Biochar and Graphene Oxide as electron mediator for reduction of Fe (III) using Shewanella oneidensis MR-I

Biochar is a charcoal which is a rich carbon. Biochar contains quinones and aromatic structures that facilitate extracellular electron transfer between microbial cells and insoluble minerals. Graphene oxide is a substance with compact structure that can be act as electron mediated in redox process. Iron reducing bacteria (IRB) can employ biochar and graphene oxide as electron shuttles mediator to enhance the Fe (III) reduction activities. The aim of this study is to investigate the effect the biochar produced from coconut frond and graphene oxide on the microbial Fe (III) iron reduction. Different concentration of biochar and graphene oxide are use which is ranging from 5.0 mg/L to 0.0005 mg/L into the M1 minimum media supplemented with glucose as electron donor and Fe (III) hyroxides as electron acceptor inoculated with model IRB strain, Shewanella oneidensis MR-1 and incubated at 30 °C anaerobically The effect of each biochar on the microbial Fe(III) reduction activities were monitored by measuring the concentration of Fe(II), which is the product of Fe(III) reduction, via colometric method using Ferrozine reagent. The results from this study was elucidate how coconut frond biochar and graphene oxide that affect the microbial Fe(III) reduction activities, thus showed effecting the effectiveness of biochar and graphene oxide as electron shuttles for microbial Fe(III) reduction.