A study of the flavin response by Shewanella cultures in carbon-limited environments

作者：Roy Jared N^*; Luckarift Heather R; Lau Carolin; Falase Akinbayowa; Garcia Kristen E; Ista Linnea K; Chellamuthu Privthiraj; Ramasamy Ramaraja P; Gadhamshetty Venkataramana; Wanger Greg; Gorby Yuri A; Nealson Kenneth H; Bretschger Orianna; Johnson Glenn R; Atanassov Plamen

来源：RSC Advances, 2012, 2(26): 10020-10027.

DOI：10.1039/c2ra21727a

Mediated electron transfer has been implicated as a primary mechanism of extracellular electron transfer to insoluble electron acceptors in anaerobic cultures of the facultative anaerobe Shewanella oneidensis. In this work, planktonic and biofilm cultures of S. oneidensis exposed to carbon-limited environments trigger an electrochemical response thought to be the signature of an electrochemically active metabolite. This metabolite was detected via cyclic voltammetry for S. oneidensis MR-1 biofilms. The observed electrochemical potentials correspond to redox potentials of flavin-containing molecules. Chromatographic techniques were then used to quantify concentrations of riboflavin by the carbon-limited environmental response of planktonic S. oneidensis. Further evidence of flavin redox chemistry was associated with biofilm formation on multi-walled carbon nanotube-modified Toray paper under carbon-starved environments. By encapsulating one such electrode in silica, the encapsulated biofilm exhibits riboflavin redox activity earlier than a non-encapsulated system after media replacement. This work explores the electrochemical nature of riboflavin interaction with an electrode after secretion from S. oneidensis and in comparison to abiotic systems.

• 出版日期2012