RT Journal Article
T1 Raw used cooking oil valorization into polyhydroxyalkanoates by mixed microbial cultures: evaluation of one- and two-unit configuration
A1 Ucha Muñoz, Carlota
A1 Martínez Rey, Sara
A1 Correa Galeote, David
A1 Pedrouso Fuentes, Alba
A1 Mosquera Corral, Anuska
A1 Val del Río, Ángeles
K1 Accumulation
K1 Bacterial abundance
K1 Biopolymer
K1 Enrichment
K1 HRT
K1 Nitrogen source
K1 Pilot plant
AB The production of polyhydroxyalkanoates with untreated used cooking oil (UCO) as substrate represents an interesting strategy to valorize this residue into a value-added product. Three sequencing batch reactors (R1, R2, and RA) were operated, using mixed microbial cultures (MMCs) fed with raw UCO. R1 and R2 operated as enrichment units, with withdrawal at the end of the feast and famine phases, respectively. Enrichment was achieved in both within 30 days, reaching similar accumulations of the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) (17.76 wt. % in R1 and 12.47 wt. % in R2). To improve process stability and reduce chemical consumption for pH control, urea was evaluated as nitrogen source, resulting in a reactor less dependent on pH control and increasing PHBV content from 16.7 to 25.7 wt. %. Then, the accumulation unit (RA) was operated in series with R1 to evaluate the maximum PHBV production of the biomass and compare the one-unit (R1) and two-unit (R1 + RA) configurations. Different hydraulic retention times (HRTs) were studied for the one-unit (24 and 48 h) and the two-unit (48 and 96 h) configurations. The best overall performance was observed at an HRT of 48 h in both cases, with similar accumulations (44.8–49.1 wt. % PHBV), yields (230–250 g PHBV/kg UCO) and productivities (0.010–0.013 g PHBV/(L·h)), showing that the one-unit was the best strategy for its operational simplicity. These results demonstrate the feasibility of enriching MMCs to produce PHBV using raw UCO, highlighting the potential of one-unit configuration to perform enrichment and accumulation steps in the same reactor.
PB Elsevier
YR 2026
FD 2026-02-24
LK https://hdl.handle.net/10347/46437
UL https://hdl.handle.net/10347/46437
LA eng
NO Bioresource Technology Volume 448, May 2026, 134291
NO This research was supported by the Spanish Government through the project POLYGO1 [TED2021-130164B-I00 MICIU/ AEI / 10.13039 / 501100011033 / Unión Europea NextGenerationEU / PRTR], the ECOPOLYVER project [ PID2020-112550RB-C21/ AEI / 10.13039/501100011033 & PID2020-112550RB-C22/ AEI / 10.13039/501100011033] and the ALBA project [CNS2022-135142 MICIU/ AEI / 10.13039 / 501100011033 / Unión Europea NextGenerationEU / PRTR]. Alba Pedrouso acknowledges Ramon y Cajal (RYC2023-044762-I) funded by MICIU/AEI/10.13039/501100011033 and ESF+. Carlota Ucha, Sara Martínez-Rey, Alba Pedrouso, Anuska Mosquera-Corral and Ángeles Val del Río belong to a Galician Competitive Research Group (GRC ED431C 2025/19) and CRETUS Research Centre (ED431G 2023/12). The authors thanks to PMA Nutrigrás S.A. for the UCO provided.
DS Minerva
RD 23 may 2026