PHA Productivity and Yield of Ralstonia eutropha When Intermittently or Continuously Fed a Mixture of Short Chain Fatty Acids

Table 5

Comparison of combined short fatty acid feeding of Ralstonia eutropha in shake flasks.


Parameters	Volatile fatty acid
Parameters	Acetic (5 g L⁻¹)	Butyric (5 g L⁻¹)	Lactic (8 g L⁻¹)	Propionic (5 g L⁻¹)

Maximum cell population (cfu mL⁻¹)	5.70 10^9a	6.17 10^9ab	5.32 10^9a	6.67 10^9b
Fermentation efficiency (%)	70.6^a	95.6^b	70.7^a	68.6^a
Acid utilization rate (g L⁻¹ h⁻¹)	0.048^a	0.041^a	0.080^b	0.046^a
PHA concentration (g L⁻¹)	2.9^ab	4.6^a	2.4^b	4.3^a
Cell dry weight (g L⁻¹)	9.9^ab	14.5^b	6.0^a	14.7^b
PHA productivity (g L⁻¹ h⁻¹)	0.024^ab	0.037^a	0.020^b	0.036^a
PHA content (%)	29.2^a	31.9^a	30.7^a	29.3^a

^a,bMeans within column not sharing common superscript differ significantly (P < 0.05).