The effect of carbon source supplementation on the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Cupriavidus necator

The objective of the present study was to investigate the ability of Cupriavidus necator to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) on various carbon sources in batch cultivation. These results show that C. necator produces poly-3-hydroxybutyrate from single carbon sources. The highest poly-3-hydroxybutyrate (P(3)HB) content was achieved at growth on fructose in the exponential growth phase. The maximum yield of the P(3)HV content was obtained when fructose was mixed with acetate. The highest content P(3)HB-co-(3)HV was also achieved by C. necator when we supplied C-excess and N- and P-normal conditions. These results indicate that C. necator accumulates high polyhydroxyalkanoates (PHA) content by depleting these elements in the culture medium. Nitrogen and phosphorus limitation has no significant effect on the PHA production, whereas C-excess leads to an increase in PHA formation of up to 92% PHAs of cell dry weight after growth on 5 g/L acetate and 40 g/L fructose. (C) 2011 International Union of Biochemistry and Molecular Biology, Inc. Volume 58, Number 3, May/lune 2011, Pages 203-211. E-mail: hunesi@modares.ac.ir, hunesi@yahoo.com