title: Scanning electrochemical microscopy based evaluation of influence of pH on bioelectrochemical activity of yeast cells - Saccharomyces cerevisiae.
abstract: In this research scanning electrochemical microscopy was applied for the investigation of immobilized yeast Saccharomyces cerevisiae cells. Two redox mediators based system was applied in order to increase the efficiency of charge transfer from yeast cells. 9,10-phenanthrenequinone (PQ) was applied as a lipophilic redox mediator, which has the ability to cross the cell's membrane; another redox mediator was ferricyanide, which acted as a hydrophylic electron acceptor able to transfer electrons from the PQ to the working electrode of SECM. Hill's function was applied to determine the optimal pH for this described SECM-based system. The influence of pH on cell viability could be well described by Hill's function. It was determined that at pH 6.5 the PQ has a minimal toxic influence on yeast cells, and the kinetics of metabolic processes in cells as well as electron transfer rate achieved in consecutive action of both redox mediators were appropriate to achieve optimal current signals.
authors.affiliation: Vilnius University, Faculty of Chemistry, Department of Physical Chemistry, Naugarduko 24, 03225 Vilnius, Lithuania; State Research Institute Centre for Physical Sciences and Technology, Laboratory of Bio-nanotechnology, Savanoriu 231, 02300 Vilnius, Lithuania. Electronic address: arunas.ramanavicius@chf.vu.lt.
authors.forename: A
authors.initials: A
authors.lastname: Ramanavicius
authors.affiliation: Vilnius University, Faculty of Chemistry, Department of Physical Chemistry, Naugarduko 24, 03225 Vilnius, Lithuania; Vilnius Gediminas Technical University, Department of Mechatronics and Robotics, J. Basanaviciaus 28, 03224 Vilnius, Lithuania.
authors.forename: I
authors.initials: I
authors.lastname: Morkvenaite-Vilkonciene
authors.affiliation: Vilnius University, Faculty of Chemistry, Department of Physical Chemistry, Naugarduko 24, 03225 Vilnius, Lithuania.
authors.forename: A
authors.initials: A
authors.lastname: Kisieliute
authors.affiliation: Vilnius University, Faculty of Chemistry, Department of Physical Chemistry, Naugarduko 24, 03225 Vilnius, Lithuania.
authors.forename: J
authors.initials: J
authors.lastname: Petroniene
authors.affiliation: Vilnius University, Faculty of Chemistry, NanoTechnas - Centre of Nanotechnology and Materials Science, Department of Analytical and Environmental Chemistry, Naugarduko 24, 03225 Vilnius, Lithuania.
authors.forename: A
authors.initials: A
authors.lastname: Ramanaviciene
mesh_terms: D018914:Cells, Immobilized; D004566:Electrodes; D004579:Electron Transport / Q000187:drug effects; D005292:Ferricyanides / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D050296:Microbial Viability / Q000187:drug effects; D064347:Microscopy, Electrochemical, Scanning; D010084:Oxidation-Reduction; D010616:Phenanthrenes / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D005292:Ferricyanides; D010616:Phenanthrenes; C007931:hexacyanoferrate III; C005399:9,10-phenanthrenequinone
keywords: Bioelectrochemistry; Electron transfer; Microbial biofuel cells; Scanning electrochemical microscopy; Yeast cells