The SciFund Experiment: Yeast Adaptation to D2O

It has taken me quite a while, but I’m finally at the point where I can begin the experiments that my SciFund quest funded. To refresh your memory, here is my project proposal:

Water is arguably the most important molecule in the universe. It’s a simple molecule that is composed of two hydrogen atoms and one oxygen. But did you know there are different types of water molecules? Every element has alternate forms known as isotopes, and hydrogen is no different. A common isotope of hydrogen, known as deuterium (D) which is twice the mass of hydrogren, can bond with oxygen to make heavy water (D2O).

Immediately after heavy water was first purified from naturally occurring water in the early 1930s, it was discovered that most organisms cannot survive in pure heavy water. It was also shown that increased (but not toxic) levels of heavy water significantly affect many systems in these same organisms, like fertility, metabolism, temperature regulation, and many more, all of which are essential for healthy organism function. Interestingly, on a cellular level the increased mass of heavy water may affect chemical processes. Not many studies have been performed in this area, unfortunately, because many experimenters ignore the effects of water even though it is by far the most abundant molecule in these experiments.

Because of the presence of deuterium in naturally occurring water, life may have evolved essential uses for deuterium. I plan to study the effects of heavy water on E. coli and S. cerevisiae (baker’s yeast). I will be growing cultures of these microbes in water with varying amounts of heavy water (from 0% to 99.9%) and comparing characteristics between the cultures, looking for effects in growth, development, appearance, and other physical differences.

But that isn’t specific enough to describe what I actually intend to do with the money. The full explanation of the experiment is way cooler!

Initially I’m going to continue the experiments from April and May that compared the growth of yeast grown in DI water, DDW, and D2O. Each time I did a time trial experiment I would start from scratch to show that yeast grows much slower in D2O. This time I’m going to carry over the yeast each day. Over time I hope to show that the yeast is adapting to growing in D2O and begins to develop at a similar rate to how it develops in DI water and DDW.

Once that happens I’ll be doing two experiments.

First I’ll be looking for phenotype differences between yeast grown in H2O vs yeast grown in D2O. I’ll be looking for shape, size, motility, etc of the yeast using the lab’s light microscopes.

In the second experiment, I’ll flip the script on the yeast. Once I get the yeast to adapt to D2O, I would like to determine if H2O is as harmful to D2O adapted yeast as D2O is to H2O yeast (aka natural yeast). I’ll do this by growing the D2O adapted yeast in DDW/DI water and recording the growth. No matter what happens with this experiment, the results will be interesting.

  • bill

    Do you know anyone who is doing 2-D protein gels? If you can find someone to do it, a 2-D gel might give you a rapid overview of major protein changes (if any) in the D-adapted yeast. Alternatively, can you think of any likely protein targets for D-adaption (e.g. aquaporins)? You could look at those with a regular old western blot. Just thinkin’ out loud here.

    • Anthony Salvagno

      I’ve never heard of 2D gels or aquaporins before! Both sound like interesting avenues to explore. I know a yeast specialist here at unm that I could speak with that would be able to provide insight into possibly affected mechanisms and maybe would know if anyone here does 2D gel analysis. Thanks for pointing these avenues out! I love open science…

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