Change of resistance to lysozyme and ultrasonic disintegration of the mycelium of Streptomyces griseus under the influence of chelating agents and polyvalent cations

Mycelia of Streptomyces griseus strain No. 52-1 from a 2-day submerged culture pretreated with ethylenediaminetetraacetic acid (EDTA) were digested with lysozyme. The sensitivity of younger vegetative hyphae to lysozyme increased while that of older reproductive hyphae remained almost unchanged.EDTA or borate pretreatment increased resistance to ultrasonic disintegration in the case of 96-h mycelia from submerged culture. EDTA was most effective at a concentration of 10−5 M.The enhanced resistance to ultrasonic disintegration can be reversed by Mg2+ and Al3+ in a concentration of 10−5 M, while Ca2+ ions are ineffective.These results suggest the existence of a polyvalent-ion-dependent layer in the cell wall of streptomycetes. Such a layer would be exterior to the mucopeptide layer. Its thickness changes during the life cycle and it is most prominent in younger vegetative hyphae.

[Mineral salts requirements of Corynebacterium sepedonicum (Spiek. & Kott.) Skapt. & Burkh]

The mineral requirements of Corynebacterium sepedonicum (Spiek. & Kott.) Skapt. & Burkh., were studied in a medium containing seven amino acids, three vitamins, dextrose, and tris buffer. The organism does not grow in a mineral-free medium. Potassium phosphate monobasic and potassium phosphate dibasic are required in concentrations of 1.2 × 10−3 and 2.8 × 10−3 mole per liter respectively. Ammonium phosphate monobasic inhibits the growth. Potassium can be replaced by calcium when H3PO4 is used as a source of PO4---. Magnesium as MgCl2∙6H2O in concentration of 2 × 10−3 mole per liter is required for good growth but does not affect the morphology of the organism as reported for other bacteria. Manganese as MnSO4>∙H2O and iron as Fe(SO4)2(NH4)2∙6H2O, in concentrations of 10−3 and 10−6 mole per liter respectively, are not essential but stimulate the growth when added to potassium phosphate (KH2PO4 and K2HPO4) and magnesium. Copper, nickel, cobalt, aluminum, and zinc were found to be inhibitory.

Calcergy inhibited by calciphylactic challengers

The subcutaneous calcification effected in the rat at sites directly treated with calcergens, such as lead acetate, CeCl(3), CaCl(2), and KMnO(4), is inhibited by simultaneous local application of various calciphylactic challengers, but not by many other compounds.