Intact and permeabilized cells of the yeast Hansenula polymorpha as bioselective elements for amperometric assay of formaldehyde
- 作者：Maria Khlupova ; Boris Kuznetsov ; Olha Demkiv ; Mykhailo Gonchar ; Elisabeth Csö ; regi ; Sergey Shleev
- 关键词：Bioselective analysis ; Formaldehyde ; Biosensor ; Amperometry ; Redox mediator ; Intact and permeabilized cells ; Yeast Hansenula polymorpha
- 刊名：Talanta
- 出版年：2007
- 期刊代码：106_00399140
- 类别：ch
- 出版时间：15 February 2007
- 卷：71
- 期：2
- 页码：934-940
- 文件大小：435 K
摘要
Intact and permeabilized yeast cells were tested as the biorecognition elements for amperometric assay of formaldehyde (FA). For this aim, the mutant C-105 (gcr1 catX) of the methylotrophic yeast Hansenula polymorpha with a high activity of AOX was chosen. Different approaches were used for monitoring FA-dependent cell response including analysis of their oxygen consumption rate by the use of a Clark electrode, as well as assay of oxidation of redox mediator at a screen-printed platinum electrode covered by cells entrapped in Ca-alginate gel. It was shown that oxygen consumption rate of permeabilized cells reached its saturation at 4 mM of FA (23 °C). The detection limit was found to be 0.27 mM. In the presence of redox mediator 2,6-dichlorophenolindophenol (DCIP), the screen-printed platinum band electrode covered by permeabilized cells did not show any current output to FA. In contrast, well-pronounced amperometric response to FA was observed in the case of intact yeast cells in the presence of DCIP. It was shown that current output reached its maximum at 7 mM concentration of FA. The detection limit was found to be 0.74 mM. Obviously, it is necessary to perform a directed genetic engineering of the yeast cells to improve their bioanalytical characteristics in the corresponding biosensors.