Immobilization of growing cells by polyethyleneimine-modified alginate |
| |
Authors: | John J Joung Cavit Akin G P Royer |
| |
Institution: | (1) Amoco Corporation, P.O. Box 400, 60566 Naperville, Illinois |
| |
Abstract: | A unique polymer matrix that is suitable for immobilizing growing cells has been developed. Alginate was chemically modified
with polyethyleneimine (PEI), and the resultant polymer aggregate was evaluated as a cell carrier. Our method of immobilization
depends on reversible gelation of the PEI-modified alginate. Our hypothesis is that immobilized cells grow by dissolving the
surrounding gel matrix; the dissolved polymer adduct is displaced peripherally and gelled again by the influx of calcium ion
from the surrounding fermentation broth, retaining both cells and carrier polymer in the gel beads. Thus, the immobilized
cells gain space for growth by expanding the carrier matrix. The PEI modification offers the following advantages: (1) improved
mechanical strength; (2) improved cell retention; (3) increased catalyst life; (4) ease of pelletization; and (5) an apparent
bacteriostatic capability.
When immobilized yeast cells were applied to a continuous ethanol fermentation, 94% theoretical conversion of glucose to ethanol
was observed, with a reactor productivity of 15–30 g/L/h in a nonsterile reactor. A 3-mo catalyst life and minimal cell washout
were observed. |
| |
Keywords: | Biocatalysis cell immobilization ethanol fermentation polyethyleneimine-alginate yeast |
本文献已被 SpringerLink 等数据库收录! |
|