Nutrilion Investigations. 291 



MANNANASES IN THE VEGETABLE KINGDOM. 



There is very little literature concerning the action of bacteria upon 

 mannans. Sawamura (267) observed that extracts of Hydrangea pa- 

 niculata, used in the manufacture of Japanese paper, which contain 

 mannan (along with galactan and araban) , became liquefied on stand- 

 ing. In bacteriological studies with extracts of this plant, and of 

 roots of Conophallus konjaku, he found that only B. mesentericus vul- 

 gatus dissolved these mannans. The action was greatly facilitated, 

 and sugar formation increased if a certain wild yeast, in itself inactive, 

 were present. Traces of a similar enzyme seem to occur in B. prodi- 

 giosus. 



In his studies of the action of moulds on hemicelluloses, Schellen- 

 berg (269) found that the seeds of Ruscus aculeata, which yield almost 

 exclusively mannose (237-240), were attacked only by Penidllium 

 glaucum. Herissey (253), using pure cultures and water extracts of 

 cultures of Aspergillus niger (grown on media rich in mannose and ga- 

 lactose to incite the development of mannanase and galactanase) , with 

 suitable antiseptics and controls, obtained mannose — and galactose 

 — from seeds of Ceratonia siliqua and Gleditschia triacanthus, and an 

 abundant yield of mannose from salep; similar results were obtained 

 with Aspergillus f us cus. 



As early as 1862, Sachs (266) observed the change of the thickened 

 cell- walls of the date endosperm into sugar during germination. The 

 cytases producing this change in 'reserve-cellulose' were later care- 

 fully investigated by Reiss (264), Brown and Morris (230), Newcombe 

 (261), Griiss (251), and others. Still more recently, Bourquelot and 

 Herissey have made many studies on the specific characteristics of 

 these plant enzymes. An exhaustive review of the literature on man- 

 nans and the action of enzymes upon them has been published by 

 Herissey (253), consequently this subject will only be reviewed very 

 briefly here. 



Griiss (251) has demonstrated that the solution of the date embryo 

 {Phoenix dactylifera) is due to a ferment, the product of whose activ- 

 ity is galactan and mannose. Effront (241) (in 1897) attributed the 

 solution of the albumen of carob seeds (called by him caruban) to a 

 "caroubinase," but thought that the product of its activity was not 

 identical with the products of hydrolysis; in 1899, however, Bourque- 

 lot and Herissey (233) showed the possibility of obtaining mannose 

 by the action of a soluble ferment derived from these seeds, which 

 they called "seminase." Shortly afterwards, a similar enzyme was 



