148 BUTYRIC ACID FERMENTATION 



so-called " QoargelkSse " (small country ch> -nr soft variety) l.y \'. vo.v 



KLECKI (I.), and examined by him for its fermentative power, also 1 -i 

 hereto. 



The influence of the age of the organisms used as " seed " and the reaction 

 of the nutrient medium on the progress of butylic fermentation was shown by 

 L. GRIMREKT (I.) in the case of the anaerobic /*<<ritfnx orthobutylicus. This was 

 isolated as a pure culture from a fermenting aqueous liquid containing calcium 

 tartrate and leguminous seeds, the said salt being, however, as little affected by 

 the bacillus as is calcium lactate. On the other hand, saccharose, lactose, 

 maltose, invert sugar, glucose, and the like, form favourite nutrient sub.-ta; 

 normal butyric acid, acetic acid, normal butyl alcohol, and a little iso-butyl 

 alcohol, together with hydrogen and carbon dioxide, being the product 

 fermentation. The ratio of these products is found to depend on the reaction 

 of the medium, the yield of butyl alcohol increasing and that of butyric acid 

 diminishing with the increased acidity thereof, whilst the amount of acetic acid 

 remains unaffected. In harmony with this determination is the further fact 

 that, as the age and concurrently the acid content of the fermenting liquid 

 increases, the amount of butyl alcohol produced per unit of time becomes larger. 

 So far as the age of the " seed " (i.e. the germs and organisms transferred in the 

 process of inoculation) is concerned, it is found that, as regards the produc- 

 tion of butyl alcohol, the fermentative power of young cultures is greater than 

 those of more mature age. Sundry experiments in the technical preparation 

 of butyric acid by fermentation were made by L. LEDERER (I.), but these leave 

 much to be desired from a bacteriological point of view. 



The faculty of producing starch-dissolving enzymes is widespread among the 

 bacteria, and is in no wise restricted to the above-named species. Our know- 

 ledge of these amylases or diastases (in the general sense) is, however, still in 

 its infancy. In this connection we may refer to a treatise by BKYKUINTK (XIII.) 

 on glucase, the enzyme of maltose. After J. WORTMANX (I.) had already, in 1882, 

 made a few investigations thereon, but only in bacterial mixtures, CL. FERMI (II.) 

 approached the matter more closely in 1890. According to his observations 

 (made exclusively with pure cultures), diastatic enzymes are excreted by the 

 following species : Bacillus subtilis, B. megatherium, B. anthracis, B. tetragenus, 

 B.ravumu, B. /'/': /V///?f$, I'ibrio cholerce asiaticce, and others; this faculty being, 

 on the other hand, lacking in Bacillus pyocyaneus, Microeoccus prodigio8U8 t iVc. 

 According to the researches of A. YILLIERS (I.) there occurs among the iission 

 products of the action on starch paste of a fission fungus belonging (presumably) 

 to the group of G ranulobacteria, a small quantity (0.3 per cent, of a new carbo- 

 hydrate, known as cellulosin, which has the formula C,,H. < ), + 3H 2 0. The 

 starch-dissolving action of bacteria also probably comes into play in the prepara- 

 tion of the alcoholic beverage known in Central America as chicha. V. MAK- 

 CANO (I.) states that this liquor is prepared by steeping maize for four to MX 

 hours in water, then boiling for a short time, and afterward- leaving the mix- 

 ture to settle, whereupon a bri&k fermentation quickly ensues. More accurate 

 information respecting the fission fungus concerned is still lacking. 



118.- The Fermentation of Cellulose. 



To dissolve and get rid of what has ceased to live is (according to an 

 appropriate remark made by Pasteur) the task of the i'un^i in general, and of 

 the fission fun^i in particular. Without their activity the circulation of the 

 elements of which the organic world is constructed would quickly come to a 

 1-till. and the surface of the earth become in a few yean thickly covered 

 with the dead bodies of animals and plant-. I >' -pectini: the const it uents of the 



