Abstract
A program of screening a wide range of fungi for ability to "ferment" glucose and various agric. wastes and surpluses in submerged culture revealed that spp. of Ustilago were capable of rapid dissimilation of carbohydrates with the production of a complex substance appearing as long needle-like optically active crystals in the culture mixture, fats and sterols, and a range of new antibiotic substances designated as Ustizeain A, B, etc. The crystalline material and the fats and sterols together constitute the major metabolic products. The antibiotics are stable and effective in vitro against Gram-positive bacteria such as Bacillus subtilis and Mycobacterium smegmatis; against Gram-negative Brucella bronchiseptica; and against many fungi including species of Aspergillus niger and A. flavus groups, certain penicillia, Verti-cillium, and many other Fungi Imperfecti.