Addressing the challenge of optimum polyhydroxyalkanoate harvesting: Monitoring real time process kinetics and biopolymer accumulation using dielectric spectroscopy

• Published in: Bioresource technology 2013-04, Vol.134, p.143-150
• Main Authors: Kedia, Gopal, Passanha, Pearl, Dinsdale, Richard M., Guwy, Alan J., Lee, Matthew, Esteves, Sandra R.
• Format: Article
• Language: English
• Subjects: Acetic Acid - pharmacology; Aerobiosis - drug effects; Batch Cell Culture Techniques; Biological and medical sciences; Biomass; Biorefining; Butyric Acid - pharmacology; Computer Systems; Cupriavidus necator - drug effects; Cupriavidus necator - growth & development; Cupriavidus necator - metabolism; Dielectric spectroscopy; Dielectric Spectroscopy - methods; Dielectrics; Electric Capacitance; Fatty Acids, Volatile - analysis; Fermentation - drug effects; Fundamental and applied biological sciences. Psychology; Harvest time; Harvesting; Hydrogen-Ion Concentration - drug effects; Kinetics; Monitoring; Monitors; Optimization; Oxygen - metabolism; Polyhydroxyalkanoates; Polyhydroxyalkanoates - biosynthesis; Polyhydroxyalkanoates production; Real time; Spectroscopy; Volatile fatty acids
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.01.136

Optimising the polyhydroxyalkanoates (PHA) harvesting time from bacterial cells by measuring capacitance in real-time. [Display omitted] ► Dielectric spectroscopy was used for on-line monitoring of PHA production kinetics. ► The tool proved to be able to monitor real time cell growth and PHA production. ► Optimal PHA harvesting time was also able to be determined in real-time. ► The tool was valuable in improving process understanding and optimization. ► Benefits expected in terms of economic and environmental full-scale PHA production. In this study, dielectric spectroscopy was utilised to evaluate and define the optimum harvesting time for polyhydroxyalkanoates (PHA) production. It is essential to harvest PHA at the optimum time during fermentation for maximum yield, otherwise cells start degrading. Two carbon sources (acetic and butyric acids) were used in laboratory based experiments and a number of samples were measured ex situ for PHA production. The real-time measured capacitance in addition of identifying the cells growth phase, it correlated very well with ex situ measured PHA produced within the cells. The probe has proven to be a useful tool to assess process kinetics, to monitor real-time cell growth, PHA produced and defining the optimum harvesting time.