Microbial synthesis of polyhydroxybutyrate from glycerol: Gluconeogenesis, molecular weight and material properties of biopolyester
Article first published online: 8 JUN 2012
Copyright © 2012 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 109, Issue 11, pages 2808–2818, November 2012
How to Cite
Tanadchangsaeng, N. and Yu, J. (2012), Microbial synthesis of polyhydroxybutyrate from glycerol: Gluconeogenesis, molecular weight and material properties of biopolyester. Biotechnol. Bioeng., 109: 2808–2818. doi: 10.1002/bit.24546
- Issue published online: 24 SEP 2012
- Article first published online: 8 JUN 2012
- Accepted manuscript online: 7 MAY 2012 07:22AM EST
- Manuscript Accepted: 26 APR 2012
- Manuscript Revised: 17 APR 2012
- Manuscript Received: 8 MAR 2012
- molecular weight;
- Cupriavidus necator;
Glycerol is considered as an ideal feedstock for producing bioplastics via bacterial fermentation due to its ubiquity, low price, and high degree of reduction substrate. In this work, we study the yield and cause of limitation in poly(3-hydroxybutyrate) (PHB) production from glycerol. Compared to glucose-based PHB production, PHB produced by Cupriavidus necator grown on glycerol has a low productivity (0.92 g PHB/L/h) with a comparably low maximum specific growth rate of 0.11 h−1. We found that C. necator can synthesize glucose from glycerol and that the lithotrophical utilization of glycerol (non-fermentative substrate) or gluconeogenesis is an essential metabolic pathway for biosynthesis of cellular components. Here, we show that gluconeogenesis affects the reduction of cell mass, the productivity of biopolymer product, and the molecular chain size of intracellular PHB synthesized from glycerol by C. necator. We use NMR spectroscopy to show that the isolated PHB is capped by glycerol. We then characterized the physical properties of the isolated glycerol-based PHB with differential scanning calorimetry and tensile tests. We found that although the final molecular weight of the glycerol-based PHB is lower than those of glucose-based and commercial PHB, the thermal and mechanical properties of the biopolymers are similar. Biotechnol. Bioeng. 2012; 109: 2808–2818. © 2012 Wiley Periodicals, Inc.