Calcium and the Biological Activities of Two Streptomyces Species Isolated from the Rhizosphere of Soybean Plants PDF

Keywords

calcium chloride, calcium nitrate, soybean

Abstract

Careful examination of the characteristics of both organisms revealed that we were dealing with Streptomyces violochromogenes and Streptomyces glaucescens. Calcium chloride decreased the permeability of both organism as indicated by the low total nitrogen content of their media compared to the controls. Small doses of calcium nitrate suppressed the permeability of S. violochromogenes and increased that of S. glaucescens, whereas the larger doses were stimulatory for both organisms. Calcium chloride increased the accumulation of nitrogen in the biomass of both organisms. Calcium nitrate had similar effects on S. violochromogenes only without affecting S. glaucescens. The stimulatory effects of calcium gradually faded with increasing the concentration. Calcium chloride increased the proteolytic activity in S. glaucescens media only at the larger doses whereas calcium nitrate suppressed the proteolytic activity in S. glaucescens media. The cellulolytic activity of both organisms was suppressed by calcium but amylases were initiated in S. glaucescens media. Those of S. violochromogenes were arrested with the lower levels of calcium but the larger doses restored or stimulated their activity