Conductometric biosensor for ethanol detection based on whole yeast cells.
The quantification of ethanol in alcoholic beverages was performed by yeast cell-based conductometric biosensor. A membrane with yeast cells immobilized in 2% Ca-alginate gel was attached on gold planar electrodes. Changes in conductivity due to the specific consumption of ethanol by yeast cells were registered by the computer-controlled sensor system. The response time of the constructed microbial sensor was less than 5 min, linearity (in a logarithmic scale) was observed in the range of 5-100 mM alcohol concentration. It was established that pH value in their region from 5 to 8 did not influence the levels of initial signal. The increase of a buffer capacity in the sample results in the decrease of the biosensor output. The minimal detectable level of ethanol was 1 mM and the relative standard deviation appeared to be 10-12% for 15 repeated assays. When the system was operated and stored at 20-25 degrees C, the biosensor response was stable for only 3 days. However, when the microbial sensor was stored at 4 degrees C, the system was stable up to 12 days. Good correlation between the results obtained by a conductometric cell-biosensor and gas chromatograph was observed.
Institute of Molecular Biology and Genetics, Academy of Science of Ukraine, Kiev.
Y I
YI
Korpan
S V
SV
Dzyadevich
V P
VP
Zharova
A V
AV
El'skaya
D000434:Alcoholic Beverages / Q000032:analysis*; D015374:Biosensing Techniques; D002021:Buffers; D002175:Candida / Q000378:metabolism*; D003217:Conductometry; D000431:Ethanol / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D016015:Logistic Models
D002021:Buffers; D000431:Ethanol