title: Mechanisms of electron transfer between a styrylquinolinium dye and yeast in biofuel cell.
abstract: In the present study, the influence of the recently synthesized styrylquinolinium dye 4-{(E)-2-[4-(dimethylamino)naphthalen-1-yl]ethenyl}-1-methylquinolinium iodide (DANSQI) on the intracellular processes as well as the electrical outputs of Candida melibiosica 2491 yeast-based biofuel cell was investigated. The addition of nanomolar quantities of DANSQI to the yeast suspension results in an increase of the current outputs right after the startup of the biofuel cells, associated with an electrooxidation of the dye on the anode. After that, the formed cation radical of the dye penetrates the yeast cells, provoking a set of intracellular changes. Studies of the subcellular anolyte fractions show that 1μM dye increased the peroxisomal catalase activity 30-times (1.15±0.06Unit/mg protein) and over twice the mitochondrial cytochrome c oxidase activity (92±5Unit/mg protein). The results obtained by electrochemical and spectrophotometric analyses let to the supposition that the dye acts as subcellular shuttle, on account of its specific intramolecular charge transfer properties. The transition between its benzoid, quinolyl radical and ion forms and their putative role for the extracellular and intracellular charge transfer mechanisms are discussed.
authors.affiliation: Department of Biochemistry and Microbiology, University of Plovdiv, Bulgaria. Electronic address: jolinahubenova@yahoo.com.
authors.forename: Yolina
authors.initials: Y
authors.lastname: Hubenova
authors.affiliation: Department of Organic Chemistry, University of Plovdiv, Bulgaria.
authors.forename: Rumyana
authors.initials: R
authors.lastname: Bakalska
authors.affiliation: Faculty of Medicine, University of Bonn, Germany.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Hubenova
authors.affiliation: Innovative Center of Eco Energy Technologies, South-West University "Neofit Rilski", Bulgaria.
authors.forename: Mario
authors.initials: M
authors.lastname: Mitov
mesh_terms: D015057:1-Naphthylamine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D002176:Candida albicans / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004396:Coloring Agents / Q000378:metabolism* / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D011806:Quinolinium Compounds / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C583707:4-(2-(4-(dimethylamino)naphthalen-1-yl)ethenyl)-1-methylquinolinium; D004396:Coloring Agents; D011806:Quinolinium Compounds; D009243:NAD; D045304:Cytochromes c; D015057:1-Naphthylamine
keywords: Catalase and cytochrome c oxidase activities; Intramolecular charge transfer; Microbial fuel cell; Styrylquinolinium dye; Subcellular shuttle