Potential of the lactate-driven polyhydroxyalkanoates (PHA) production via mixed microbial culture

Fabiano Asunis

First

;Luca Attene

Second

;Giorgia De Gioannis

Penultimate

;Aldo Muntoni

Last

2024-01-01

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Abstract

The study investigates polyhydroxyalkanoates (PHA) production from lactic acid-rich substrates via mixed microbial cultures (MMC) using lactic acid rather than traditional volatile fatty acids (VFAs) as precursors. A MMC capable of producing PHA directly from a synthetic lactic acid solution was selected through the feast and famine approach by applying an organic loading rate (OLR) of 1.2 gC L-1 and an uncoupled strategy for nutrient feeding. Preliminary accumulation tests showed that the selected biomass was able to reach up to 50% of PHAs accumulation by dry weight, primarily as hydroxybutyrate (HB). These findings underscore the potential of using lactic acid, potentially derived from dark fermentation of lactose-containing agro-industrial residues like cheese whey, for cost-effective and sustainable PHA production