4.8. Solid content measurements

The solid content of the biofilm colonies was obtained by growing the biofilm on LBGM plates. LBGM plates were inoculated from an overnight culture (100 ml) using an L-shaped spreader to evenly distribute the inoculum around the agar surface. After 24 h incubation at 30°C, the biofilms were gently scraped off the agar plates and transferred to glass slides. The samples were weighed on a high precision scale (XS105, Mettler Toledo) to determine the weight of the hydrated biomass and placed in an oven at 110°C under vacuum (10 mbar during 20 h). The dry weight was then measured on the scale. The solid content was calculated with the following equation:

with w_dry being the dry weight of the sample, w_g being the weight of the glass slide and w_hydrated being the hydrated weight of the sample.