Influence of Divalent Metal Ions on Biofilm Formation by Bacillus subtilis

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. The wild strain of B. subtilis 168, the protease-deficient strain of B. subtilis BRB14, and the regulatory mutants of B. subtilis 168 degU and B. subtilis 168 ccpA were examined for their ability to form biofilms under stress conditions—with elevated concentrations of divalent metal ions (Ca2+, Mg2+, Mn2+, and Zn2+), as well as in the presence of ethylenediaminetetraacetic acid (EDTA). It was shown that regulatory mutants are more resistant to the addition of divalent metal ions than wild and protease-deficient strains. At the same time, the introduction of EDTA reduces the level of biofilm formation by all strains on average by 50%