Bioconversion of mixed free fatty acids to poly-3-hydroxyalkanoates by Pseudomonas putida BET001 and modeling of its fermentation in shake flasks

Abstract

Background: The paper reports on the utilization of palm kernel oil (PKO) as a low cost renewable substrate for medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) production by Pseudomonas putida BET001. Investigation on the effects of selected key variables on growth, mixed free fatty acids consumption and mcl-PHA production by the bacterial culture in the shaken flask system were carried out along with its kinetic modeling. Results: The biomass production, fatty acids consumption and mcl-PHA production were found favorable when the strain was cultured in mineral medium at pH 6–7, 28°C, aeration surface-to-volume ratio of 0.4 × 106 m-1, 250 rpm agitation rate for 48 h. Mcl-PHA production by this strain showed mixed growth and non-growth associated components as described by Luedeking–Piret kinetic model. Conclusion: The findings of this study provided add to the literature on key variables in for achieving good microbial growth and mcl-PHA production in shake flasks culture. In addition, suitable kinetic model to describe cultivation in this system was also presented.

Keywords

• Biopolymer
• Fermentation
• Medium-chain-length PHA
• Palm kernel oil
• Pseudomonas putida