Thursday, April 14, 2011

Oh, and one more thing

Just about an hour ago I received an email from a fellowship committee that I did not receive a dissertation completion fellowship. While it is possible that my application was sub-par, or that my letter of reference was weak, I can't help but wonder if the committee read my application and thought, "Diatoms? In my entire life I've never heard of such creatures. Why should I care about them now, especially in such dire financial times, when I could fund an applicant who studies something important, like cancer?".

Well, I'm here to set the record straight. Diatom research may not cure cancer (as far as we know), but there are so many applications of diatoms to people's everyday lives.
I'll start with an anecdote. Before I knew anything about diatoms, I took an animal science course at UMass. During one class we visit a farm, where we learned that a popular method for dealing with intestinal parasites was to add diatomaceous earth to the animal's feed. Diatomaceous earth (DE for short) consists of the glass remains of dead diatoms. In some parts of the earth there are huge deposits of DE from highly productive oceans. The DE is inorganic and accumulates in sediments.
The tiny glass bits of broken diatoms act like tiny microbial razors to cut up the offending parasites. From that class on, I knew diatoms were special. Apparently, diatomaceous earth also controls worms in dogs and cats (who knew?!!).

Image: Diatomite mine in Nevada. That white, chalky stuff is all diatoms! (ref 1)

Here's just one more reason people should know and care about diatoms. As I mentioned in the previous post, they are abile to biologically transform silica to from an intricate and repeatable silicate structure, called a frustule. Frustules are amazingly beautiful and have been the object of many artists' attention.

Images: diatom art (ref 2)

Now for the applied part. Humans would really like to capture the inherent ability of diatoms to create this repeatable nanostructure to create highly useful products like semiconductors (ref 3). Current industrial processes are hugely energy intensive, and yet diatoms do it all of the time using proteins. There is also much interest in using diatom frustules for drug delivery (ref 4) and even as an energy harvesting element in solar cells (reviewed in ref 5). The tiny diatom pores in the biological solar cells greatly increases efficiency compared to traditional solar cells.

Image: layout of a diatom-titanium dioxide thin film solar cell (ref 6)

Those are just two HUGE ways that diatoms affect the lives of everyday people. I may not have made that clear enough in my 750-word application, but I hope that I have convinced anyone who reads this that diatoms are worth of our attention.

1. Diatomite image:
2. Diatom art:;
3. Gordon et al. The glass menagerie: diatoms for novel applications in nanotechnology. Trends in Biotechnology 27(2): 116-127.
4. De Stefano et al. Inerfacing the nanostructured biosilica microshells of the marine diatom Coscinodiscus wailesii with biological matter. Acta Biomaterialia 4(1): 126-130.
5. Chapter 35 in: The diatoms: applications for the environmental and earth sciences (vol II). 2010. J. Smol, editor. Cambridge University Press. 686 pages.
6. Greg Rorrer lab, Oregon State University.


  1. Also in toothpaste, don't forget that!

  2. I LOVE your blog! What a worthwhile career you have... congratulations! Maybe we will see you give a presentation of your work at T.E.D. someday soon.

    If you have not read BIOMIMICRY by Janine Benyus it is well worth your time. New tricks and Ideas and Solutions to environmental problems that have already been solved by natural organisms. Your reference to diatoms and improved solar cells is a prime example of the work of MY HERO Janine Benyus.

    Cheers! All the Best to you.

  3. Diatoms can solve water pollution and perhaps climate change / global warming problems too.

  4. very cool blog! i am a biology phd student at indiana university and love to hear about what other young scientists are up to. i also have a blog, Its about the ecology, silly," if you'd like to check it out. my dissertation has been taking the front seat lately and i haven't been posting as frequently as i would like, but it still may be of interest to you. one of my interests is how microbial co-infection influences disease dynamics, so i too *heart* microbes :) good luck!