CNR ExploRA

Articolo in rivista, 2021, ENG, 10.3390/w13070897

Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications

Neda Amanat, Bruna Matturro, Marta Maria Rossi, Francesco Valentino, Marianna Villano, Marco Petrangeli Papini

Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy. Water Research Institute (IRSA-CNR), Via Salaria km 29.300, 00015 Monterotondo RM, Italy. Department of Environmental Sciences, Informatics and Statistics, Ca Foscari University of Venice, Via Torino 155, 30172 Mestre-Venice, Italy.

The use of polyhydroxyalkanoates (PHA) as slow-release electron donors for environmental remediation represents a novel and appealing application that is attracting considerable attention in the scientific community. In this context, here, the fermentation pattern of different types of PHA-based materials has been investigated in batch and continuous-flow experiments. Along with commercially available materials, produced from axenic microbial cultures, PHA produced at pilot scale by mixed microbial cultures (MMC) using waste feedstock have been also tested. As a main finding, a rapid onset of volatile fatty acids (VFA) production was observed with a low-purity MMC-deriving material, consisting of microbial cells containing 56% (on weight basis) of intracellular PHA. Indeed, with this material a sustained, long-term production of organic acids (i.e., acetic, propionic, and butyric acids) was observed. In addition, the obtained yield of conversion into acids (up to 70% gVFA/gPHA) was higher than that obtained with the other tested materials, made of extracted and purified PHA. These results clearly suggest the possibility to directly use the PHA-rich cells deriving from the MMC production process, with no need of extraction and purification procedures, as a sustainable and effective carbon source bringing remarkable advantages from an economic and environmental point of view.

Water (Basel)