296 



Mary Davies Swartz, 



The best known member of this group is inulin,i closely associated 

 with which are the four levulans described by Tanret; these seem to 

 be intermediate products between inulin and levulose, all having 

 greater solubility than inulin, but less levo-rotatory power. The 

 other carbohydrates mentioned are also more soluble than inulin, 

 but have higher specific rotation. 



LEVULANASES IN THE VEGETABLE KINGDOM. 



Comparatively few studies have been made upon the action of 

 enzymes on the levulans, and these have been for the most part lim- 

 ited to inulin. Certain micro-organisms as B. Coli communis (295), 

 Clostridium pastorianum (328), and several Schizomycetes, decom- 

 pose inulin, but without any production of sugar. Yeast, according 

 to Tanret (321) does not ordinarily ferment it, but Lindner (308) 

 asserts that certain forms of top yeast change it readily. Levulin 

 is fermented by yeast, according to Levy (307), and triticin, in the 

 course of four or five days, according to Reidmeister (314); but it 

 seems probable that the first changes are due to gradual hydrolysis 

 on standing in water, or to other organisms. 



The effect of vegetable enzymes on these carbohydrates, as far as 

 they have been studied, is shown in the following table: 



(1) Levy (307) 



(2) Reidemeister (314) 



(3) Chittenden (292) 



(4) Harlay (301) 



(5) Reidemeister (314) 



(6) Schmiedeberg (318) 



(7) Dean (293) and others 



(8) Komanos (303) 



Discovery of the best known ferment for any levulan is due to 

 Green (300) who, in 1888, extracted such an enzyme from the tubers 

 of the Jerusalem artichoke {Helianthus tuberosus), and named it "in- 



^For description and early literature see KiHani (302) and Dean (294). 



