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

Abstract EN

The research described in this present study was part of a larger effort focused on developing a dual substrate, dual fermentation process to produce Polyhydroxyalkanoate (PHA).

The focus of this study was developing and optimizing a strategy for feeding a mixture of SCFAs (simulated ARF) and maximizing PHA production in a cost-effective way.

Three different feeding strategies were examined in this study.

The substrate evaluated in this study for the growth phase of R.

eutropha was condensed corn solubles, a low-value byproduct of the dry-mill, corn ethanol industry.

The culture was grown to high cell densities in nitrogen-supplemented condensed corn solubles media in 5 L bioreactors.

The overall growth rate of R.

eutropha was 0.2 h−1.

The 20 mL ARF feeding every 3 h from 48 to 109 h strategy gave the best results in terms of PHA production.

PHA productivity (0.0697 g L−1 h−1), PHA concentration (8.37 g L−1), and PHA content (39.52%) were the highest when ARF was fed every 3 h for 61 h.

This study proved that condensed corn solubles can be potentially used as a growth medium to boost PHA production by R.

eutropha thus reducing the overall cost of biopolymer production.