title: Propionic acid production in glycerol/glucose co-fermentation by Propionibacterium freudenreichii subsp. shermanii.
abstract: Propionibacterium freudenreichii subsp. shermanii can ferment glucose and glycerol to propionic acid with acetic and succinic acids as two by-products. Propionic acid production from glucose was relatively fast (0.19 g/Lh) but gave low product yield (~0.39 g/g) and selectivity (P/A: ~2.6; P/S: ~4.8). In contrast, glycerol with a more reduced state gave a high propionic acid yield (~0.65 g/g) and selectivity (P/A: ~31; P/S: ~11) but low productivity (0.11 g/L h). On the other hand, co-fermentation of glycerol and glucose at an appropriate mass ratio gave both a high yield (0.54-0.65 g/g) and productivity (0.18-0.23 g/L h) with high product selectivity (P/A: ~14; P/S: ~10). The carbon flux distributions in the co-fermentation as affected by the ratio of glycerol/glucose were investigated. Finally, co-fermentation with cassava bagasse hydrolysate and crude glycerol in a fibrous-bed bioreactor was demonstrated, providing an efficient way for economic production of bio-based propionic acid.
authors.affiliation: William G. Lowrie Department of Chemical & Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Zhongqiang
authors.initials: Z
authors.lastname: Wang
authors.forename: Shang-Tian
authors.initials: ST
authors.lastname: Yang
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D005990:Glycerol / Q000737:chemistry / Q000378:metabolism*; D002365:Manihot / Q000737:chemistry; D011422:Propionates / Q000737:chemistry / Q000378:metabolism*; D011424:Propionibacterium / Q000378:metabolism*
chemical_list: D056804:Biofuels; D011422:Propionates; D002244:Carbon; D002482:Cellulose; C027433:bagasse; D005947:Glucose; C029658:propionic acid; D005990:Glycerol