332 CELLULOSE-DECOMPOSING ORGANISMS 



with iodin, and consequently are different from the amylobacter 

 of Trecul. No growth occurs usually in the ordinary cultural 

 media, though Omelianski has observed on some occasions very 

 minute translucent colonies on potatoes. 



This investigator carried out quantitative determinations of the 

 substances yielded by the organism. It was done in flasks con- 

 taining 300 c.c. of a mineral salt solution containing calcium car- 

 bonate and Swedish filter paper. The flasks were inoculated 

 with the organism and incubated for thirteen months. On analysis 

 the following results were obtained: 



Resulting products. 



Cellulose at beginning of process 3 . 4743 Fatty acids 2 . 2402 



Cellulose at end of period . . 0.1272 Carbon dioxid 0.9722 



Decomposed 3.3471 Hydrogen 0.0138 



Chief among the fatty acids yielded were acetic, butyric, and 

 valeric acid. Besides these there were traces of the higher acids 

 found. 



The methane fermentation, according to Omelianski, takes 

 place if a flask containing filter paper, lime and a mineral neutral 

 solution be inoculated with mud or fresh horse manure and kept 

 under anaerobic conditions at a temperature of from 35 to 37 C. 

 After a short time a careful examination of the filter paper revealed 

 numerous bacilli. By successive subculturing, while the methane 

 fermentation was at its height, the hydrogen ferment was soon 

 eliminated. The methane organism is rod-shaped, slightly more 

 bent than the hydrogen ferment. It never develops in chains, 

 but in old cultures assumes the typical drumstick form with a spore 

 in the end. The organism is 0.4 /* in width and 5 /* in length. It 

 is not stained blue by iodine and hence is different from the amylo- 

 bacter of Trecul. From this it may be seen that both the vegetative 

 cell and spore are slightly smaller than the hydrogen ferment. 

 Though morphologically very similar, physiologically they are 

 very different, since one yielded hydrogen and the other methane. 

 This is shown by the quantitative studies of Omelianski. They 

 were conducted in 500 c.c. flasks containing 2.0685 gms. of Swedish 

 filter paper, 4.9482 gms. of calcium carbonate, and a 0.1 per cent, 

 solution of ammonium sulphate. They were inoculated with 0.013 

 gm. of filter paper from an old culture. Over one month elapsed 

 before fermentation became perceptible and even then it was very 

 slow as is shown by the fact that the gaseous material evolved 

 never exceeded 1.1 c.c. in twenty-four hours, and at the end of 

 four and a half months had dropped to 0.01 c.c. for twenty-four 

 hours. The resulting gas was mainly carbon dioxid and methane, 

 0.7146 gm. of the carbon dioxid and 0.1372 gm. of the methane. 

 In the flask there remained only a small amount of cellulose but 



