[Effect of various forms of inorganic nitrogen on the biosynthesis of rifamycin B].

To study the influence of various forms of inorganic nitrogen on biosynthesis of rifamycin B, ammonium sulfate, ammonium nitrate, ammonium chloride and sodium nitrate were compared. It was shown possible to use mineral salts containing nitrogen in reduced or oxidized form as fermentation medium components. Sodium nitrate induced early alkalization of the fermentation broth, while ammonium nitrate and ammonium chloride induced its early oxidation. Moreover, the chlorine ions inhibited the antibiotic biosynthesis. All this impaired normal development of the culture. Only ammonium sulfate provided the pH levels of the fermentation broth normal for the antibiotic biosynthesis and the highest levels of the antibiotic production. The positive role of this salt was due to the presence of both the ammonium group and the sulfogroup in the fermentation medium, since addition of the sulfogroup contained in the sulfates or sulfuric acid resulted only in partial increase of the antibiotic yield.