Bacillus subtilis biofilm development in the presence of soil clay minerals and iron oxides

Abstract

Soil: Mineral effects on biofilms The effect of three soil minerals on biofilm production is clarified by research using the common soil bacterium Bacillus subtilis. The mineral composition of soil is known to affect biofilm production, but the mechanisms underpinning minerals’ influences have not been well studied. Peng Cai and colleagues at Huazhong Agricultural University in China, with co-workers in the United States and Singapore, studied Bacillus subtilis growing in the presence of the minerals montmorillonite, kaolinite, and goethite. Their results suggest the minerals, especially goethite, can encourage biofilm formation by promoting the bursting of bacterial cells. The effect of goethite was attributed to the size of its grains being generally smaller than the bacterial cells. By quantifying the effect of these minerals, the research will assist understanding of biofilm formation and the growth and persistence of bacterial populations in soils.