Abstract
In nature there are several thousand different higher fungi species, but not all of them have mycelia whose characteristics are in optimum combinations. Many of these fungi cannot be subjected to submerged cultivation, do not assimilate a large range of substrates, synthesize only a small amount of protein, and have an unsatisfactory degree of protein assimilation and other limitations.
The V. Kolarov Higher Institute of Agriculture in Plovdiv, Bulgaria, has isolated strains of higher fungi mycelia that combine the most desirable biological, technological, and nutritive characteristics. A strain called PS-64 is especially promising. It was isolated in 1964, patented, and registered in the world collection of micro-organisms. PS-64 is available for license.