Open Access

Lars HäckerORCiD, Dmytro GolovkoORCiD, Sara Sory, Karsten RebnerORCiD, Daniela Almeida StreitwieserORCiD

• Climate change and the urgent need for decarbonization of the heavy industry demand innovative solutions that transform waste into value. One promising approach is the biological utilization of CO2-rich exhaust gases to produce sustainable materials. The goal of this study was to develop a process strategy for maximizing polyhydroxybutyrate (PHB) production by Cupriavidus necator through optimized nutrient management and real-time in-line process analytics. For this, C. necator was grown in a lab-bioreactor with probes for dissolved oxygen, redox potential, and pH value. The kinetics and metabolic phases were measured using reference analytics such as OD600, HPLC-RID and GC. To validate these observations and accurately identify the end of the growth phase, we employed an in-line flow-through cuvette VIS spectroscopy. We were able to correlate several chemical process parameters to the spectral results of the process analysis technology (PAT). This process analytical approach enables precise control of cultivation conditions, paving the way for efficient PHB production from industrial gas streams.