Had to Get Myself Back to the Garden 13

July 30, 2016

Now I’ll tell you my theory about why I didn’t find mature Leptothrix discophora film on the Schoepfle Garden side of the river and why I did find it on the other side. Two things you need to know. 1) L. discophora lives at the interface of water and air: one end of each rod-shaped bacterial cell sticks into the water, and the other into the air. 2) L. discophora thrives best in/on a mixture of water that contains a lot of oxygen and water that contains little oxygen. (Long story; I won’t go into it now, but ask if you want to know why.) River water, in running over rocks and other objects in its path, gathers oxygen. Ground water that seeps into the river has little oxygen because of the time it spends in the soil. (Although rainwater, which contributes to ground water, picks up oxygen as it falls through air on its way from clouds to earth, other microbes and roots in the soil consume much of it.) There has been so little rain lately that only larger seepages of ground water make it as far as the river. So guess which side of the river has more and larger seepages?