title: The Influence of Dopants on the Effectiveness of Alginate Beads in Immobilized Cell Reactors.
abstract: Zymomonas mobilis immobilized in doped calcium alginate (Ca-alginate) was successfully employed for the production of ethanol in an immobilized cell reactor. Polyethylene oxide and F127 dimethacrylate were evaluated as potential dopants for Ca-alginate beads to decrease lag time and increase initial ethanol yield. The influence of the type and concentration of the dopant on the effectiveness of the microbe immobilized in Ca-alginate beads to produce ethanol was studied, and results were compared to the widely used 2 % Ca-alginate with no dopants, which acted as control. Immobilized cell reactors that were operated using beads doped with 0.25 % polyethylene oxide (PEO) reached an ethanol yield of ∼70 % in 24 h, which was significantly higher than an ethanol yield of 25 % obtained for the control reactor operated using undoped Ca-alginate beads. This study shows that the use of water-soluble dopants can potentially reduce the lag phase and thus improve the initial production yield of immobilized cell reactors, likely due to an increase in porosity and diffusion rate of the doped beads.
authors.affiliation: Chemical and Materials Engineering, University of Nevada, Reno, 1664 North Virginia St. MS0388, Reno, NV, 89557, USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Nordmeier
authors.affiliation: Chemical and Materials Engineering, University of Nevada, Reno, 1664 North Virginia St. MS0388, Reno, NV, 89557, USA. dcc@unr.edu.
authors.forename: Dev
authors.initials: D
authors.lastname: Chidambaram
mesh_terms: D000464:Alginates / Q000737:chemistry; D019149:Bioreactors; D018914:Cells, Immobilized / Q000737:chemistry*; D000431:Ethanol / Q000138:chemical synthesis*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D014867:Water / Q000737:chemistry; D017355:Zymomonas / Q000737:chemistry*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D014867:Water; D000431:Ethanol; D011092:Polyethylene Glycols; D020723:Glucuronic Acid
keywords: Ca-alginate; FDMA; Immobilized cell reactor; PEO