Biopolymer production using volatile fatty acids as resource: Effect of feast-famine strategy and lignin reinforcement.

Abstract

The present study aimed to investigate the biopolymer production using VFA s as carbon source through feast and famine strategy in a sequencing batch reactor. Famine condition with nutrients and oxygen limitation resulted in high polyhydroxybutyrate yield (PHB: 2.65\xa0±\xa00.012\xa0g/L; 0.36\xa0±\xa00.015 gPHB/gVFA) than feast mode (0.26\xa0±\xa00.02\xa0g/L; 0.034\xa0±\xa00.013 gPHB/gVFA). Repeated batch operations induced substrate consumption, wherein acetate utilization was high in both the conditions (feast: 83%, famine 74%) followed by butyrate (feast: 74%, famine 72%). Besides, high biomass concentration was also observed in feast condition (3.45\xa0±\xa00.14\xa0g/L VSS), while oxygen and nutrients limitation in famine mode regulated the carbon use for biomass growth (2.46\xa0±\xa00.15\xa0g/L VSS). Further, PHB grafting with lignin (3% and 5%) exhibited increased thermal stability than pristine PHB. Biopolymer production using VFA s as carbon source and utilization of lignin as functional filler for strengthening PHB offer lignin valorization also wider its applications specifically in the biomedical field.