The addition of copper accelerates the corrosion of steel via impeding biomineralized film formation of Bacillus subtilis in seawater

•Bacillus subtilis can induce biomineralized film on the steel surface.•Bacillus subtilis provides anticorrosion activity via biomineralization.•The addition of Cu to the steel impedes biomineralized film formation.•Cu accelerates corrosion of steel in the medium with Bacillus subtilis.