Abstract
Studies have been carried out using immobilized Z.mobilis in fluidized-bed bioreactors and have emphasized operation during high productivity and conversion. The bacteria are immobilized within small uniform beads (~1 to 1.5-mm diam) of K-carrageenan at cell loadings of 15-50 g (dry wt)/L. Conversion and productivity were measured under a variety of conditions, including feedstocks, flow rates, temperature, pH, and column sizes (up to 2.5 m tall). Volumetric productivities of 50-120 g EtOH/h-L reactor volume have been achieved. Productivities of 60 g/h-L are demonstrated from a 15% feed with residual glucose concentrations of less than 0.1% and 7.4% EtOH in the tallest fermentor. Among feeds of 10, 15, and 20% dextrose, the 15% gave the highest productivity and avoided substrate inhibition. A temperature of 30°C and pH 5 were the optimum conditions. The ethanol yield was shown to be nearly constant at 0.49 g EtOH/g glucose, or 97% of the theoretical under a variety of conditions and transients. The biocatalyst beads have been shown to remain active for two months. Nonsterile feed has been used for weeks without detrimental contamination. The advantages of this advanced bioreactor system over conventional batch technology are discussed.
Similar content being viewed by others
References
Godia, F., Casas, C., and Sola, C. (1987),Process Biochem. 22(2), 43–48.
Rogers, P. L., Lee, K. J., and Tribe, D. E. (1980),Process Biochem. 15(6), 7–11.
Kuriyama, H., Seiko, Y., Murakami, T., Kobayashi, H., and Sonoda, Y. (1985),J. Ferment. Technol. 63(2), 159–65.
Inloes, D. S., Michaels, A. S., Robertson, C. R., and Matin, A. (1985),Appl. Microbiol. Biotech. 23, 85–91.
Silman, R. W. (1984),Biotech. Bioeng. 26, 247–51.
Bajpai, P. K., and Margaritis, A. (1985),Enzyme Microb. Technol. 7, 462–64.
Scott, C. D., (1983),Biotech. Bioeng. Symp. 13, 287–298.
Cysewski, G. R., and Wilke, C. R. (1978),Biotech. Bioeng. 20, 1421–44.
Samejima, H., Nagashima, M., Azuma, M., Noguchi, S., and Inuzuka, K. (1984),Annals of the NY Acad. Sci. 434, 394–405.
Lee, K. J., and Rogers, P. L. (1983),Chem. Engr. 27, B31-B38.
Grote, W., and Rogers, P. L. (1985),J. Ferment. Technol. 3, 287–90.
Lee, K. J., Skotnicki, M. L., Tribe, D. E., and Rogers, P. L. (1981),Biotech. Lett. 3, 291–96.
Grote, W., Lee, K. J., and Rogers, P. L. (1980),Biotechnol. Lett. 2, 481–486.
Worden, R. M. (1982), “A Kinetic Study of Ethanol Production byZymomonas mobilis,” MS thesis, Univ. of Tennessee, 1982. Also available as ORNL/TM-8722, Martin Marietta Energy Systems, Oak Ridge National Laboratory, Oak Ridge, TN.
Swings, J., and DeLey, J. (1977),Bacteriol. Rev. 41, 1–46.
Davison, B. H., and Scott, C. D. (1986),Biotech. and Bioeng. Symp. 17, 629–632.
Jain, V. K., Toran-Diaz, I., and Baratti, J. (1985),Biotech. Bioeng. 27, 273–279.
Sola, C., Casas, C., Godia, F., Poch, M., and Serra, A. (1986),Biotech. Bioeng. Symp. 17, 519–534.
Scott, C. D. (1987),Ann. NY Acad. Sci. 501, 487–493.
Scott, C. D., and Hancher, C. W. (1976),Biotech. Bioeng. 18, 1393–1403.
Leuenberger, H. G. W. (1972),Arch. Mikrobiol. 83, 347–358.
Fein, Jared E., et al. (1983),Biotech. Lett. 5, pp. 1–6.
Belaich, J. P., and Jenez, J. C. (1965),J. Bacteriol. 89, pp. 195–1200.
Lyness, E., and Doelle, H. W. (1980),Biotechnol. Lett. 2, 549–554.
Laudrin, I., and Goma, G. (1982),Biotechnol. Lett. 4, 537–542.
Luong, J. H. T. (1985),Biotech. Bioeng. 27, 1652–61.
Bajpai, P. K., and A. Margaritis (1986),Biotech. Bioeng. 28, 824–28.
Davison, B. H., and T. L. Donaldson (1987), “Biotechnology Processes: Scale-Up and Mixing,” Ho, C. S., and Oldshue, J. Y., eds., AIChE Publ.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Davison, B.H., Scott, C.D. Operability and feasibility of ethanol production by immobilizedZymomonas mobilis in a fluidized-bed bioreactor. Appl Biochem Biotechnol 18, 19–34 (1988). https://doi.org/10.1007/BF02930815
Issue Date:
DOI: https://doi.org/10.1007/BF02930815