Colony biofilms as shown in Figure

Colony biofilms as shown in Figure 1B were prepared on
13-mm polycarbonate filters (0.2-μm pore size, Sigma,
St. Louis, MO, Z365041) as previously described [7,23]. Diluted
H. volcanii culture (OD 600 nm = 0.1) was transferred
onto the surface of sterile filters previously placed directly
on the surface of the solid medium with sterile forceps.
After the culture medium penetrated the filter and evaporated,
the plates were inverted and incubated. Filters were
transferred to fresh plates under sterile conditions every
48 h during the growth period.