Run and Tumble

I started two Winogradsky columns this past weekend.

They’re really simple to set up and were invented by Sergei  Winogradsky, one of the founding fathers of soil microbiology. The basic concept is that you get some mud and water, put it all in a semi-sealed tube exposed to light, and watch as bugs set up shop.

The tube quickly forms zones containing different microenvironments; the bottom becomes anaerobic, the top stays aerobic, and other minerals form a gradient within the mud. The zones attract different bugs and often end up forming different colored layers.

There’s a rich interplay where one zone’s trash becomes another zone’s treasure; you end up with the major biogeochemical cycles in a can. The elegance of those cycles deeply appeals to me and is one the major reasons I’m gravitating towards environmental microbiology and bioremediation. I’ve wanted to make my own columns for some time.

As a bonus, the columns generate a mild but measurable electrochemical gradient. It’s not going to charge a laptop, but it is nifty.

I  loosely followed the procedure here. I took my samples from a nearby bayside park. Since the bay is saline and the local area was covered in acidic pine straw, I opted to use water from the site, rather than top off the columns at home. Why shock the bugs more than necessary? The mud had a nice black layer*, so I’m hoping for some ready-to-go sulfur reducers.

I used shredded newspaper for a cellulose source. For sulfur and calcium carbonate, I just boiled some eggs and crumbled the shells and yolks. I was all set to make a joke about albumin disposal via Carnivorous Albumin-digesting Trypsin Sacks, but it turns out neither of my cats like boiled egg whites.  Traitors.

I used some old speaker wire for the electric leads. Next time, I’ll use something stiffer.  Getting them to play nice with a multimeter’s probes was a pita. I did manage to make life easier by taping the wires in place before filling the column.  I’ll be taking measurements periodically and then posting the data in a few weeks.

The first column is a nice, cheap glass cylinder I got, at the awesome wife’s suggestion, from a craft store. It was in the ‘hollow glass things you can fill with beads and sand’ section. The second column is just a large plastic container that used to contain a ridiculous amount of biscotti. I’m planning on figuring out a way to puncture and re-seal the plastic so that I can get at the various layers. Bonus points if I end up using duct tape. Here are the columns, minutes after I finished inserting a lead into the mud-water interface and semi-sealing the tops.*

* photos forthcoming, as soon as my camera’s dongle turns up