Abstract
We found a reddish brown pigmentation at a small stream of a biotope in Aina, Atsugi. As a result of optical and scanning electron microscopic observations, and elemental analyses, we confirmed that the coloration of reddish brown is originating from the iron oxide attached to the surface of cylindrical shaped microorganisms. Based on the morphological features, this microorganism was supposed to be a kind of iron bacteria and tentatively determined as Leptothrix sp., though further investigation is needed for identification.
