In microbiology, a genus of bacteria that retain the color of a gentian violet stain, aerobic bacteria, in the family Dermatophilaceae: The bacteria of the genus Geodermatophilus occurr in soil, with a tendency toward mycelial (mass of branched, tubular filaments of fungi) growth, the mass of fine branching tubes (known as hyphae) that forms the main growing structure of a fungus.

Visible structures like mushrooms are reproductive structures produced by the mycelium or the mass of fibers formed by certain bacteria.