Characteristics of the formation of substances by various microorganisms that stimulate levorin biosynthesis

: Production specific properties of substances stimulating levorin biosynthesis by various microorganisms were studied. It was noted that substances activating the biosynthesis of levorin were produced by various species of yeast-like fungi. Filtrates of the fermentation broths of bacteria, yeasts or filamentous fungi did not contain substances increasing the antibiotic synthesis. Filtrates of the fermentation broth of yeast-like fungi increased also the synthesis of polyenic antibiotics, such as mycoheptin and amphotericin and suppressed production of nystatin.