2 72 BACTERIA IN THE MANUFACTURE OF SUGAR. 



a 



of the gelatinous mass, which from its nature was very likely to 

 have become infected by any number of fission fungi during its 

 removal from the sugar-works at Orlovetz to the laboratory of 

 Charkow. 



The discoveries made by Liesenberg and Zopf that this microbe, 

 when grown in or upon nutrient media free from cane- or grape- 

 sugar, does not develop a mucinous envelope, but grows in chains, 



and consequently assumes 

 the streptococcus form 

 (Fig. 55), are entirely 

 new. Such nutrient 

 media are : Solid potato 

 slices, peptonised meat- 

 broth gelatin, milk gela- 

 tin, maltose gelatin, on 

 all of which it develops 

 merely a thin pellicle 

 without any formation 

 of mucus ; Liquid milk 

 and bouillon, in which 

 merely a fine sediment 

 of cells is deposited. If, 

 however, a small portion 

 of such a culture of non- 

 mucinous cells be trans- 

 ferred to a medium 

 containing saccharose or 

 dextrose, the formation 

 of mucus quickly ensues. 

 Under these conditions 

 there then develop (on 

 slices of carrot, in par- 

 ticular) large zoogloea, at 



a, b. chains and bands of the non-capsuled variety, fl j. ,]... ]:i. p nartilflo-n 



potato culture ; c, e. cells with gelatinous cap- nrst ai T> llKe cartilage, 



sule in various stages of development. In done but afterwards becoming 

 pair of cells is viewed in the direction of the line ,. , , .MM. 



joining their centres, and hence appears as a SOtter and resembling 



mesentery in appearance. 

 Under the microscope 

 it appears as shown in 

 Fig. 55. The cells, always 

 globular, are invariably arranged in pairs, i.e. as diplococci. The 

 greatly swollen mucinous capsules of the individual cells gradually 

 coalesce and form agglomerations of constantly increasing size, 

 in which the diplococci are enclosed. Locomotion could not be 

 detected in any case. 



Not only was Cienkowski's work corrected by the researches 

 of Liesenberg and Zopf, but the same fate also befell some of the 

 statements made by Van Tieghem. The latter thought he had 



FIG. 55. Leuconostoc mesenterioides. 



app< 



simple' cell, not as a diplococcus. The shading 

 in c-e merely indicates the configuration of the 

 agglomerations, and not a stratification of the 

 about 1200. (After Liesenberg 



