Biopolymers production from mixed cultures and pyrolysis by-products

Abstract

Polyhydroxyalkanoates (PHAs) production from low value substrates and/or byproducts represents an economical and environmental promising alternative to established industrial manufacture methods. Bio-oil resulting from the fast-pyrolysis of chicken beds was used as substrate to select a mixed microbial culture (MMC) able to produce PHA under feast/famine conditions. In this study a maximum PHA content of 9.2% (g/g cell dry weight) was achieved in a sequencing batch reactor (SBR) operated for culture selection. The PHA obtained with bio-oil as a carbon source was a copolymer composed by 70% of hydroxybutyrate (HB) and 30% of hydroxyvalerate (HV) monomers. Similar results have been reported by other studies that use real complex substrates for culture selection indicating that bio-oil can be a promising feedstock to produce PHAs using MMC. To the best of our knowledge this is the first study that demonstrated the use of bio-oil resulting from fast pyrolysis as a possibly feedstock to produce short chain length polyhydroxyalkanoates.