Multiple bioanalytical method based residual biomass prediction in microbial culture using multivariate regression and artificial neural network

Optical density (OD) based measurements cannot be a reliable proxy for residual biomass concentration in polyhydroxyalkanoate (PHA) accumulating microbial culture, as cell size and morphology change during growth. In this study, four independent analytical methods i.e., OD measurement at 540 nm and 600 nm, tetrazolium reduction assay, and intracellular protein estimation were adopted to model residual biomass growth in Cupriavidus necator. The inter-day variation of calibration slope for residual biomass was significant (p