Kombucha bioreactor
After the class on synthetic development biology, I became intrigued by the idea of building a bioreactor. The only cells I've been culturing have been outside the lab, a kombucha SCOBY (bacteria+yeast) and sourdough. I wondered what electricity or vibration would do to the growth of one of these cultures?
Of course, I didn't expect to get a beating heart made of SCOBY, or even stretched cells (though I don't have a microscope good enough to check), but I think there are noticeable growth patterns (though to be truly scientific, I'd need to repeat the experiment a couple times with a lot more finesse, and blinded samples.)
I prepared 4 samples of the SCOBY, roughly 1cm x 2cm rectangles of (unfortunately) varying thickness. It was difficult to get an even thickness– looked like 3mm-7mm.
I let one grow on its own, put two on the fan, one with two electrodes going to a USB port (5V, 500mA), and one with two electrodes sitting on a non-vibrating surface.
The setup (the laptop is just used as a 5V/500mA DC power supply, biohazard vinyl for style)
0.7mm pencil electrodes
Each sample is testing different conditions. One just electrified:
One wobbling (on top of a window fan):
One both electrified and wobbling:
And, of course, a control (in the white dish)
after a week, I checked on the samples again.
Unfortunately, the elecrodes in the sample on a non-vibrating surface fell out halfway through the week, pretty much invalidating any observations. You can see that if they hadn't fallen out, all the water would've been electrolyzed away, as it is in the "both" sample.
Here's the control:
Here's a closeup of the control at 15x: (couldn't figure out how to get my optical microscope to zoom in any further)
Here's the electrified sample (the one which lost its electrodes)
The wobbly one's bacteria grew in an interesting pattern:
At 15x:
The one which was on the fan and had electrodes was the most interesting, all of the liquid electrolyzed away, the electrodes were absorbed into the SCOBY and split into interesting patterns (all the electrodes split into these gorgeous fragile crystalline things, I don't really know how. Graphite… sugar… um…)
The brown is where the electrode entered the SCOBY:
Here it is at 15x:
I don't feel I can safely conclude anything about the growth of SCOBY from this. The most interesting result is the clumps of brown bacteria gathering around the electrodes.
The wobbling kombucha did not beat the way a heart does, completely unsurprisingly. I'm interested to try again, perhaps with AC?