SLIPPING RIB

Abstract

MTDICALJOI_~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~EIA alkalis.The lipoids contained by bacteria, because of their effect on surface tension, are probably concentrated rouind the periphery of the bacterial cells, and form a protective covering to the organism.This fatty envelope protects tlhenm from proteolytic ferments, but once tllis lhas been removed active proteolysis tales place.Higl ternperatures and dryincg cause a redistribution of tlle lipoid-protein complex, aud tlius, for physical reasons, disturb tlle protective mechanism.rTherefore the antitryptic property of bacteiia depends on totally different factors fromn the antitrypsin of egg wlhite and blood serum.Teale and Bach7 showed that the antitryptic power of egg white wos due to the preseince of a non-diffusible protein substanice whicl is not affected in the dry state by treatmenit witih lipoid solvents.Th''e same observers showe-d that the antitrypsin of blood serum was not dependelnt on the li-poids preselnt.,Although lipoid solvents appear to destroy the antitrypsin of blood serum, they do tllis by coagulating tlle proteins.Drying lhad no effect on tlle antitrypsin of blood seruim, nor was it destroyed by lipoid solvents wlenl precautions were taken to prevent protein coagulation.Tlhe greater resistance of Gram-positive bacilli to lipoid solvents,and Iieat is also capable of explarnation on the basis of the phlysical dispersion of tlle lipoids.E isenberg8 found that staphylococci became Gram-niegative after extraction with ether and that B. coli could be made Gram-positive on treatment with lecithin.Benians9 observed that crushed Gram-positive,organisms are promptly decolorized, and conieluded that the con(lition of the cell wall is the factor determining resistance to Gram's stain.