Eugene L. Dulaney

Hydroxylation of Steroids, Principally Progesterone, by a Strain of Aspergillus Ochraceus

The ability of certain species of Aspergillus to transform progesterone to lla-hydroxyprogesterone has been reported by the Upjohn (7) and Squibb groups (4) and has been observed in these laboratories. We find that the lla-hydroxy derivative usually is transformed further to 6/3,1 ladihydroxyprogesterone. Some cultures, however, were found to introduce secondary hydroxyls to lla-hydroxyprogesterone at positions other than carbon 6. These findings as well as data characterizing the lla-hydroxy and 6/2,1 la-dihydroxy derivatives of progesterone will be reported later (2). In the present communication are reported our studies of progesterone transformation by a strain of A. ochraceus and particularly the effect of Zn++ on introduction of the 6/?-hydroxyl to lla-hydroxyprogesterone.

The human tumor-egg host system. II. Discovery and properties of a new antitumor agent, hadacidin.

Summary A new crystalline antitumor agent, hadacidin, has been discovered in fermentation broths of Penicillium frequentans Westling. The human tumor-embryonated egg system was used to guide fermentation and isolation studies. Against HAD #1 the tumor ID50 of hadacidin is about 3 mg per egg. Hadacidin is active also against HEP #3 and A-42 in the embryonated egg. On a weight basis, hadacidin has about the same range of activity as azaserine and 6-mercaptopurine but has only one per cent the activity of the alkylating agent, triethylene melamine.

INDUCED MUTATION AND STRAIN SELECTION IN SOME INDUSTRIALLY IMPORTANT MICROORGANISMS

Variations in imperfect fungi pose problems in taxonomy that have been with us since study of these organisms began and that will concern us as long as such study continues. Solution of these problems is of paramount importance to students of fungus physiology who are now probing into the biochemistry of fungi whose taxonomy and nomenclature are obscure, to say the least. Fortunately, we now have workable systems in the common genera, Aspergillus30 and Penicillium.23 The genus Fusarium no longer seems so ponderous and unwieldy owing to the work of Snyder and Hansen.26p 27, 28 Nkergaard’s treatment of Alternuria is an excellent foundation for further work with this common genus.17 One group that is now in dire need of a rational approach is the Actinomycetes. The genus Streptomyces, in particular, would seem to be a promising mistress to some young mycologist willing to devote to her the best years of his life. Such a union should be quite fruitful. It is not the object of this paper, however, to discuss the problems and pitfalls involved in studies of variability as related to taxonomy and natural relationships; but a plea is made here for an experimental approach to such problems. Continuing descriptions of taxons without prior experimentation and without a full knowledge of the whole biology of the organisms in question, where this factor can be explored, will lead only to further confusion. The inherent variability that often has been so perplexing to many investigators offers hope to others. Variation in morphological or phenotypical characters are mere expressions of differences and variations in the biochemistry of the organisms. These biochemical activities are under genetic control, and it is now clear that this variability can be increased by various means. It is the use of natural and induced variation in some organisms of industrial importance that will be the subject of this paper. When one is attempting to increase the yield of a product elaborated by an organism, two general pathways are open. We are not concerned here with improvements in purification and recovery. The first of these involves study and improvements of the fermentation environment. The second lies in obtaining superior producing organisms. In the first pathway are included all factors external to the organism; e.g., aeration, agitation, pH, temperature, precursors, nutrients, etc. Once the combination of conditions optimum for maximum production is obtained, only the second pathway is left as a means of increasing production. That is, an organism capable of synthesizing more of the compound in question must be obtained. Herein lies much of the essence of industrial microbiology. The discovery of an organism capable of a desired biochemical activity, the search for its required optimum conditions; then a search for a superior organism which is then studied to determine the optimum conditions for production.

Observations on Streptomyces Griseus. VI. Further Studies on Strain Selection for Improved Streptomycin Production

Through the use of ultraviolet light, x-rays and natural selection, mutants were obtained that were capable of producing markedly higher streptomycin broth potencies than the starting culture. The ...

A Note on the Culture of Dipodascus Uninucleatus in Defined Media

During a recent survey of fungi for the production of vitamins, it was found that Dipodascus uninucleatus failed to grow in certain media. Good growth, however, was obtained in a medium contain? ing 5.0 grams of glucose and 10.0 grams of Difco yeast extract per liter of distilled water. When three-day old mycelium grown in this glucose-yeast extract broth was washed with sterile distilled water and used to inoculate a vitamin free medium, only sparse growth resulted. The mycelium constituting the sparse growth in the vitamin free medium was likewise washed and used to inocu?

In vitro and in vivo Activity of 3-(1-Methyl 1-5-Nitro-2 Imidazolylmethylideneamino)-2-OxazoIidinone against Pasteurella

Furazolidone was more active than 3-(1-methyl)-5-nitro-2-imidazolyl-methylideneamino)-2-oxazolidinone (MABN) against a series of 34 isolates of Pasteurella and 11 of Yersinia (forme