鮫肉の尿素含有量とアンモニヤの生成第1報

抄録

Respectively by the xanthydrol method⁹, ¹²⁾ and the WEBER-WILSON's method, we have determined the amounts of urea and ammonia (calculated from the amounts of volatile basic nitrogen) in 100 grams of the muscle of shark-fishes as shown in Table 1.
When the muscle of Prionace glauca (LINNÉT) is caused to decay at 35°C, the contents of urea was decreased quickly by linear function and after 48 hours all urea was decomposed by the urease of the bacteria. On the other hand, the formation of ammonia was much slower in the early stage of putrefaction as compared to the ammonia calculated from the decreasing amounts of urea, but was more rapidly in the later stage (Fig. 1). At the room temperature of winter (9±2°C), a similar tendency was observed (Fig. 2).
As demonstrated by YAMASAKI¹⁵⁾ and SUMNER¹⁶⁾, we assumed that an intermediate product will be formed in the enzymatic hydrolysis of urea, at least in the limit of this experiment.