We have already mentioned above that there are E.coli A and B in rice master. But here, I would like to say that their roles are different, which first of all, I touch on A below. And, we make A generates α-amylase and emit them into the medium by explosion. Our teams will try to dissolve cell and make it emit α-amylase to produce glucose.
On the other hand, B emits RFP according to interaction on by increasing. What we choose is quorum sensing model. Therefore, if the glucose is less than being expected, B could not get interaction and has no emission. On the contrary, if glucose can be find a lot, B will increase and emit a lot by strong interaction each other. In the end, we can discern the total amount of glucose by this strength of color emission after some periods.
By the constructions of above measures, it would be possible to decide the quality of rice by doing two kinds of ways in production and quantitative analysis.