Samples for XRD analysis are based on the biomass separated from an aliquot. A detailed description of this process was previously31 (link) given. Finally, the biomass was placed as thin and as homogeneous as possible on a homemade sample holder. The sample holder consists of a 1 mm thick and 25 mm diameter Si(977) single crystal mounted in a 32 mm diameter and 4 mm thick plate of polycarbonate, which fits directly to the support of the Phillips X-pert diffractometer employed for the X-ray diffraction measurements.