THE FERMENTATION OF CELLULOSE 149 



latter a few words will now be devoted to the fate of the Cellulose, of which the 

 greater part of the cell walls of plants is composed. Here the question arises as 

 to how the carbon in this substance is set free again, and the gradual, and finally 

 complete, accumulation of this element in a useless form prevented. In this 

 case once more assistance is afforded by bacteria, which split up the cellulose and 

 remove it out of the way. 



E. MITSCHEELICH (I.) was the first, in 1850, to comment on the natural 

 decomposition of cellulose, by expressing his opinion that it was attributable to 

 the fermentative activity of vibrios. The probability of his view was increased 

 by Popoff's (I.) discovery in 1875, that this decomposition process can be 

 moderated or completely arrested by the addition of substances poisonous to 

 bacteria. A closer investigation of the organisms in question was undertaken 

 two years later by VAN TIEGHEM (IV.), who gave them the name of Bacillus 

 amylobacter, and (V.), from microscopical examination only, declared them 

 identical with Pasteur's vibrion butyrique. 



It would be useless at the present time to argue on this assumption, since 

 both observers worked with what were probably complex mixtures of several 

 species, certainly not with pure cultures. On the other hand, Van Tieghem's 

 further demonstration that petrified cells of (morphologically) similar fission 

 fungi are also to be found in the fossil coniferse of the Carboniferous period is 

 worthy of mention. 



A. H. 0. VAN SENUS (I.), in 1890, endeavoured to obtain a pure culture 

 of the organism giving rise to cellulose fermentation. According to him, a 

 symbiosis of two species is here in question, the one of them which he named 

 Bacillus amylobacter occurring in the form of rods 0.8-1 /z broad and 210 p in 

 length, which, under special conditions, are stained blue by iodine. When air is 

 admitted they form endospores, which then germinate only when air is excluded. 

 The second of these symbiotic species is of much smaller dimensions, and is 

 by itself, like the B. amylobacter, incapable of fermenting cellulose. For this 

 purpose the conjoint effect of both species is necessary, an enzyme being then 

 excreted which dissolves the cellulose. Van Senus isolated this enzyme, and 

 demonstrated its solvent power on cellulose by applying the alkaline solution 

 (containing chloroform in order to suppress bacterial growth) to the cell walls of 

 slices of beans. 



V. OMELIANSKY (I.), in 1895, obtained very different results. He inoculated 

 a mineral nutrient solution (containing potassium phosphate, magnesium sulphate, 

 ammonium sulphate, and chalk), in which strips of Swedish filter-paper were 

 held in suspension, with a small quantity of mud from the Neva, and then kept 

 the whole at 3o-35 C., air being excluded. Fermentation rapidly set in, the 

 strips of paper gradually becoming thinner, and finally disappearing altogether. 

 By repeated transferences of small portions of the fermenting liquid to fresh 

 sterile media the ferment was purified, and finally brought into a state of pure 

 culture by anaerobic cultivation on discs of boiled potato. Omeliansky describes 

 the organism as an unusually slender bacillus, measuring only 0.2 to 0.3 /* in 

 breadth for a length of 6-7 n, and forming terminal globular endospores i /i in 

 diameter, whereby the pole at which the spore occurs is swollen up. 



As in many other directions, here also, in the case of the fermentation of 

 cellulose, the extension of our knowledge is dependent on the elucidation, still 

 to be made by chemists, of the composition of the substances subjected to 

 investigation for the products they yield on fermentation. At the present time 

 the essential requirement that the ferment shall be used in a state of pure 

 culture is almost fulfilled, but so far as the purity of the cellulose to be decom- 

 posed is concerned matters are by no means on a satisfactory footing. ERNST 

 SCHULZE (I.), in 1895, in a treatise setting forth the present state of our know- 



