BACTERIA DECOMPOSING CELLULOSES 193 



The hydrogen organism (Bac. fossicularwn L. et N.) was found to 

 form thin, straight rods (4 to 8 by 0.5/i) in young cultures. With age 

 of culture the cells become longer until they reach a length of 10 to 15^, 

 without increasing in thickness and without forming chains. The cells 

 are often slightly curved, sometimes even spiral-like, especially on 

 precipitated cellulose. At a later stage, one end of the cell swells up 

 gradually and takes the appearance of an oblong and then of a round 

 body. A perfectly round spore develops in this swelling, fills all the 

 space, and has a diameter not exceeding 1.5ju when ripe. After some 

 time, the spore is liberated by the breaking up of the mother cell. Old 

 cultures, in which the decomposition of the paper is well advanced, show 

 only spores with a slight admixture of vegetative forms which are usually 

 in the stage of forming spores. The spore-containing cultures may be 

 stained with a double stain of carbol fuchsin and methylene blue. 

 The organism is never colored blue with iodine and, therefore, lacks the 

 important characteristics of Amylobacter. By repeated transfers on 

 enrichment culture media, a microscopically pure culture of the organ- 

 ism can be obtained, especially if the inoculum is heated for 20 minutes 

 at 90°C. to kill all non-spore forming contaminations. But all repeated 

 attempts to cultivate the organism on solid media failed. This pre- 

 vented a detailed study of its metabolism. 



The methane organism (Bac. methanigenes L. et N.) is quite similar 

 to the hydrogen organism, but is even thinner and more gently con- 

 toured. By several transfers and on heating the inoculum, a culture 

 is obtained which seems microscopically pure. Chains are never formed 

 in a young stage and the cells have a tendency to curve slightly. The 

 spores are smaller than those of the hydrogen form, being 1/x in diameter. 

 Iodine does not give a blue color. Morphologically both organisms may 

 be classified as one species, while, physiologically, they are distinctly 

 different. Attempts to cultivate this organism on solid media and 

 obtain a pure culture also failed. 



Kellerman and associates 6 could not confirm the results of Omeliansky. 

 They even succeeded in isolating from Omeliansky's cultures an aerobic 

 cellulose-decomposing organism. They suggested, therefore, that the 

 cellulose was decomposed by aerobic bacteria in Omeliansky's cultures, 

 while the accompanying anaerobic forms produced gas from the products 

 of decomposition of the cellulose by the former. However, Khouvine 7 



6 Kellerman et al., 1912-1914 (p. 197). 



7 Khouvine, Mme. Y. Digestion de la cellulose par la flore intestinale de 

 l'homme. Cour D'Appel. Paris. 1923. 



