Abstract
Isolated aspen tissue, when grown in vitro for 3 weeks on agar medium, yielded antimicrobial substances which produced inhibitory zones when the culture plates were inoculated with Fusarium roseum, Saccharomyces cervisiae, Bacillus subtilis, Bacillus cereus, Penicillium, roqueforti, Torula utilis, Sarcina lutea, Flavobacterium aquatile, Pullularia pullulans, and Staphylococcus aureus.