title: Production of 1,3-Propanediol by Clostridium butyricum VPI 3266 in continuous cultures with high yield and productivity.
abstract: The effects of dilution rate and substrate feed concentration on continuous glycerol fermentation by Clostridium butyricum VPI 3266, a natural 1,3-propanediol producer, were evaluated in this work. A high and constant 1,3-propanediol yield (around 0.65 mol/mol), close to the theoretical value, was obtained irrespective of substrate feed concentration or dilution rate. Improvement of 1,3-propanediol volumetric productivity was achieved by increasing the dilution rate, at a fixed feed substrate concentration of 30, 60 or 70 g l(-1). Higher 1,3-propanediol final concentrations and volumetric productivities were also obtained when glycerol feed concentration was increased from 30 to 60 g l(-1), at D=0.05-0.3 h(-1), and from 60-70 g l(-1), at D=0.05 and 0.1 h(-1).30 g l(-1) of 1,3-propanediol and the highest reported value of productivity, 10.3 g l(-1) h(-1), was achieved at D=0.30 h(-1) and 60 g l(-1) of feed glycerol. A switch to an acetate/butyrate ratio higher than one was observed for 60 g l(-1) of feed glycerol and a dilution rate higher than 0.10 h(-1); moreover, at D=0.30 h(-1) 3-hydroxypropionaldehyde accumulation was observed for the first time in the fermentation broth of C. butyricum.
authors.affiliation: Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200, Porto, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: González-Pajuelo
authors.forename: J C
authors.initials: JC
authors.lastname: Andrade
authors.forename: I
authors.initials: I
authors.lastname: Vasconcelos
mesh_terms: D000085:Acetates / Q000032:analysis; D000447:Aldehydes / Q000032:analysis; D018533:Biomass; D002087:Butyrates / Q000032:analysis; D046972:Clostridium butyricum / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005985:Glyceraldehyde / Q000031:analogs & derivatives / Q000032:analysis; D005990:Glycerol / Q000378:metabolism; D007218:Industrial Microbiology; D011407:Propane / Q000032:analysis; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D000085:Acetates; D000447:Aldehydes; D002087:Butyrates; D003470:Culture Media; D011409:Propylene Glycols; C047158:3-hydroxypropionaldehyde; D005985:Glyceraldehyde; C041787:1,3-propanediol; D005990:Glycerol; D011407:Propane