Cell immobilization in κ‐carrageenan for ethanol production

Abstract

A combination of extended Monod kinetics and the diffusional equation was used for evaluating the effectiveness factor of entrapped immobilized cells. Based on the kinetics of Zymomonas mobilis reported in the literature, the numerical results have revealed that the problem of mass transfer diffusional restrictions can be neglected by using small beads (1 mm in diameter) with a corresponding cell loading up to 276 g/L gel. On the basis of the numerical results obtained, the application of immobilized cells for continuous ethanol production was investigated. The kappa-carrageenan method was utilized to entrap Z. mobilis CP4, a potential ethanol producer. A two stage fermentation process has also been developed for ethanol production by the Z. mobilis carrageenan-bound cells. About 90 g/L ethanol was produced by immobilized cells at a total residence time of 1.56 h. The ethanol yield was estimated to be 93% of theoretical. The results obtained in this study also indicated that the control of optimum pH in an immobilized cell column is necessary to enhance the rate of ethanol production.

Lactose Hydrolysis by β-Galactosidase Covalently Immobilized to Thermally Stable Biopolymers

“…This advantage enables the carrageenan gel to be shaped in any form [17]. However, a drawback of carrageenan is its low thermal stability [18] and the lack of active functional groups [19][20][21].…”

Gel Entrapment and Micro-Encapsulation: Methods, Applications and Engineering Principles

“…4: Simulation of biomass concentration profile in a Ca-alginate bead with entrapped S. cerevisiae (Willaert and Baron, 1994). Monod + substrate and D f0 a,(\-a 2 C x ) 2 A, B product inhibition de Gooijer et al, 1991;Wijffelset al, 1991;Wijffels, 1994de Gooijer et al, 1992Wijffels, 1994;Sekietal., 1990Furusaki and Seki, 1992 a A, Comparison to experimental data; B, Internal mass transfer resistance only; C, Internal and external mass transfer resistance; D, Includes overall reactor performance model a ι constant (dimensionless) D, diffusion coefficient in water a 2 constant X biomass Beer and Sweerts, 1989;de Beeretal., 1990Hooijmans et al, 1990aAdlercreutz, 1986Hiemstraetal., 1983Brink and Tramper, 1986bRamakrishna et al, 1991Willaert, 1993Willaert, 1993 and Baron, 1993Hooijmans et al, 1990b, c Chen and Huang, 1988Luong, 1985Melicketal., 1987Sakakietal., 1988Webb et al, 1990Zero order C,F,E,H Krouwel and Kossen, 1980 . (c) Steady-State Modelling Provided cell mass does not vary rapidly, or is fairly uniform, the concentration profiles in a gel matrix with entrapped cells can be simulated using a steady-state model at any point in time.…”

Preparation of Polymer–Carbon Nanotube Composite Materials and Their Applications for Enzyme Entrapment

“…Nonspecific DNA-CNT interactions in water result from the DNA base stacking on the CNT surface, with the hydrophilic sugar-phosphate backbone pointing to the exterior (Zheng et al 2003). Second, biomolecules can be entrapped within a k-carrageenan network (Luong 1985). When enzymes are used for an intended application, they must be "immobilized" to facilitate the product recovery and minimize production cost.…”