The invention addresses the problem of developing an environmentally compatible, storable and long-acting agent against phytopathogenic microorganisms, especially fungi, on the basis of defined biological factors. Said problem is solved by an antifungal agent for treating fungal and other microbial and viral infections, which is prepared on the basis of spores of Bacillus amyloliquefaciens plantarum. Representatives of said taxonomic group have the ability to form at least ten different antimicrobial substances which belong to the families of dipeptides (bacilysin), lipopeptides and siderophores (bacillomycin D, fengycin, surfactin and bacillibactin), polyketides (difficidin, bacillaene and macrolactin) and the group consisting of bacteriocins/microcins (amylocyclicin and plantazolicin). The new strain B. amyloliquefaciens plantarum AB101 is characterised by improved persistence in the area of the plant rhizospere and increased effectiveness against the root rot disease ("black scurf") in potatoes caused by Rhizoctonia solani. The bacteriocin amylocyclicin produced from AB101 is a previously unknown bacteriocin having a strong effect against gram-positive bacteria. The invention can be used in plant protection, biotechnology and agriculture.
