title: Bio-oil upgrading strategies to improve PHA production from selected aerobic mixed cultures.
abstract: Recent research on polyhydroxyalkanoates (PHAs) has focused on developing cost-effective production processes using low-value or industrial waste/surplus as substrate. One of such substrates is the liquid fraction resulting from pyrolysis processes, bio-oil. In this study, valorisation of bio-oil through PHA production was investigated. The impact of the complex bio-oil matrix on PHA production by an enriched mixed culture was examined. The performance of the direct utilization of pure bio-oil was compared with the utilization of three defined substrates contained in this bio-oil: acetate, glucose and xylose. When compared with acetate, bio-oil revealed lower capacity for polymer production as a result of a lower polymer yield on substrate and a lower PHA cell content. Two strategies for bio-oil upgrade were performed, anaerobic fermentation and vacuum distillation, and the resulting liquid streams were tested for polymer production. The first one was enriched in volatile fatty acids and the second one mainly on phenolic and long-chain fatty acids. PHA accumulation assays using the upgraded bio-oils attained polymer yields on substrate similar or higher than the one achieved with acetate, although with a lower PHA content. The capacity to use the enriched fractions for polymer production has yet to be optimized. The anaerobic digestion of bio-oil could also open-up the possibility to use the fermented bio-oil directly in the enrichment process of the mixed culture. This would increase the selective pressure toward an optimized PHA accumulating culture selection.
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Moita Fidalgo
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Ortigueira
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Freches
authors.affiliation: UBIA, Biomass Science and Technology Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Pelica
authors.affiliation: UBIA, Biomass Science and Technology Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Magarida
authors.initials: M
authors.lastname: Gonçalves
authors.affiliation: UBIA, Biomass Science and Technology Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Benilde
authors.initials: B
authors.lastname: Mendes
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. Electronic address: paulo.lemos@fct.unl.pt.
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Lemos
mesh_terms: D000085:Acetates / Q000378:metabolism; D000332:Aerobiosis; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D002645:Chickens; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D007700:Kinetics; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*
chemical_list: D000085:Acetates; D056804:Biofuels; D005232:Fatty Acids, Volatile; D054813:Polyhydroxyalkanoates