Preparations of Cell Walls from various Micro-organisms and a Comparison of their Lytic Activities with those of

SUMMARY: Dispersion of isolated cell walls of Streptococcus faecalis in washed agar provided an opaque medium on which cell-wall decomposing micro-organisms were isolated from soil. All of the organisms isolated on S. faecalis cell-wall agar were Streptomyces spp. The lytic activities of seven isolates of Streptomyces, S. albus, two strains of Micromonospora chalceae, Micromonospora sp., Nocardia gardneri and three strains of N. corallina, were studied on cell-wall agar media prepared from five Gram-positive and three Gram-negative bacteria and from the yeast Cundida pulcherrima. The three strains of Nocardia corallina showed no lytic activity on any of the cell-wall substrates. All of the actinomycetes tested were without activity on the Gram-negative cell-wall agar media. Most of the actinomycetes produced lysed zones on Gram-positive cell-wall agar and the greatest lytic activities were observed with Bacillus megaterium and Candida pulcherrima cell-wall substrates. Cytophaga johnsonae and two strains of Myxococcus fulvus were lytic on Candida pulcherrima cell-wall agar but no lysis occurred on the bacterial cell-wall agars. Although trypsin lyses certain heat-killed bacteria, in particular those be