title: Anaerobic granular sludge as a biocatalyst for 1,3-propanediol production from glycerol in continuous bioreactors.
abstract: 1,3-Propanediol (1,3-PDO) was produced from glycerol in three parallel Expanded Granular Sludge Blanket (EGSB) reactors inoculated with granular sludge (control reactor-R1), heat-treated granular sludge (R2) and disrupted granular sludge (R3) at hydraulic retention times (HRT) between 3 and 24h. Maximum 1,3-PDO yield (0.52molmol(-1)) and productivity (57gL(-1)d(-1)) were achieved in R1 at HRTs of 12 and 3h, respectively. DGGE profiling of PCR-amplified 16S rRNA gene fragments showed that variations in the HRT had a critical impact in the dominant community of microorganisms. However, no appreciable differences in the bacterial population were observed between R2 and R3 at low HRTs. Production of H2 was observed at the beginning of the operation, but no methane production was observed. This study proves the feasibility of 1,3-PDO production in EGSB reactors and represents a novel strategy to valorise glycerol generated in the biodiesel industry.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Gallardo
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Faria
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: L R
authors.initials: LR
authors.lastname: Rodrigues
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: M A
authors.initials: MA
authors.lastname: Pereira
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal. Electronic address: madalena.alves@deb.uminho.pt.
authors.forename: M M
authors.initials: MM
authors.lastname: Alves
mesh_terms: D001421:Bacteria, Anaerobic / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D058645:Denaturing Gradient Gel Electrophoresis; D005990:Glycerol / Q000378:metabolism*; D011409:Propylene Glycols / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
chemical_list: D011409:Propylene Glycols; D012336:RNA, Ribosomal, 16S; D012722:Sewage; C041787:1,3-propanediol; D005990:Glycerol
keywords: 1,3-Propanediol; Anaerobic granular sludge; Glycerol; HRT; Microbe community structure