The Gradients Explained

Much has been made on this blog of the oxygen and hydrogen sulfide and aerobic/anaerobic gradients  of a Winogradsky Column. Some explanation may be necessary.

Source: Schematic view of a typical Winogradsky Column. Image credit: Jim Deacon, University of Edinburgh

This image above lays out the layers that develop in a Winogradsky Column. Our control column should develop along these lines. Our controls shoud disrupt this development nicely.

 Source: http://www.personal.psu.edu/faculty/j/e/jel5/biofilms/winogradsky.html (the author of the image is unfortunately not credited).

This image lays out the aerobic/anaerobic zones, a 40-60 split, respectively as well as the oxygen and hydrogen sulfide gradient. We expect a nice disruption of this gradient too. A note should also be made about the Green and and Purple Sulfur bacteria layers. They engage in a form of photosynthesis where hydrogen sulfide serves in the place of water in a typical photosynthetic reaction. More on this in  a later post.