title: Preeminent productivity of 1,3-propanediol by Clostridium butyricum JKT37 and the role of using calcium carbonate as pH neutraliser in glycerol fermentation.
abstract: Calcium carbonate was evaluated as a replacement for the base during the fermentation of glycerol by a highly productive strain of 1,3-propanediol (PDO), viz., Clostridium butyricum JKT37. Due to its high specific growth rate (µmax=0.53h-1), 40g/L of glycerol was completely converted into 19.6g/L of PDO in merely 7h of batch fermentation, leaving only acetate and butyrate as the by-products. The accumulation of these volatile fatty acids was circumvented with the addition of calcium carbonate as the pH neutraliser before the fermentation was inoculated. An optimal amount of 15g/L of calcium carbonate was statistically determined from screening with various glycerol concentrations (20-120g/L). By substituting potassium hydroxide with calcium carbonate as the pH neutraliser for fermentation in a bioreactor, a similar yield (YPDO/glycerol=0.6mol/mol) with a constant pH was achieved at the end of the fermentation.
authors.affiliation: Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
authors.forename: Zhao Kang
authors.initials: ZK
authors.lastname: Tee
authors.affiliation: Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. Electronic address: jamal@ukm.edu.my.
authors.forename: Jamaliah Md
authors.initials: JM
authors.lastname: Jahim
authors.affiliation: Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
authors.forename: Jian Ping
authors.initials: JP
authors.lastname: Tan
authors.affiliation: Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
authors.forename: Byung Hong
authors.initials: BH
authors.lastname: Kim
mesh_terms: D002119:Calcium Carbonate; D046972:Clostridium butyricum; D005285:Fermentation; D005990:Glycerol; D006863:Hydrogen-Ion Concentration; D011409:Propylene Glycols
chemical_list: D011409:Propylene Glycols; D002119:Calcium Carbonate; D005990:Glycerol
keywords: 1,3-Propanediol; Calcium carbonate; Fermentation; Isolation; pH neutraliser