140 Influence of Low Temperatures lipon Enzymes [March, 



human saliva, and amylase from Aspergillus niger. After the Solu- 

 tion of each variety had been subjected to that temp. for 4-5 min., 

 it retained unaltered its power to hydrolyze starch. 



Inulinase. Pozerski (5) subjected a Solution of inulinase, 

 obtained from Aspergillus niger, to the temp. of liquid air (app. 

 — 191° C.) for 45 min. The inulinase completely retained its 

 power to hydrolyze inulin. 



OxiDASE. Pennington, Hepburn, St. John, Witmer, Stafford 

 and Burrell (10) held, at 0° C, both milk and cream containing 

 formaldehyde (o.i percent) and which were bacteriologically sterile; 

 the milk for 35 days, the cream for 28 days. Analyses were made at 

 weekly intervals. During the entire period of holding, the trikresol 

 oxidase of both the milk and the cream retained its activity. 



Hepburn (11) records the occurrence of oxidases in the crude 

 fat of a chicken held at 0° C. for 15 days after death, and in the 

 crude fat of chickens of known history held hard frozen at — 9.4° 

 to — 12.2° C. for 9 months; and also of birds, whose history prior 

 to freezing was unknown, kept at — 9.4° to — 12.2° C. for periods 

 of 23 and 63 months. 



Peroxidase, The presence of peroxidase in the crude fat of 

 all the chickens mentioned in the preceding paragraph was demon- 

 strated by Hepburn (11). 



Catalase. This enzyme was detected by Hepburn (11) in the 

 crude fat of chickens of known history kept hard frozen for 9 

 months at — 9.4° to — 12.2° C. Pennington and Robertson (3) 

 found that, after eggs had been held at 0° C. for 65 days, the catalase 

 of both the white and the yolk was still active. 



The work of Pennington, Hepburn, St. John, Witmer, Stafford 

 and Burrell (10) shows that the catalase in both milk and cream, 

 rendered bacteriologically sterile by formaldehyde (o.i percent), re- 

 tained its activity during holding at o°C. for as long as 21 days. 



Van Driest (12) reports the presence of catalase in frozen sole, 

 held at — 2° to — 9-5° C, for periods of 19 to 21 days, and in frozen 

 cod kept at — 2° to — 6.5° C. for 30 days. 



Reductase. Hepburn (11) found reductases in the crude fat 

 of chickens subjected to prolonged hard freezing at — 9.4° to 

 — 12.2° C. Simple reductase, which decolorized methylene blue, 

 was found in chickens of known history kept for 9 months, and 



