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

Abstract

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.