291 
Vines, — The Proteases of Plants, 
examined. There is, to begin with, an elaborate investigation by 
Butkewitsch ( 3 ) into the digestive action of certain of the lower Fungi 
[Aspergillus niger , Penicillium glaucum , and species of Mucor , M, stolonifer, 
M. racemosus , M. Mucedd) upon proteids. The Fungi in question were 
cultivated, in previously sterilized vessels, on a substratum consisting of 
proteid matter (Witte-peptone or fibrin) either with or without cane-sugar, 
together with a small proportion of suitable mineral ingredients acidified 
with phosphoric acid. The duration of an experiment varied from five 
days to over a month. The results show that these Fungi can peptolyse 
Witte-peptone, with formation of leucin and ty rosin, and can proteolyse 
fibrin, thus confirming the observations of earlier observers such as 
Malfitano ( 4 ) and others. A remarkable feature of the proteolysis effected 
by Aspergillus was the formation of a large proportion of ammonia (NH 3 ), 
though it was much smaller in the presence than in the absence of 
cane-sugar in the culture. 
There is, further, a laborious research by Weis ( 5 ) into the nature 
of the proteolytic enzymes of malt. The author recognizes that in the 
germination of barley both peptonization and peptolysis take place — or as 
he puts it, there is a ‘ phase pepsique ’ and a * phase trypsique * — whence he 
infers the presence of two distinct proteases which he respectively terms 
peptase and tryptase. The peptic action is apparently rapid, and soon 
comes to an end, whilst the tryptic action is slower and continues until the 
complete decomposition of the products of the peptic stage. The tryptic 
action was found to be only slight, at most, in a neutral liquid ; rapid 
in the presence of a small quantity of added acid (e. g. lactic acid 0-2 °/ o ; 
HC 1 0-04 °/ o ), and much retarded by the addition of alkali. The author 
is of opinion that the effect of acid and alkali upon the activity of 
proteolysis is to be explained, in accordance with the views of Fernbach 
and Hubert (Comptes rendus, t. 131, 1900, p. 393), who regard the primary 
(acid) and secondary (basic) phosphates present in the malt-extract as 
determining the course of proteolysis, the former promoting, the latter 
retarding it. 
The author found both the peptic and the tryptic activity of malt 
to be interfered with by certain antiseptics, such as thymol, chloroform, 
formol, whilst toluol had but a slight effect. In the paper already referred 
to (1) I also have drawn attention to the influence of antiseptics on 
proteolysis in the special case of papain. 
It was further ascertained that the proteases of malt-extract could 
digest various vegetable proteids other than the glutin of wheat ; such as its 
own proteids, proteids of ungerminated barley, of rye, and of oats, legumin, 
vegetable casein ; as also, among animal proteids, the fibrin of ox-blood, 
whilst the action on egg-albumin was slight. 
