RESUMO
Acetic acid bacteria Gluconobacter oxydans subsp. industrius RKM V-1280 were immobilized into a synthetic matrix based on polyvinyl alcohol modified with N-vinylpyrrolidone and used as biocatalysts for the development ofbioanodes for microbial fuel cells. The immobilization method did not significantly affect bacterial substrate specificity. Bioanodes based on immobilized bacteria functioned stably for 7 days. The maximum voltage (fuel cell signal) was reached when 100-130 µM of an electron transport mediator, 2,6-dichlorophenolindophenol, was added into the anode compartment. The fuel cell signals reached a maximum at a glucose concentration higher than 6 mM. The power output of the laboratory model of a fuel cell based on the developed bioanode reached 7 mW/m2 with the use of fermentation industry wastes as fuel.
Assuntos
2,6-Dicloroindofenol/química , Fontes de Energia Bioelétrica , Gluconobacter oxydans/química , Glucose/metabolismo , Polímeros/química , 2,6-Dicloroindofenol/metabolismo , Biocatálise , Células Imobilizadas , Eletrodos , Transporte de Elétrons , Fermentação , Gluconobacter oxydans/metabolismo , Glucose/química , Resíduos Industriais , Oxirredução , Álcool de Polivinil/química , Pirrolidinonas/químicaRESUMO
Receptor elements for biosensors based on Hansenula polymorpha NCYC 495 In yeast cells for ethanol assay were developed using two ways of cell immobilization, i.e., physical adsorption on a glass fiber membrane and covalent binding on a modified nitrocellulose membrane. The linear diapason of ethanol assays for a biosensor based on yeast cells adsorbed on glass fiber was 0.05-1.18; for a biosensor based on yeasts immobilized on a nitrocellulose membrane, 0.2-1.53 mM. Receptor elements based on sorbed cells possessed 2.5 times higher long-term stability. The time response was 1.5 times less for cells immobilized using DEAE-dextran and benzochinone. The results of ethyl alcohol assays using biosensors based on cells immobilized via adsorption and covalent binding, as well as using the standard areometric method, had high correlation coefficients (0.998 and 0.997, respectively, for the two ways of immobilization). The results indicate the possibility to consider the described models of receptor elements for biosensors as prototypes for experimental samples for practical use.
Assuntos
Técnicas Biossensoriais/métodos , Etanol/análise , Pichia/metabolismo , Adsorção , Células Imobilizadas , Colódio , DEAE-Dextrano/metabolismo , Etanol/metabolismo , Vidro , Membranas ArtificiaisRESUMO
The review briefs recent advances in application of biosensors for determining biological oxygen demand (BOD) in water. Special attention is focused on the principles of operation of microbial BOD sensors; the information about biorecognition elements in such systems and the methods used for immobilization of biological components in film biosensors is summarized. Characteristics of some BOD sensor models are considered in detail.
