The aim of our investigations was to make the screening of 21 strains of micromycetes (Penicillium) from the National Collection of Nonpathogenic Microorganisms of the Institute of Microbiology and Biotechnology of the Academy of Sciences of Moldova, in order to establish their antimicrobial effect on the causal agent of American foul brood Paenibacillus larvae. The tested strains were isolated from soil samples taken from the central region of the Republic of Moldova. Malt agar and Czapek

more »

... m served as nutrient mediums for the isolation of micromycetes. Micromycetes cultivation was carried out in the thermostat at the temperature of 28 o C for 14 days. Out of the 21 tested cultures, only 6 strains possessed high antibacterial properties against Paenibacillus larvae, the diameter of inhibition zone of the pathogen ranging from 10.2 ± 1.1 mm to 2.5 ± 2.31 mm. Two strains possessing the most intense antimicrobial activity were selected for subsequent investigations. The diameter of the inhibition zone of Paenibacillus larvae when treated with exometabolites of this two strains constituted 22-23 mm, which is equivalent to the effect of neomycin.