Trace elements and the synthesis of vitamin B12 by Streptomyces olivaceus.

Study of the requirement of trace elements for the streptomycetes has often led to contradictory results (Woodruff, 1947; Spilsbury, 1948; Johnstone & Waksman, 1948). This is mostly due to the difficulty in preparing a truly basal medium and also because such requirements vary with the medium employed (Thornberry & Anderson, 1948). The streptomycete Streptomyces olivaceus is one of the few micro-organisms producing significant amounts of vitamin B12 (Hall, Benedict, Wiesen, Smith & Jackson, 1953; Hester & Ward, 1954; Pfeifer, Vojnovich & Heger, 1954). It was therefore thought pertinent to make a comparative study of the effect of supplementation of a synthetic basal medium for S. olivacewu with various trace elements, singly or in combination, on the growth of mycelia and the synthesis of the vitamin.