Production and Characterization of Biopolymer from Food Waste Using Pseudomonas putida

Abstract

This study tested polyhydroxyalkanoate (PHA) production by usingPseudomonas putida KT2440 in a 5 L lab-scale bioreactor, employing an A cell dry mass concentration of 8.69 ± 0.45 g/L was achieved with a volatile fatty acid (VFA) removal efficiency of 81.75 ± 3.08%. Remarkably, this study achieved the highest PHA mass fraction of (34.81 ± 1.67%). Analysis revealed that poly(3-hydroxybutyrate) (PHB) contributes 83.6 to 86.1% of total PHA followed by poly(3-hydroxyhexanoate) (PHHx) (6.6–8.6%) and poly(3-hydroxy-2-methylvalerate) (PH2MV) (4.9–8.3%). Thermogravimetric analysis showed that PHA polymer started degrading at a temperature of 150 °C with maximum polymer weight loss occurring at approximately 270 °C. Differential scanning calorimetry revealed two peaks corresponding to the melting temperature of the polymer: 140.6, and 154.87 °C. This suggests that the resulting PHA polymer was a blend of different copolymers. This outcome is poised to advance the development of unified PHA production methods within a circular bioeconomy, enhancing both economic and environmental advantages.