Studies on the Fire-Blight Organism, Bacillus amylovorus 25 



containing 0.5 per cent of glycerin, and in similar solutions without 

 glycerin. Ten culture tubes and five checks were used for each con- 

 centration. After fifteen days, tests were made for sugars but none 

 were found. There was no significant loss in the weight of the paper. 



Half of the cultures were continued for another ten days after 2 per 

 cent of toluol had been added. Negative results were again obtained. 

 Two additional tests duplicating the conditions of the first failed to 

 give any indication of the presence of cellulase. 



From these results it must be concluded that cellulase was not secreted 

 under the conditions of the experiment. Histological studies of diseased 

 tissue support the view that Baccillus amylovorus produces little or 

 no cellulase. 



Tests for "cytase, " which according to Haas and Hill (1921) is the 

 enzyme that splits hemicelluloses, were not made. Since Schellenberg 

 (1908) and Zeller (1916) found this enzyme present in phytopathogenic 

 fungi, it would not be surprising to find it in pythopathogenic bacteria. 



. , 7 Glucosidases 



Amygdalase 



Emulsin was formerly supposed to split glucosides such as amygdalin 

 into glucose, benzaldehyde, and hydrocyanic acid. According to Haas 

 and Hill (1921), there are two enzymes which take part in this proc- 

 ess: amygdalase in the first step, and prunase in the second. Maltase 

 also is credited with the power to split amygdalin into glucose and 

 mandelonitrile glucoside, the same as amygdalase. 



Waksman and Davison (1926) used the term emulsins to include all 

 enzymes which are capable of hydrolyzing glucosides and various sugars 

 such as raffinose and stachiose. Emulsin is an enzyme preparation 

 rather than a single enzyme. Oppenheimer (1925) has attempted to 

 divide the emulsins on the basis of the glucosides upon which they act. 



Tests were made with Bacillus amylovorus to determine whether 

 amygdalase or prunase is secrete. I by this organism. Uschinsky's solu- 

 tion was prepared with 1 and 2 per cent of amygdalin replacing the 

 glycerin. Six check tubes and six cultures of each concentration were 

 prepared and incubated at 25° C. for fourteen days. It was apparent 

 throughout tins time that the cultures in the 1-per-cent amygdalin 

 made better growth than did those in the 2-per-cent solution. 



At the end of fourteen days, 2 per cent of toluol was added to half 

 of the tubes, which were stored at about 3° C. The remainder were 

 tested for the reducing sugar glucovse, but none was found. There 

 was no odor of almond to betray the presence of benzaldehyde. Tests 

 for hydrocyanic acid failed to give any indication of the formation of 

 Prussian blue. 



Seven days after these tests were made, the tubes containing the 



