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BACTERUINO

@Ju_Pichon

@FdvJulie

@FranckPrts

Archaea &

ohmmeter

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To sum up this week...

3 motivated students

Halobacterium which are actually not bacteria…

An Arduino sensor without a sensor

40 000 data to analyze (thanks TecanInfinity)

Archaea which make a colony in 7 days

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Why did we choose these sensors?

Halobacterium

DIY Ohmmeter

Extremophilic archaea → Can live in high salted-media

Growth rate depends of the concentration of salt in the media

So we can link growth rate with conductivity

Have a range of 0.1M to 5.1M

Easy and fast to build

Need little material

Analog to digital data

Can give to us the conductivity

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Protocol for Halobacterium

24 hours

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Protocol for electronic sensor

0 2.6 3.5 3.9 4.3 5.1

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In the real life

Voltage Divider Calculator :

Rb = Ra * (Vin - Vout)/Vout

Ra = 470Ω

Vin = 5V

Vout = Arduino measurement

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Results of electronic sensor

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Results of arduino compared to ohmmeter

Saturation at 2.6 M/L for arduino

Some bias with ohmmeter:

Not have the same distance between the 2 electrodes
Not immersed the 2 electrodes in the same volume

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R² for each concentration

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Bibliography

Leuko, Stefan, Mark J. Raftery, Brendan P. Burns, Malcolm R. Walter, et Brett A. Neilan. « Global Protein-Level Responses of Halobacterium Salinarum NRC-1 to Prolonged Changes in External Sodium Chloride Concentrations ». Journal of Proteome Research 8, n^o 5 (mai 2009): 2218‑25. doi:10.1021/pr800663c.

« Halohandbook_2008_v7 - Halohandbook_2008_v7.pdf ». Consulté le 25 janvier 2017. http://www.haloarchaea.com/resources/halohandbook/Halohandbook_2008_v7.pdf.

Kish, Adrienne, Patrick L. Griffin, Karyn L. Rogers, Marilyn L. Fogel, Russell J. Hemley, et Andrew Steele. « High-Pressure Tolerance in Halobacterium Salinarum NRC-1 and Other Non-Piezophilic Prokaryotes ». Extremophiles: Life Under Extreme Conditions 16, n^o 2 (mars 2012): 355‑61. doi:10.1007/s00792-011-0418-8.