title: Mediated amperometric biosensors for lactic acid based on carbon paste electrodes modified with baker's yeast Saccharomyces cerevisiae.
abstract: Carbon paste electrodes modified with baker's yeast Saccharomyces cerevisiae (a source of flavocytochrome b(2)) were investigated as amperometric biosensors for lactic acid. Phenazine methosulphate was used as a mediator. The optimal operational conditions of the electrodes were: an operating potential 0.0 V, solution pH 7.2, concentration of phenazine methosulphate in solution 0.2 mM. A linear range in the dependence of the current responses on the concentration of lactic acid was up to 1 mM. The suitability of the electrodes for determination of lactic acid in milk and dairy products such as kefir and yoghurt was tested. The yeast cells in the paste remained viable at least for 1 month.
authors.affiliation: Institute of Chemistry, Gostauto 9, LT-01108, Vilnius, Lithuania. rasagar@takas.lt
authors.forename: R
authors.initials: R
authors.lastname: Garjonyte
authors.forename: V
authors.initials: V
authors.lastname: Melvydas
authors.forename: A
authors.initials: A
authors.lastname: Malinauskas
mesh_terms: D001681:Biological Assay / Q000295:instrumentation* / Q000379:methods; D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D003573:Cytochrome b Group / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019344:Lactic Acid / Q000032:analysis* / Q000737:chemistry; D008839:Microelectrodes; D019255:NADPH Oxidases / Q000737:chemistry*; D009824:Ointments; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
chemical_list: D003573:Cytochrome b Group; D009824:Ointments; D019344:Lactic Acid; D002244:Carbon; C036888:cytochrome b558; D019255:NADPH Oxidases