114 CHEMISTRY OF BACTERIA AND THEIR PRODUCTS 



autolysis results in the destruction by the enzymes of the endotoxins 

 themselves. Rettger^^ found among the autolj^ic products of bac- 

 teria, leucine, tyrosine, basic substances, and phosporic acid. Under 

 favorable conditions complete autolysis can occur in Iwo to ten 

 days. 



Brieger and Mayer'^ found that at room temperature (15° C.) 

 practically no autolysis occurs with typhoid bacilli in distilled water, 

 and the soluble products thus obtained are quite non-toxic, although 

 if injected into animals they give rise to the production of agglu- 

 tinins and bacteriolysins. Bertarelli'® has used the products of au- 

 tolysis of cholera vibrios successfully in the production of immunitj^ 

 and states that the products of autolysis consist largely of nucleins. 



It is probable that in every culture bacteria are constantly being 

 destroyed, either by their own enzymes or by the proteolytic enzymes 

 of the other bacteria. Some bacteria are much more rapidly auto- 

 lyzed than others, cholera vibrios, colon, typhoid, and dj^sentery 

 bacilli being rapidly digested, while streptococci, staphylococci and 

 tubercle bacilli are very little and slowly autolyzed. In general, the 

 Gram-positive organisms resist autolysis longest, but pneumococci 

 autolyze readil}'. 



Conradi,'^ who has shown that certain products of autolysis of tis- 

 sues are bactericidal, believes that also in cultures powcrfulh' bacteri- 

 cidal substances are produced through autoh'sis of the bacteria. This 

 he thinks, accounts for the decrease in numbers of living bacteria that 

 always sets in after a short period of growth on artificial media; but 

 there is much doubt as to these substances being of any considerable 

 importance in the body.^^ It has been found by Turro'^ that ex- 

 tracts from various tissues containing autolytic enzymes can digest 

 bacterial cells. ^^ It is very possible that the endotoxins contained 

 within such pathogenic bacteria as typhoid and cholera are liberated 

 through digestion of the bacteria, either by autolysis or by the en- 

 zymes of the leucocytes and tissues of the organism that they have 

 infected. These, and a number of other bacteria, produce no soluble 

 toxins that diffuse from the cells as do diphtheria and tetanus toxin, 

 and it is difficult to explain liie toxic effects these bacteria produce 

 without assuming that their iiitrnccllular toxins are liberated in some 

 such way. It is also cjuite probable that th(> enzymes found in fil- 

 trates from bacterial cultures arc liberated from tlu> liacterial cells 



1^ Jour. Mod. Research, 1904 (13), 79. 



" Deut. med. Woch., 1904 (30), 980. 



"Cent. f. Hiikt., l'.)()r> (3S), 5SI. 



" Miinch. mod. Woohon.sclir., 1905 (ry2) 1701. 



'8Soo iMJkinnii, ('out. f. Hiikt., 190() (41), 3(17; I'assini, AVion. klin. Woch., 

 190<) (19), (127. 



'" Cent. f. liukt., 1902 (32), 10."). 



*" Si^;wurl, (Arl). ii. d. i'liMi. Inst. Tiil)inK<'n, 1902 (3), 277) found tl.at trypsin 

 and poi),siri (witliout acid) do not injuro liviufi; antluax bacilli. 



