Production of an environmentally friendly biodegradable cellulose crystalline nanocomposite based on PHB obtained from Cupriavidus necator for developing the shelf life of food products

The potential of polyhydroxybutyrate (PHB) production by Cupriavidus necator IBRC-M10878 using chicken skin oil as a novel carbon source was investigated to reduce production costs and provide a sustainable alternative to petroleum-based polymers. The synthesized PHB was characterized using GC, GPC, 13 C NMR, FTIR, DSC, TGA, XRD, and MFI analyses. Under optimized conditions, PHB concentration, cell dry weight, volumetric productivity, PHB yield based on substrate consumption, and biomass yield reached 3.52 g/L, 4.82 g/L, 0.05 g/L h, 0.41 g/g, and 0.73 g/g, respectively. The physical and thermal properties of PHB, including melting temperature (169.88 °C), glass transition temperature (4.80 °C), degree of crystallinity (57.80 %), maximum degradation temperature (298.82 °C), and weight-average molecular weight (322.57 kDa) were also determined. A biodegradable nanobiocomposite was developed using PHB as the polymer matrix and cellulose nanocrystals (CNCs) as reinforcing agents (2 %, 5 %, and 6 %) via solvent casting with chloroform. The incorporation of 5 % cellulose nanocrystals into the PHB matrix resulted in improved organoleptic properties, a 12.39 % reduction in contact angle, a reduction in light transmission of up to 65.69 %, a 22.3 % decrease in water vapor transmission rate, and an 18.95 % reduction in oxygen transmission rate. Additionally, tensile strength and Young's modulus increased by 23.3 % and 38.2 %, respectively. These enhancements, particularly in barrier properties, contributed to improved shelf life of food products compared to pure PHB, indicating that this nanobiocomposite is a promising candidate for use in packaging applications. • PHB production using chicken skin oil as a new carbon source was carried out. • Solid state fermentation for PHB production using chicken skin oil was carried out. • The production efficiency of PHB biopolymer related to the substrate was 0.414 g/g. • Loading 5 % of CNC in the PHB strengthened mechanical and barrier properties. • The produced nanocomposite developed shelf life for food products.