The antimicrobial activity of the culture fluid of Lentinus edodes mycelium grown in submerged liquid culture was tested against
some common bacterial species and Candida albicans. The mycelium-free culture fluid was bacteriostatic against Streptococcus
pyogenes, Staphylococcus aureus and Bacillus megaterium. The substance responsible for the activity was heat-stable, could be
extracted with chloroform and had a molecular weight under 10 000. These characteristics suggested that the component might
be lenthionine, an antibacterial and antifungal sulphur-containing compound. The culture fluid was less toxic to human tissue
culture cells than to microbes. The antibacterial activity and toxicity could not be attributed to the same component. © 2001
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