Team:ITB Indonesia/Project/Future

To make Aflatoxin whole cell biosensor much better we had made a planning to improve our system or add another modul in Aflatoxin biocensor system.

OVERVIEW OUR FUTURE SYSTEM

1. Reporter system in Modul 1 (Activation AFB1 become Exo-AFB1-8,9-epoxide)

We want our device is ready to detection Aflatoxin B1, so we use a constitutive promotor to expression CYP3A4 gene. To make sure this modul work  easier or without using SDS PAGE we plan to adding VioABE as reporter gene  to modul I, so we can observed that expression of CYP3A4 gene successfully with easier than before. VioABE is Chromogen that can convert L-tryptophan to prodeoxyviolacein that have green color so when our device is ready to detection aflatoxin, the device will show the green color.

2. Reactive sequens (Another modul)

In research by  Bennasuti (1988) the active form of AFB1, Exo-AFB1-8,9-epoxide, will adduct DNA at guanine base in N(7) position. Because the intensity of guanine in DNA different in any region, he try to investigate in where aflatoxin will more reactive to guanine in DNA. He discovered that pentanucleotide sequens, 5’-WXGYZ-3’, will make aflatoxin more reactive to adduct guanine in DNA. The underline G means guanine base, and W,X,Y,Z can be another sequens. He showed that nucleotide in W and Y position will influence the reactivity gunanin base to adducted by Aflatoxin. The chances of every nucleotide influence gunaine more reactivi in X position is G(1.0) > C (0.8) > A (0.3) > T (0.2), and in Y position is G (1.0) > T (0.8) > C (0.4) > A (0.3). According to the research, we try to make a sequens that will enhanced the reactivity of aflatoxin to adduct guanine in DNA, so the measurement of concentration of aflatoxin will more accurate

3. Modulating system in modul II for amplify the signal.

We want our device can detect aflatoxin more rapid and more accurate so we need a system to enhance the signal from DNA damage to promotor SOS. We plan to add POPS system for modulating signal DNA damage by aflatoxin and send them to promote SOS.

4. Buoyancy system (another modul)

The alfatoxin biosensor will produced in syringe pack. So it will hard to observed the changing color as indication of the presence alfatoxin in suspension form. So we try to concentrate the cell in one line using gas vesicle that produce by cell when aflatoxin detected.

[1] Benasutti, Matt., Ejadi, Samuel., Whitlow, Marc D., Loechler, Edward L. Mapping the Binding Site of Aflatoxin B1 in DNA: Systematic Analysis of the Reactivity of Aflatoxin B1 with Guanines in Different DNA Sequences.