The use of NaCl addition for the improvement of polyhydroxyalkanoate production by Cupriavidus necator

• Published in: Bioresource technology 2014-07, Vol.163, p.287-294
• Main Authors: Passanha, Pearl, Kedia, Gopal, Dinsdale, Richard M., Guwy, Alan J., Esteves, Sandra R.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Culture Media; Cupriavidus necator; Cupriavidus necator - growth & development; Cupriavidus necator - metabolism; Dielectric spectroscopy; Dielectrics; Fundamental and applied biological sciences. Psychology; Low cost; Polyhydroxyalkanoate production; Polyhydroxyalkanoates; Polyhydroxyalkanoates - biosynthesis; Productivity; Sodium chloride; Sodium Chloride - chemistry; Strategy; Stress concentration; Stresses; Toxicology; Volatile fatty acids
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.04.068

•NaCl is a low cost and sustainable external stress that can enhance PHA production.•NaCl addition at 9g/l resulted in 30% more and an earlier PHA accumulation.•Addition of 12 and 15g/l NaCl were found to inhibit the production of PHA.•A dielectric spectroscopy probe was able to indicate PHA accumulation in real-time.•The window for maximum accumulation was detected by the probe avoiding polymer loss. External stress factors in the form of ionic species or temperature increases have been shown to produce a stress response leading to enhanced PHA production. The effect of five different NaCl concentrations, namely 3.5, 6.5, 9, 12 and 15g/l NaCl on PHA productivity using Cupriavidus necator has been investigated alongside a control (no added NaCl). A dielectric spectroscopy probe was used to measure PHA accumulation online in conjunction with the chemical offline analysis of PHA. The highest PHA production was obtained with the addition of 9g/l NaCl, which yielded 30% higher PHA than the control. Increasing the addition of NaCl to 15g/l was found to inhibit the production of PHA. NaCl addition can therefore be used as a simple, low cost, sustainable, non toxic and non reactive external stress strategy for increasing PHA productivity.