Evaluation of Polyhydroxyalkanoates Production by Cupriavidus necator and Burkholderia cepacia Strains Using Sunflower Seed and Oil

Polyhydroxyalkanoates (PHAs) produced from alternative substrates are a promising option for petroleum based plastics substitution, once the synthetic materials exhibit low degradability resulting in their accumulation in natural environments, which causes serious damaging consequences to the planet ecosystems. PHAs are natural polyesters stored intracellularly by some bacteria strains as an energy source under the limitation of essential nutrients for their cellular growth. In this sense, the present study aimed to evaluate the potential of sunflower seed and sunflower oil as substrates for PHA production by Cupriavidus necator IPT 026 and IPT 027, and Burkholderia cepacia IPT 400 and IPT 119 (15 g L −1 of substrate, pH 7.0, 180 rpm, 72 h shake flask cultivation). All strains evaluated were able to produce PHAs using the substrates offered. Among the four analyzed strains, C. necator IPT 026 presented the highest productivity consuming sunflower seed, synthesizing 4.38 ± 0.17 g L −1 of polymer in the cultivation medium. All biopolymers produced were characterized by Fourier Transform Infrared, displaying the typical functional groups of PHAs. All biomaterials revealed to have high thermal stability (T on set ≥ 238 °C), and presented low indexes of crystallinity (C I