( 107 ) 



of lompcralin'c proxod llial tlio fal-spliKiuLi' oir/yino of tlio f:;r<)ii|) ol' 

 the melting' Hiiorcscents is able to resist veiy liiü,li (omperatures. 



The (piantity of lipase which is still active after heating' at a fuiven 

 teiïi|)eratiire and for a tixed time can he (piantitatively estimated 

 hv titration of the fatty acitls splittod olf from the fat hy this lipase. 



By means of fatted tubes the quantity of lipase still active in the 

 culture can be com])uted by comi)arison with more or less heated 

 pi-eparatioiis as the degree of decoloration of the fat in the tubes 

 corres|)onds with the vigoni' of the lipase preparations, proxided 

 their alkalinity be the same. 



The tifst experiments on the decomposition of the lipase by the 

 action of high temperatures were made at 75"^ (J. and were con- 

 ducted as follows. 



In a water-bath of 75° C. sterile test-tubes were placed tilled with 

 .10 ci\P of a culture containing lipase. The niveau in the tube> was 

 about 3 cAI. below that of the water-bath. 



After 2 minutes the liquid in the tubes has adopted the tempera- 

 ture of the water-bath, so that from that moment the heating is 

 reckoned to begin. The lieating of the culture li(pnd in the series 

 of test-tubes lasted respectively 10, 20, 30, 40, 50 and BO minutes; 

 the contents were then, after quickly cooling, poured over into a 

 fatted tube which was sul)sequently kept at 30° C. foi- 24 hours. 



When comparing the intensity of the decoloration of the fat in 

 the tubes we could slate that the lipase was only slightly decom- 

 posed. Even healing of an hour at 75° C. caused but a slight decrease 

 of activity of Iho lipase. Analogous experiments at 84° 85°(*. 

 showed that after an hour's heating a considerable portion of the 

 lipase had still remained active; after 40 irdnutes, howe\er, a 

 distinct decrease of the action of the enzyme could be stated. 



These facts show already that the lipase of the group of B. jhior- 

 f'sci'iis H.qui'fnclriis resists higher temperatures than other enzymes, 

 such as diastase, catalase, urease, trypsine, etc., all of which aie 

 decomposed after being heated during 3t) minutes at 75'^' ( '. 



The following e\|)oriments will pi'ove tiiat the eii/ynie of the 

 melting Ibioi'escenis resists still considerably higher tempci-alui-es. 



HMtimi of th.(' lli)((si' from lKi° 07°. 



On 13 Mav 1911 a series of tubes with cidlnre liipiid were placed 

 in a \valei--balli at l)ti° — 97°. After a fixed time llicy were (piickly 

 cooled and the li(piid was poured inio faded tubes. Aftei' 24 hours 

 at 30° the aclion on the fat wa^ staled. 



