Polyhydroxyalkanoates (PHAs) are biobased and biodegradable polymers, and represent an interesting alternative to petroleum based conventional plastics in the future. While their thermoplasticity and the big variety of usable monomers lead to extremely versatile materials, their biggest drawback are still the high production costs. As the raw materials were determined as some of the biggest cost factors, cheap waste products are investigated for the usage as fermentation substrate. In this master's thesis, a fermentation process for P(3HB), based on a chicory root hydrolysate, was investigated and optimized. The fructan inulin was extracted from chopped and dried chicory roots and enzymatically hydrolysed to fructose and glucose. This hydrolysate was used as fermentation substrate for the biotechnological production of P(3HB) using three different strains of Cupriavidus necator (DSM 428, 531, and 545). By changing the pre-culturing conditions and supplementing nitrogen, the volumetric productivity of C. necator DSM 428 could be increased by more than an order of magnitude. Urea, ammonium sulfate, soy peptone, and casein peptone were tested as nitrogen sources. Soy peptone gave the best results, leading to a twentyfold increase of the volumetric productivity to 0.27 g/L/h. In a direct comparison without any nutrient supplementation, DSM 428, 531, and 545 showed productivities of 0.07, 0.01, and 0.20 g/L/h, respectively. Within two days of fermentation, the most promising strain (DSM 545) produced 11.1 g/L P(3HB) and a cell dry weight of 14.2 g/L, corresponding to a PHA content in dry weight of 78 %. The detoxification of the fermentation substrate using charcoal or laccase did not further improve the fermentation performance, which indicates that a detoxification of the chicory root hydrolysate is not required. To sum up, it can be said that chicory roots are a promising raw material for the production of PHAs through bacterial fermentation.