614 ENZYME ACTION 



meyer flasks, and the cultures incubated for 3 months at a temperature 

 of 32°C. The fungus makes comparatively slow growth both on hard 

 potato agar and on the carrots. While still in an actively growing 

 condition the fungous mats were removed from the flasks, and, when 

 \ thoroughly dry, were finely ground. 



All the methods followed in the present study are similar to those 

 in the former paper.^ This was done in order to make the results as 

 comparable as possible. 



Esterases. 



The esterase activity of Echinodontium tinctorium was determined 

 by the action of the ground fungous meal on methyl acetate, ethyl 

 acetate, ethyl butyrate, triacetin, and olive oil emulsion. After 21 

 days incubation hydrogen ion concentration determinations of the 

 various enzyme cultures and controls were made and compared. 

 Marked esterase activity occurred when methyl acetate and ethyl 

 acetate were used as substrates, a trace of activity when methyl 

 butyrate was employed, but no apparent activity when triacetin and 

 olive oil emulsion were used as substrates. 



Carhohydrases. 



Carbohydrase activity is, no doubt, the most important and most 

 interesting phase in the study of the physiology of the wood-destroy- 

 ing fungi with reference to enzyme action. The action of the fungous 

 meal was determined on 1 per cent solutions of maltose, lactose, 

 sucrose, raffinose, potato starch, inulin, white fir, filter paper cellulose, 

 and hemicellulose. After varying periods of incubation the enzyme 

 cultures were filtered and 5 cc. samples of the filtrate treated with 

 20 cc. of Fehling's solution. In Table I the average results of two 

 titrations are given as the number of cc. of 0.05 N potassium per- 

 manganate required to oxidize the dissolved copper oxide. The 

 results indicate evident action on all the substrates. 



