During the course of search for new antibiotics, the authors isolated a new streptomyces strain No. 772 from a soil sample in Pahlavi, Afghanistan. The taxonomic studies on this strain were carried out and this strain was recognized as being a new species and designated as Streptomyces afghaniensis.

This strain produces a new antibiotic substance, which inhibits markedly the growth of gram positive bacteria. Up to date this new antibiotic is not obtained in a crystalline form, but it was recognized to be a new one through chemical reactions, activities against many bacteria and several animal tests, and named Taitomycin.In this paper the authors present the taxonomic study on S. afghaniensis and process for obtaining the antibiotic.

The authors made a study on the antibiotic substance produced by S. afghaniensis and recognized that it was a new antibiotic, though not obtained in a crystalline form up to date, and designated it as Taitomycin¹⁾. In this paper the physicochemical and biological properties of taitomycin are described.

In the previous papers^1),2), it was reported that the antibiotic substance produced by S. afghaniensis inhibits strongly the growth of gram positive bacteria. It was also observed that from the physicochemical and biological properties of the purified powder, this substance is a new antibiotic and therefore this new antibiotic was named Taitomycin. In this paper the biological properties of taitomycin and the results of the experiments in animals are presented.

Several phenazine derivatives, such as pyocyanin¹⁾, chlororaphin²⁾, iodinin³⁾ and phenazine-α-carboxylic acid^4),5) have been known to be produced by a genus Pseudomonas. Recently, Nakamura^6),7) determined the structure of griseolutein B, an antibiotic produced by Streptomyces griseoluteus, as a phenazine derivative. And also, griseolutein A, the other antibiotic produced by the same organism was shown to be a phenazine derivative.

It has not been known that the genus Streptomyces produces the any other phenazine derivative than grisoelutein A and B. The authors⁸⁾ reported previously that Streptomyces thioluteus and its mutant excrete an yellow pigment into their cultured broth as well as aureothricin and thiolutin. The present report deals with the isolation, crystallization and properties of the pigment and identified it as 1, 6-dihydroxyphenazine.

Maintenant que de nombreuses substances antibiotiques des polyenes ont été découvertes. Mais il n’y a que seulement deux antibiotiques des hexaenes: La flavacide^1),2),3) et la mediocidine⁴⁾. H. Lachevalier et R. A. Pledger⁵⁾ ont isolé 28 souches de Streptomyces, producteur de polyene. Mais 26 souches ont produit heptaene et 2 produit pentaene.

Nous avons isolé, à partir d’un prelevement de terre effectué à Mt. Zinba (Japon), 56 souches de Streptomyces, une de ces Streptomyces que nous avons nommé “Streptomyces No. 963,” qui s’est montrée douée de propriétés antimicrobiennes et se produit antibiotique de hexaene. Les caractéristiques et le procédé qui a donné lieu à l’identification de cette souche seront d’écrites dans d’autres papiers par Mr. M. Arishima.

Nous avons isolé a l’état cristallisé un antibiotique de hexaene, qui inhibit fortement Candida albicans, Cryptococcus neoformans, les bactéries gram positive et les fongiques, extrait des myceliums cultures submergées. Nous le ccnsidérons comme un nouvel antibiotique de hexaene pour ses caractéres physiques, chimiques et biologiques et nous l’avons nommé Cryptocidine pour son activité sur Cryptococcus.