@article{mbs:/content/journal/micro/10.1099/00221287-16-1-236, author = "Strange, R. E. and Dark, F. A.", title = "A Cell-wall Lytic Enzyme Associated with Spores of Bacillus Species", journal= "Microbiology", year = "1957", volume = "16", number = "1", pages = "236-249", doi = "https://doi.org/10.1099/00221287-16-1-236", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-16-1-236", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "SUMMARY: Aqueous extracts of disintegrated spores of Bacillus cereus and nonvirulent B. anthracis contained an enzyme which produced visible lysis of the isolated cell walls of vegetative B. cereus. Optimum activity occurred at pH 7–8 in the presence of cobalt or manganese ions (10 p.p.m.) at 58°. Activity was destroyed during heating at 100° for 15 min. The lytic preparation released non-dialysable components containing ae-diaminopimelic acid (DAP), glutamic acid, alanine, amino sugars and glucose. Although lysis was less obvious, the enzyme preparation released similar material from cell walls of other Bacillus species, spore coats of B. megaterium and coats of autoclaved B. cereus spores. Extracts of freshly harvested B. cereus spores were more active than those from spores which had been stored for several weeks at 2°. Extracts from disintegrated spores of B. megaterium had no enzymic activity; the enzyme system was associated with the insoluble spore coat fraction. The action of the enzyme differed from that of lysozyme or glucosaminidase; the reaction products did not give a significant reaction for N-acetylhexosamine and visible lysis proceeded more rapidly with cell walls of B. cereus than with B. megaterium. Possible functions of the enzyme may be to release ‘ spore peptide ’ from the spore coat during germination and to lyse the sporangium and free the spore during sporulation.", }