Red Mats

Thick red microbial mats are found near the side stream channel between the Upper and Lower Springs. A pen is in the lower left corner for scale. These mats form at the base of a large gypsum pile, in which water flows through the mats. These mats are >50% dry weight Fe based on elemental analysis.

The SEM images below show interesting biological structures characteristic of iron-oxidizing bacteria. There are also associated crystal shapes.  Thus far, we have identified iron-oxidizing bacteria, sulfur-oxidizing bacteria, and aerobic heterotrophs. There is a low percentage of anaerobic organisms from this type of mat.

Scanning Electron Microscopy of Microbial Mat and Sediments:

Microbial biofilms and sediments were preserved in gluteraldehyde, then freeze-dried. Prepared samples were gold-coated and observed using the JEOL SEM in the department. The images were digitally captures and the size was adjusted to fit on the web-page, causing some distortion. 

 
Sheaths of iron-oxidizing bacteria associated with a mixture of possible cells or minerals.  Twisted stalk characteristic of Galionella, an iron-oxidizing bacteria.  
Sheaths of iron-oxidizing bacteria associated with a mixture of possible cells or minerals.  Twisted stalk characteristic of Galionella, an iron-oxidizing bacteria.  

  Last updated:  07/13/09   Images, maps, and other original material copyrighted by Annette Summers Engel, Baton Rouge, LA, USA.