Improved selectivity of microbial biosensor using membrane coating. Application to the analysis of ethanol during fermentation.
A ferricyanide mediated microbial biosensor for ethanol detection was prepared by surface modification of a glassy carbon electrode. The selectivity of the whole Gluconobacter oxydans cell biosensor for ethanol determination was greatly enhanced by the size exclusion effect of a cellulose acetate (CA) membrane. The use of a CA membrane increased the ethanol to glucose sensitivity ratio by a factor of 58.2 and even the ethanol to glycerol sensitivity ratio by a factor of 7.5 compared with the use of a dialysis membrane. The biosensor provides rapid and sensitive detection of ethanol with a limit of detection of 0.85 microM (S/N=3). The selectivity of the biosensor toward alcohols was better compared to previously published enzyme biosensors based on alcohol oxidase or alcohol dehydrogenases. The biosensor was successfully used in an off-line monitoring of ethanol during batch fermentation by immobilized Saccharomyces cerevisiae cells with an initial glucose concentration of 200 g l(-1).
Tkac
Jan
J
Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, SK-842 38, Bratislava, Slovak Republic. jantk@ifm.liu.se
Vostiar
Igor
I
Gorton
Lo
L
Gemeiner
Peter
P
Sturdik
Ernest
E
D018441:Biofilms; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D000431:Ethanol / Q000032:analysis* / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology; D005292:Ferricyanides / Q000737:chemistry; D020600:Gluconobacter oxydans / Q000378:metabolism*; D005947:Glucose / Q000032:analysis / Q000378:metabolism; D008567:Membranes, Artificial; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D020099:Coated Materials, Biocompatible; D005292:Ferricyanides; D008567:Membranes, Artificial; C007931:hexacyanoferrate III; D000431:Ethanol; D005947:Glucose