Mechanistic stratification in electroactive biofilms of Geobacter sulfurreducens mediated by pilus nanowires.

ABSTRACT: Electricity generation by Geobacter sulfurreducens biofilms grown on electrodes involves matrix-associated electron carriers, such as c-type cytochromes. Yet, the contribution of the biofilm's conductive pili remains uncertain, largely because pili-defective mutants also have cytochrome defects. Here we report that a pili-deficient mutant carrying an inactivating mutation in the pilus assembly motor PilB has no measurable defects in cytochrome expression, yet forms anode biofilms with reduced electroactivity and is unable to grow beyond a threshold distance (∼10 μm) from the underlying electrode. The defects are similar to those of a Tyr3 mutant, which produces poorly conductive pili. The results support a model in which the conductive pili permeate the biofilms to wire the cells to the co

SUBMITTER: Steidl RJ 

PROVIDER: S-EPMC4974642 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature