The glyoxylate pathway contributes to enhanced extracellular electron transfer in yeast-based biofuel cell.
This study provides a new insight into our understanding of yeast response to starvation conditions (sole acetate as carbon source) and applied polarization and offers important information about the role of the glyoxylate cycle in the carbohydrate synthesis and extracellular charge transfer processes in biofuel cells. The biosynthetic capabilities of yeast C. melibiosica 2491 and the up/down-regulation of the glyoxylate cycle are evaluated by modifying the cellular metabolism by feedback inhibition or carbohydrate presence and establishing the malate dehydrogenase activity and carbohydrate content together with the electric charge passed through bioelectrochemical system. 10mM malate leads to a decrease of the produced quantity of electricity with ca. 55%. At the same time, 24-times lower intracellular malate dehydrogenase activity is established. At polarization conditions the glyoxylate pathway is up-regulated and huge amount of malate is intra-converted into oxaloacetate. The yeasts are able to synthesize carbohydrates from acetate and a part of them is used for the electricity generation. It is recognized that the enhanced charge transfer in acetate fed yeast-based biofuel cell is implemented by secreted endogenous mediator and changes in the cellular surface redox activity depending on the addition of carbohydrate in the medium.
Department of Electrocatalysis and Electrocrystallization, Institute of Electrochemistry and Energy Systems "Academician Evgeni Budevski"- Bulgarian Academy of Sciences (IEES-BAS), Sofia, Bulgaria; Department of Biochemistry and Microbiology, University of Plovdiv, Plovdiv, Bulgaria. Electronic address: y.hubenova@iees.bas.bg.
Yolina
Y
Hubenova
Department of General Pediatrics, Center for Pediatrics, University Clinics, University of Bonn, Bonn, Germany.
Eleonora
E
Hubenova
Department of Hydrogen Systems with Polymer Electrolyte, Institute of Electrochemistry and Energy Systems "Academician Evgeni Budevski"- Bulgarian Academy of Sciences (IEES-BAS), Sofia, Bulgaria.
Evelina
E
Slavcheva
Innovative Centre of Eco Energy Technologies, South-West University "Neofit Rilski", Blagoevgrad, Bulgaria.
Mario
M
Mitov
D000085:Acetates / Q000494:pharmacology; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D002175:Candida / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004563:Electrochemistry; D004579:Electron Transport / Q000187:drug effects; D006038:Glyoxylates / Q000378:metabolism*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*
D000085:Acetates; D006038:Glyoxylates
Acetate; Carbohydrate synthesis, yeast; Charge transfer; Glyoxylate cycle; Microbial fuel cell