preparation Spent coffee grounds (SCG) were obtained from a coffee automat machine atthe Faculty of Chemistry, Brno University of Technology, Czech Republic. The wastematerial was firstly dried to the constant weight (80◦C for 24 h). The coffee oilextraction was performed with n-hexane as described by Al-Hamamre et al. [17]. Tohydrolyze the hemicelluloses of raw material, 15% (w/v) SCG were firstly treated by1 vol.% H2SO4for 90 min at 121◦C [16]. In the next step, the enzymatic digestion wasused to break up cellulose releasing fermentable saccharides. The refore, pH of thesuspension af ter the acidic hydrolysis was set to 4.5 (10 M NaOH) and cellulose wastreated by 0.5% (vol/vol) of Celluclast 1.5 L (Novozymes A/S, Bagsværd, Denmark) at50◦C under permanent shaking (150 rpm) for 24 h [16]. At the end of the processthe solids obtained after enzyme treatments (representing approx. 30% of SCG afteroil extraction) were removed by filtration and the permeate, called spent coffee grounds hydrolyzate (SCGH), was used for the cultivation media preparation and the PHA production.