192 BUTYRIC ACID FERMENTATION. 



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

 the reaction of the nutrient medium on the progress of butylic fer- 

 mentation was shown by L. GRIMBBRT (I.) in the case of the anae- 

 robic Bacillus 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 substances, normal butyric acid, acetic acid, normal butyl 

 alcohol, and a little iso-butyl alcohol, together with hydrogen and 

 carbon dioxide, being the products of 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 dimi- 

 nishing with the increased acidity thereof, whilst the amount of 

 acetic acid remains unaffected. In harmony with this determina- 

 tion 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 production 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 fer- 

 mentation 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 wide- 

 spread among the bacteria, and is in nowise restricted to the above- 

 named species. Our knowledge 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 BEYERINCK (XIII.) on 

 glucase, the enzyme of maltose. After J. WORTMANN (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. antliracis, B. tetra- 

 genus, B. ramosus, B. Fitzianus, Vibrio cliolerce asiaticce, and 

 others ; this faculty being, on the other hand, lacking in Bacillus 

 pyocyaneus, Micrococcus prodigiosus, &c. According to the re- 

 searches of A. VILLIERS (I.), there occurs among the fission pro- 

 ducts of the action on starch paste of a fission fungus belonging 

 (presumably) to the group of Granulobacteria, a small quantity 

 (0.3 per cent.) of a new carbohydrate, known as cellulosin, which 

 has the formula C 12 H 20 10 + 3H 2 0. The starch-dissolving action 

 of bacteria also probably comes into play in the preparation of the 

 alcoholic beverage known in Central America as chicha. V. MAR- 

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

 four to six hours in water, then boiling for a short time, and after- 



