Ethanol production from starch hydrolyzates using Zymomonas mobilis and glucoamylase entrapped in polyvinylalcohol hydrogel.
The glucoamylase from Aspergillus niger, immobilized into poly(vinylalcohol) hydrogel lens-shaped capsules LentiKats, was used for simultaneous saccharification and fermentation (SSF) with Zymomonas mobilis in free form. This system was stable in both the repeated batch and continuous mode of SSF. The microorganism was found to adsorb on the capsules with immobilized enzyme. This increased the ethanol productivity of the repeated batch system with 5% w/v of immobilized glucoamylase almost 2.1 times (7.2 g l(-1) h(-1)) compared to free enzyme-free microorganism system (3.5 g l(-1) h(-1)). The continuous SSF with the immobilized glucoamylase (11.5% w/v) tested for 15 days had productivity 10 g l(-1) h(-1), which is comparable to continuous experiments on semi-defined glucose medium (10 g l(-1) h(-1)). These two systems were stable in both glucoamylase activity and microorganism productivity.
Rebros
Martin
M
Department of Biotechnology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, Bratislava 812 37, Slovakia. martin.rebros@stuba.sk
Rosenberg
Michal
M
Grosová
Zuzana
Z
Kristofíková
L'udmila
L
Paluch
Miroslav
M
Sipöcz
Matej
M
D001234:Aspergillus niger / Q000201:enzymology; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry / Q000378:metabolism*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013213:Starch / Q000378:metabolism*; D013997:Time Factors; D017355:Zymomonas / Q000378:metabolism
D004800:Enzymes, Immobilized; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D000431:Ethanol; D011142:Polyvinyl Alcohol; D013213:Starch; D005087:Glucan 1,4-alpha-Glucosidase