Constancy of characteristics in the streptomycetes.

Sanchez-Marroquin, A. (University of Mexico, México D.F.). Constancy of characteristics in the streptomycetes. J. Bacteriol. 83:1183-1192. 1962.-A total of 150 Streptomyces strains isolated from soil was studied during a 3-year period in regard to constancy and variation of the following characteristics: sporophore micromorphology, color of the aerial and substrate mycelium, surface configuration of the spores, assimilation of carbon compounds, production of H(2)S and melanoid pigment, and reduction of nitrates. A remarkable constancy in the following characteristics was found: (i) sporophore micromorphology when only three of the seven morphological series of Pridham et al. were developed on tomato paste-oatmeal agar or yeast extract-malt extract agar; (ii) color of the aerial mycelium if only four fundamental colors are distinguished (white to cream or buff shades; yellow to orange or brown; pink to cinnamon, red or pinkish tan to lavender; and green to gray or blue); (iii) surface configuration of the spores divided in two types (smooth and warty to spinous or hairy); (iv) assimilation of five carbon compounds (arabinose, xylose, rhamnose, raffinose, and mannitol); (v) production of H(2)S on Difco peptone-iron agar supplemented with 0.1% Difco yeast extract; and (vi) production of melanoid pigment on peptone agar, giving similar results to those of the H(2)S test. Color of the substrate mycelium, size and shape of the spores, and reduction of nitrates should be used only as complementary data in the species descriptions, owing to their inconsistency and unreliability.