134 



MICRO-ORGANISMS AND FERMENTATION. 



latter, forming principally ethyl alcohol. Bac. ethaceticus. 

 discovered by P. Frankland in sheep manure, produces ethyl 

 alcohol and acetic acid from glycerine, starch, saccharose, 

 lactose, glucose, mannite, and arabinose. Bac. pneumonia. 

 described by Friedlander, is not only a pathogenic organism, 

 but also has the power of decomposing saccharine nutritive 

 solutions, and forming ethyl alcohol and acetic acid. In this 

 connection may be mentioned a lactic acid bacterium found 

 by Kruis and Rayman in sour yeast " goods " which produced 

 ethyl alcohol as a by-product. Duclaux's Amylobacter eihylicus 



has certain charac- 

 CD O O O a 



CO CO* 



teristics in common 

 with A. butylicus, 

 and occurs along 

 with the latter, but 

 produces ethyl alco- 

 hol and acetic acid. 

 Fitz found a 

 species (Bac. butyli- 

 cus) in cow dung 

 which produces con- 

 siderable quantities 

 of butyl alcohol 

 by fermentation of 

 glycerine. Fitz de- 

 scribes it as occur- 

 ring in the form of 



Jig. 26. Bacittug Fitzianm, after H. Buchner. a, b,f, g, Coccus motile rods 5 to 6 U. 

 forms and short rods ; c, e, long rods ; d, spore-hearing rods. . , 



in length and 2 ju. 



wide. He developed it in a solution containing 1 part of potas- 

 sium phosphate, 0-5 of magnesium phosphate, 2 of pepsin, and 100 

 of glycerine in 2,000 of water, to which must be added 20 parts of 

 calcium carbonate, and he found about 8 percent, of butyl alcohol 

 in the fermented liquid. Bac. orthobutylicus, Grimbert, already 

 described, also has the power of producing a considerable quan- 

 tity of butyl alcohol, especially from glucose, when the nutritive 

 liquid has an acid reaction, or when for any other reason the 

 bacteria are in a feeble state. In the same way Perdrix's 

 Bacille amylozyme yields this alcohol on fermentation. 



