FIG 1.

Transmission electron micrograph of a resuspended cell pellet of the methanogenic limonene enrichment culture. We assigned the large filament to Methanosaeta, based on the spacer disc at the lower end of the filament and the presence and structure of a sheath (see Fig. S1). The cells may have been shrunk by the TEM preparation. The small black cells with a gray cape were assigned to the ultramicrobacterium OP3 LiM (triangles indicate OP3 LiM cells). Bar, 1 μm.