STUDIES ON THE DECOMPOSITION OF CELLULOSE 



IN SOILS' 



By 



I. G. McBeth 



Introduction 

 The discovery and comprehension of the biological and chemical 

 forces relating to the decomposition of the carbohydrate materials in soils 

 is unquestionably necessary to the solution of many problems in soil fer- 

 tility and crop production. A large percentage of the carbon content of 

 the plant residue is found as a constituent of the celluloses. These com- 

 pounds, because of their refractory nature, must first be attacked by a 

 special group of organisms. An accurate knowledge of the cultural and 

 biochemical characteristics of tlie organisms involved in the transforma- 

 tion of cellulose into less refractory compounds is, therefore, obviously of 

 the greatest importance. 



Extensive investigations during the last few years have shown that the 

 decomposition of cellulose is by no means limited to the bacteria of soils. 

 The filamentous fungi possessing this power are very numerous and 

 many species are exceedingly active agents in the destruction of cellulose. 

 In the humid soils of the East the filamentous fungi are perhaps of 

 greater importance than bacteria in the destruction of cellulose, while in 

 the semi-arid soils of the West tlie reverse is apparently true. Several 

 species of Actinomyces are also known to have tlie power of dissolving 

 cellulose and because of their general distribution, these organisms are 

 undoubtedly a factor in tlie destruction of cellulose in soils. This paper 

 deals, for the most part, with investigations of cellulose-dissolving bac- 

 teria. 



Culture Media 

 Methods for the preparation of cellulose agar and other suitable cul- 

 ture media for the study of cellulose-dissolving bacteria have been dis- 

 cussed, at some length, in earlier publications by Kellerman and McBeth 

 (29), McBeth and Scales (43), Lohnis and Lochhead (40), Kellerman, 



^ Paper No. 16, Citrus Experiment Station, College of Agriculture, University of California, 

 Riverside, California. 



Received for publication March 30, 1916. 



A bibliography of the literature relating to cellulose destruction is included and reference is 

 made by numbers to "literature cited" (p. 481 ). 



(437) 

 (31) 





3505^^1 



