Date seed characterisation, substrate extraction and process modelling for the production of polyhydroxybutyrate by Cupriavidus necator

•The feasibility of using waste date seeds for PHB production is demonstrated and modelled.•A yield of PHB on substrate consumed of 0.46 was achieved at a PHB accumulation of 73%.•Reduction of nitrogen and oxygen availability increase PHB accumulation.

Poly-3-hydroxybutrate (PHB) is a biodegradable polymer synthesised via bacterial fermentation as a means of storing carbon and energy under unbalanced growth conditions. The production cost of petroleum-based plastics is currently lower than that for biopolymers, and the carbon source is the most significant contributor to biopolymer production cost.A feasibility study to assess the suitability of using a date seed derived media as an alternative for PHB production under various stress conditions was investigated. Results include fructose extraction from date seeds and a mass transfer model to describe the process, demonstrating that the high nutrient content of date seeds makes them a promising raw material for microbial growth and that a meaningful amount of PHB can be produced without supplementation. Maximum dry cell weight and PHB concentrations were 6.3 g/l and 4.6 g/l respectively, giving a PHB content of 73%, when an initial fructose concentration of 10.8 g/l was used.