Bioactive compounds obtained fromCoriolus versicolor (Trametes versicolor (L.: Fr) Lloyd, 1920.) mushrooms cultivated
in a stirred-tank bioreactor were tested to determine their antimicrobial potential. Extracellular polysaccharides
were isolated from the fermentation broth by ethanol precipitation. A methanol extract was prepared
from mycelium. The cultivation conditions applied during the fermentation process provided for significant
biomass 6.63 ± 0.31 g dry weight L−1 and yield of extracellular polysaccharides (EPS) (0.74 ± 0.12 g L−1).
Microscopic analyses revealed that the mycelium grew predominately in the formof fluffy pellets. The methanol
extract demonstrated very good activity against all the tested Gram-positive bacteria. Bacillus spizizeni
and Staphylococcus epidermidis were the most sensitive strains (minimum inhibitory concentration
(MIC) b0.3125 mg mL−1). Among the Gram-negative bacteria, Yersinia enterocolitica had the lowest
MIC value, 5 mg mL−1. Microbicidal activity of mycelia methanol extract was established in seven out of
ten tested Gram-negative bacteria strains with minimum bactericidal concentration (MBC) values ranged
from 20 to 40 mg mL−1. Enterococcus faecalis and Staphylococcus aureus showed higher sensitivity to the
extracellular polysaccharides (MIC values 2.5 mg mL−1). FTIR analysis revealed a more complex chemical
composition of the methanol extract compared to EPS, which might explain the better antibacterial activity
of the methanol extract.