BACTERIA DECOMPOSING CELLULOSES 195 



from that of cellulose decomposition under aerobic conditions. 9 The 

 thermophilic Clostridium thermocellum Vil., Fred and Peterson, described 

 later, is also an anaerobic organism, decomposing cellulose very actively. 

 Aerobic bacteria. The first attempt to study cellulose decomposition 

 under aerobic conditions was made by Van Iterson, 10 who described a 

 non-spore-forming organism, Bacillus ferrugineus, which decomposed 

 cellulose under aerobic conditions, in symbiosis with a yellow micro- 

 coccus, the latter not decomposing any cellulose when alone. 



The following medium was used: 



Tap water 100 cc. K 2 HPO< 0.05 gram 



Filter paper 2 grams CaC0 3 2.0 grams 



NH 4 Cl(orKN0 2 ,KN0 2 , 

 MgNH 4 P0 4 , pep- 

 tone) 0.1 gram 



The medium was placed in Erlenmeyer flasks to a depth of 0.5 to 1 cm., inoculated 

 and incubated at 28° to 35°. Cellulose decomposition was also demonstrated by 

 placing two pieces of filter paper and some powdered ammonium magnesium 

 phosphate in a dish, moistening with a 0.05 per cent solution of K2HPO4 and in- 

 oculating with some soil. Yellowish brown spots were produced on the paper in 

 4 to 5 days; the paper soon became pulpy, and the individual fibers became en- 

 veloped in a "micrococcus mucilage." Pure cultures of the organism could never 

 decompose the paper. 



Merker 11 described two bacteria, Micrococcus cytophagus and M. 

 melanocyclus, neither of which was isolated in pure culture, but which 

 were found to be accompanied by a rod-like organism; they decomposed 

 paper partly immersed in the medium with the formation of transparent 

 yellowish spots. A similar organism was studied by Bojanovsky 12 on 

 silica gel media, but he also failed to separate the coccus-like form from 

 the rod-shaped form. 



The organism (Spirochaeta cytophaga) isolated from the soil by 

 Hutchinson and Clayton 13 was found to develop first as a sinuous 



9 VVaksman and Skinner, 1926 (p. 190). 



10 Van Iterson, C. Die Zersetzung von Cellulose durch aerobe Mikroorganis- 

 men. Centrbl. Bakt. II, 11 : 689-698. 1904. 



11 Merker, E. Parasitische Bakterien auf Blattern von Elodea. Centrbl. 

 Bakt. II, 31: 578. 1912. 



12 Bojanowsky, R. Zweckmiiszige Neuerungen fiir die Herstellung eines 

 Kieselsaure Nahrbodens und einige Beitrage zur Physiologie aerober Zellu- 

 loseloser. Centrbl. Bakt. II, 64: 222-233. 1925. 



13 Hutchinson, H. B., and Clayton, J. On the decomposition of cellulose by 

 an aerobic organism (Spirochaeta cytophaga n. sp.). Jour. Agr. Sci. 9: 143-173. 

 1918. 



