Fourier-transform spectromicroscopy imaging of three samples of archaea-dominated biofilms from the Muehlbacher Schwefelquelle, using the Berkeley Synchrotron Infrared Structural Biology facility’s bright infrared beams, differentiates between archaea and bacteria by their lipid and carbohydrate signatures and shows that organic sulfates and carbonated minerals are located with the bacteria. Credit: Lawrence Berkeley National Laboratory, BSISB