Abstract: The invention relates to a composition for the prevention/reduction of microbe-induced bio-corrosion caused by sulfate-reducing bacteria (SRB) and other microorganisms, especially for the protection of the inner walls of storage tanks for hydrocarbons of all kinds. The aim of the invention is to devise a composition which protects, when used as a corrosion protection compound, microcracks in the coatings of the inner walls of storage tanks for hydrocarbons of all kinds from anaerobic bio-corrosion in an especially effective manner and for as long a period as possible, owing to a locally defined active protection mechanism (depot effect). The composition comprises an epoxy-based, polymeric, cross-linked Al2O3 ceramic particle-containing substrate and a microbistatically effective pyrithione derivative.