July 2nd to 9th

I experiented different recipes to make idli come from India. I tried to do it with different rice and lentill (called dall in india). Finally, I chose to do this recipe with basmati rice and indian dall.


I did a media from an idli preparation. After fermentation of 18 hours, of ildi composed of 3 glasses of rice (75ml) and 1 glass of dall (25ml) before the soaking phase, I took water and butter mixed it together in 500ml bottle, and did an autoclave. I called this media "idli water", and it look like previously. I will just use the clear phase.

July 12th to 14th and 16th to 18th

I did grow ''Saccharomyce cerevisiae'' with mCherry and geneticin resistance genes in idli. I added 2 ml of a yeast growth solution (YPD) with an OD600 of 0.455 (around 1.2 x 10⁷ cfu) after the soaking phase and the mixing and grinding of rice (3 glasses of rice ~ 75ml) and dall (1 glass of dall ~ 25ml) together.The first try was to see if there are the fermentation process will this laboratory strain. After the fermentation time, I had plated the µorganisms come from the butter phase (middle phase between water on the top, and grind matter in the bottom of the erlenmeyer) on YPD with geneticin. I observed a lot of part of crush rice or dall, and just few colonny, not red like expected with the mCherry gene. The second try was more successful. This time I diluated the butter 10 and 100 time before plating, always on YPD and geneticin. I observed few colonies for the plate with the 100th and around 30 with the 10th.

July 29th

Test of the titration protocol with spectrophotometer for the Vitamin A (protocol titration)
I tested this protocol and tried to calibrate it. I used, like food sample, 1g of rice and I did 8 bottles with 8 different concentrations of pure vitamin A from 10 ^-1 to 10 ^-8 mg.ml^-1.

Results :
We can just observe concentrations higher than 10^-3mg.ml^-1.
^-1 = 1.625; 10^{-2-3-4-5-6-7-8}

dilution of the initial concentration	Value of the spectrophotometer
0.078
0.034
0.008
0.002
0.005
-0.001
0.000

August 14th

I had done idli protocol, with 75 ml of rice, for 25 ml of dall. After grinding and mixing, I added 2ml of ''Saccharomyce cerevisiae'' (with mCherry gene and geneticin resistance) that contained 10⁸ cells. I had plated at t0 and 2h, 4h, 6h, 19h30, 21h30 after t0 three different positons (middle top, lateral middle and bottom middle) at three different concentrations (10⁰, 10^-2 and 10^-3).

Like we can observe, the areas where I take sample for plating don't matter, and the yeast did't grow very well : just a doubling size of population during 22 hours of culture.