Most people wouldn’t think of eating moldy bread. However, bread mold may have a more safe and useful purpose. Researchers have discovered that red bread mold may hold the key to creating sustainable materials for use in rechargeable batteries.
Geoffrey Gadd and colleagues at The University of Dundee in Scotland have shown that, for the first time, the fungus Neurospora crassa (N. crassa) can transform manganese into a mineral composite with electrochemical properties.
We have made electrochemically active materials using a fungal manganese biomineralized process. The electrochemical properties of the carbonized fungal biomass-mineral composite were tested in a supercapacitator and a lithium-ion battery, and it (the composite) was found to have excellent electrochemical properties. This system therefore suggests a novel biochemical method for the preparation of sustainable electrochemical materials.
Their study was recently reported in the Cell Press journal, Current Biology. Many efforts have been made to improve lithium ion batteries or the performance of supercapacitators using alternative electrode materials. However, few had considered fungi in the manufacturing process.
Gadd and his colleagues are not strangers to studying the merits of fungi. They have studied the ability of fungi to transform metals and minerals in useful ways. For instance, in earlier studies they showed that fungi could stabilize toxic lead and uranium. This led them to wonder if fungi could offer a useful alternative for the preparation of electrochemical materials.
We had the idea that the decomposition of such biomineralized carbonates into oxide might provide a novel source of metal oxides that have significant electrochemical properties.
In their recent study, Gadd and his colleagues incubated N. crassa in a media amended with urea and managanese chloride and observed the result. Long-branching filaments became biomineralized and/or enveloped by minerals in various formations. What remained after was a mixture of carbonized bromais and manganese oxide. Further study showed that they have ideal electrochemical properties for use in Supercapacitators or lithium-ion batteries.
Gadd and his colleagues continue to explore the use of fungi in producing potentially useful metal carbonates. They are also interested in investigating such processes for the biorecovery of valuable or scarce metal elements in other chemical forms.
Who would have thought that a moldy piece of bread could wield such power?