Nov. 12, 192 1 



Pectinase Produced by Different Species of Rhizopus 373 



inoculation purposes but which had not supported a fungous growth. 

 Maceration by the enzym in the solution and in the mycelium was carried 

 out at a temperature of 40° C. for all the species. Before the addition 

 of the raw sweet-potato disks the solutions and suspensions of the my- 

 celium were held for one hour at 40° in order to bring them to the tem- 

 perature at which maceration was to take place. 



A/o^o,sa<s 

 r/?/T/c/ 



Af/C/?OSPORUS 

 A//(9/?/0/9A/iS 



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Fig. I. — Graph showing the time required by the different Rhizopus species to completely macerate 

 sweet-potato disks by the enzym in the solution on which the fungi had grown for three days; also the 

 comparative rate of maceration in the three experiments. 



Maceration with the mycelium was carried out by the use of 0.5 gm. 

 ground in sand and suspended in 25 cc. of water. All the sweet potato 

 disks (i mm. thick and 1.5 cm. in diameter) required for maceration in 

 the solution on which the fungus grew and in a water suspension of the 

 mycelium were cut from a single potato for an entire experiment of all 

 the species. pJxism 



