Based on the results from yesterday I’ll be carrying out the next phase of the experiment. I set up starter cultures to grow in DDW, DI water, and D2O so I can do hourly time points tomorrow starting early and hopefully getting about 7 hours of data (instead of 5 like yesterday).
I had grown yeast on solid media yesterday and got a bunch of colonies today, so I plucked three colonies and inoculated them in the liquid media stated above (YPD broth).
Here is the data courtesy of figshare:
S. cerevisiae growth in DI Water, DDW, 50% D2O, and 90% D2O. Anthony Salvagno. Figshare.
Retrieved 22:01, May 22, 2012 (GMT)
hdl.handle.net/10779/bfceb213ffb663b34149d97141755232
I would say this data is pretty exciting. Unlike the E. coli data (which was all over the place), there is a clear difference in growth rates between the D2O samples and the H2O samples. Also the growth between the DDW and DI (the H2O samples) were almost identical! That’s pretty solid.
Yesterday I created a starter colony of yeast from the lyophilized yeast that I ordered from ATCC.org. Today I’m doing growth in different water types and checking the growth every hour just like the e. coli experiments. Here is my setup:
Simple!
So before I left on travel (a week and a half ago) I received a vial of dry yeast. I’ve kept it in the fridge for 2 weeks to preserve it and today I’m going to bring it to life and start a starter culture so that this week I can do time point growth, like I did with the E. coli. Here is some information about the yeast:
And here is some information on how to go from the powder to a liquid suspension and then to a culture (provided by ATCC):
And the recommended incubation temp is 30C.
I have no idea when this will get here, but I put in an order for some new S. cerevisiae. I think on Monday I’ll have Alex grow another starter culture and then on Tuesday, we’ll try and get better resolution under the microscope than we got last time.
Anyways, here is what I’ve ordered (from ATCC.org).
These are the results of the “experiments” we did yesterday and Tuesday. The difference between the samples is that the cultures from Tuesday were streaked from a colony on another plate whereas the cultures that grew last night were streaked from liquid media. So it seems this yeast doesn’t grow so well from a single colony on agar. Further evidence to prove that I should just get a more common strain.
First off, how come yeast has a common name but E. coli doesn’t? Can we call it shitus?
Anyways yesterday Alex and I did some follow up work after starting some cultures. She did a good job notebooking the experience so I won’t double up on her thoughts. Check that out here.
We took some pictures of the e.coli and the yeast which turned out pretty bad. I’ll have to try and take some better images today or something. In general though it looks like the yeast we have isn’t what we thought it was. It may not be a mutant of S. cerevisiae but may be some version of Schizosaccaramyces pombe (I hope I spelled that right, I like the first name a lot) because it looked nothing like budding yeast.
The result of this is that I will be ordering some new yeast straight up from atcc.org that is of some variety that I commented on in Alex’s notebook (hopefully).
I just wanted to get this up today. Here is my #SciFund proposal on Google Docs. It is publicly open for comments. I won’t have a rough draft done until later today or early tomorrow so be sure to check back frequently. But in the spirit of open notebook science, I figured everyone deserves a chance to see the evolution in real time.
I’m showing Alex some sterile technique and how to inoculate yeast and e. coli via liquid media and solid (agar) media.
Today we plucked a few colonies of yeast from our starter batch (which may need to be replenished soon) and streaked the cells onto some YPD plates. One plate is in an incubator/shaker at 24C and the other is sitting at RT. We also inoculated a colony in 10mL of YPD.
For the E. coli, we did essentially the same thing, but we are doing 1 plate of LB media (agar) and 1 10mL test tube of LB broth.
Tomorrow we will try for some OD readings, and then we will try to setup time point growth experiments. It should be noted this is all in regular H2O. Right now I want Alex to get familiar with the process and then we will start doing some DDW and D2O studies probably in a couple of weeks.