The Adaptive Formation of Levansucrase by a Species of

SuMMARY: Levansucrase in the corynebacterium studied is apparently an adaptive enzyme. Its optimal formation is dependent on the presence of an inducer (sucrose) and an organic nitrogen source. High nitrogen concentrations increase growth rate and sucrose hydrolysis and significantly decrease levansucrase formation. The pH activity curve nf the levansucrase studied is asymmetric and the optimal pH value for its activity is 7.0. These findings suggest that this levansucrase differs from other levansucrases so far described. In a preliminary note (Henis & Aschner, 1954), levan formation by a species of Corynebacterium was described. Maximal yield of levan was obtained in 2 medium composed of 0.1 yo (w/v) K,HPO, and 10 yo (w/v) sucrose in tap water. Only unwashed organisms grown on ordinary nutrient agar could serve as inoculum since washed organisms lost most of their levan-synthesizing ability. It was found later that by the addition of small amounts of certain organic nitrogen compounds ( peptone, casein hydrolysate, glutamic acid) the levan-synthesizing ability of washed organisms could be regained. The purpos