BACTERIAL AUTOLYSIS 569 



The customary aseptic precautions were taken and toluol 

 added to the suspensions. After a vigorous shaking the bottles 

 were incubated at 37°C., with the exception of Ic which was placed 

 in the ice box, and the autolysis allowed to proceed. The results 

 are shown in chart 11. 



A glance at the chart shows that the 3 incubated samples 

 underwent hydrolysis to the extent of from 20 to 40 per cent of 

 the biuret-giving substances of the bacterial cells. The amino 

 nitrogen determinations, however, presented peculiar anomalies. 

 In la and lb there were sufficient increases to account for the 

 hydrolysis, but Ic and Id actually showed a decrease, the dis- 

 crepancy in Id being very considerable. One-third of the entire 

 biuret-giving material disappeared without yielding any increase 

 in amino nitrogen as estimated by these tests. Furthermore 

 the amino nitrogen present in the beginning seemed to decrease 

 by about half. The ratio is nearly the same for Ic, which was 

 kept at ice box temperature, where one-sixteenth of the biuret- 

 giving substances were lost, with an accompan>dng decrease 

 in amino nitrogen of about one-eighth. No satisfactory explana- 

 tion can be offered for these apparent discrepancies. That 

 these curves represent, in the main, the actual course of the 

 reaction is supported by the general agreement of the many 

 readings, not all of which have been plotted on this chart. It 

 would seem that the first reading on the amino nitrogen curve 

 for Id is plotted a little too high. This point was obtained from 

 the average of two out of three detemiinations which gave gas 

 volumes of 1.60, 1.74 and 1.80 cc. of nitrogen, respectively. 



Conductivity determinations were also made from time to 

 time of samples taken from the test suspensions. The results 

 are expressed in the insert in chart 11. A slight but uniform 

 increase in conductivity was noted throughout the experhnent. 



To explain the anomalous behaviour of suspensions Ic and 

 Id the hypothesis was advanced that we are concerned here 

 with some vigorous deamidizing action whereby the amino acids 

 lost their identity as fast as they were formed. It was too late, 

 however, to study changes in ammonia content, but no evidence 

 could be adduced that there had been any considerable forma- 



