Phage Problems in the Streptomycin Fermentation

SUMMARY

Effective measures for the control and eradication of the phage contamination depend upon strict sanitary precautions throughout the laboratories and fermentation areas and mainly upon the development of cultures immune to the action of the phage.

The end result of the virus infection in the fermentation tanks is usually a characteristic loss of viscosity, diminution or absence of mycelial growth, little or no streptomycin, the presence of a dark brown soluble pigment and the presence of the phage.

The action of phage in a sensitive culture of S. griseus brings about a variety of colony types which are strikingly different in morphological, cultural, and biochemical characteristics. These varying types among the surviving population are comparable to mutants produced by the action of ultraviolet light, X-rays, and nitrogen mustard gas. With the development of phage-immune strains of S. griseus, not only was the phage eliminated but also the streptomycin yields were significantly increased.

Of the various Actinomycetes cultures tested, strains of Streptomyces olivaceus, S. griseolus and S. viridis were sensitive to the phage as well as S. griseus. Therefore, the S. griseus phage is of a polyvalent nature, being able to attack and lyse four or more different species of Streptomyces.

The mechanism of action which determines the lysis of the spores and mycelium of the fungus S. griseus and the formation of plaques is dependent on the availability of free water in the medium which will help in the diffusion of the phage and in the penetration and lysis of the cells by the phage.²

The writer wishes to acknowledge appreciation for the assistance of Mr. Ralph Hill, Mrs. Anna Mae Cottingham. Mrs. Mary Spargo, and Mrs. Verna Schulenberg, to Mr. James Burns who performed all the streptomycin and vitamin B₁₂ assays, and to Mr. Gabor B. Levy for the photographic work.