287 



neutral .sii,e[ar-con tain ing media excites fermentation and thereby 

 proves able to live as a temporary anaërobe. 



The eilief products of tlie fermentation are carbonic acid and 

 alcohol. At the aerobic life a little aceton results, evidently from 

 oxidation ot sugar. 



Anaerobic accumulation is possible in rye paste at 30° C. after 

 short boiling. Aerobic accumulation takes place in dilute malt-wort 

 or broth with 2 '/„ to 5 7„ sugar, after heating at 85° to 90° C. 

 or short boiling with much garden soil and cultivation at 15° C. 

 by which B. rnesentericus is excluded, whose growth minimum is 

 at about 20° C. 



The general distribution of B. polyinyxa in decayed plants and 

 its occurrence in the bark of plajit roots and of the nodules of the 

 Leguminosae reposes on the production ofpectinase, which dissolves 

 the central lamellum of the cellulai- tissues. 



B. polyuiyxa forms much slime from sugar, which must be consi- 

 dered as cell-wall substance. Without carbohydrates or polyalcohols 

 its growth seems impossible, hence it develops but slightly on 

 broth agar. 



The slime may serve as reserve food. 



Laboratory for Microbiology of the Technical 

 High School at Delft. 



