The filaments in this image are without the capping bacteria.
Transmitted Oblique Illumination
Gillionella is one of the filter plugging, iron-loving bacteria. It is very distinctive in that it forms as two entwined, iron
hydroxide filaments. The bacteria itself are the paired circular objects at the top of the helix. These are easily
displaced during sample preparation or may be missing in the sample due to the fact that it is the collection of filaments
that plug the filter and the bacteria may be growing at another location in the system.
Significance in the Environment:
The most obvious features Gillionella are its orange color in bulk and its helical stock under the microscope. The rate of twisting can be
measured by how frequently a flat view of the ribbon is given. The ribbon gives a flat view every 180 degrees. The frequency of these flat
views ranges from one every micrometer of length too one about every three micrometers of length. That corresponds to a full twist every two
to six micrometers.