SECTION VII. 



THE FOEMATION OF MUCUS AND ALLIED PHENOMENA 

 OF DECOMPOSITION. 



CHAPTER XXVIII. 



THE IMPORTANCE OF BACTERIA IN THE MANUFACTURE 

 OF SUGAR. 



159. The Zoogrlcea of Leuconostoc Mesenterioides. 



IN the manufacture of saccharose there are occasionally formed certain masses 

 of gelatinous mucus, for the most part merely small colourless or reddish agglo- 

 merations, resembling frog spawn in appearance, but, under special conditions, 

 increasing to masses exceeding a cubic foot in dimensions. Attention was first 

 drawn to them by C. SCHEIBLEK (I.), who, in 1874, subjected them to chemical 

 examination, the result^of which indicated the presence of dextran, a carbohydrate 

 first discovered by him in the plasma of unripe sugar-beet. Scheibler, in fact, 

 regarded this mucus as expressed beet plasma ; but this opinion (which was also 

 shared by E. FELTZ (I.)) was very soon opposed, P. JUBERT (I.) having shown, 

 a few months later, that these gelatinous lumps (known in France as " gomme 

 de sucrerie") continue to develop in sugar solutions. From this he concluded 

 that they are not extravasated beet plasma, but a ferment (a " plant," as he 

 expressly stated), whose reproductive power he succeeded in arresting by means 

 of carbolic acid. The microscopical examination of the mass, however, as first 

 made by F. MENDES and J. BOKSCHTSCHOFF (F.), led at the outset to no 

 satisfactory elucidation. For an accurate knowledge of the true state of the 

 case we are indebted to L. CIENKOWSKI (I.), who, in 1878, proved that the 

 mucous masses in question are composed of bacteria with extraordinarily 

 swollen and gelatinised cell-walls, which cause the individual organisms to 

 adhere together and form the aforesaid large masses, whose superficial con- 

 volutions frequently resemble those of the mesentery. Influenced by Billroth's 

 publication on Coccobacteria septica, and in view of the name Ascococcus 

 Billrothii given by COHN (II.) to a mucus-forming fission fungus, Cienkowski 

 called his microbe Ascococcus mesenteriotdes. The forms of cell which he detected 

 in these mucinous lumps he described as highly diversified : Coccus, Bacillus, 

 Vibrio. 



In the same year VAN TIEGHEM (VII.) published a research on the organism 

 producing these mucinous masses, agreeing with his Russian colleague as to its 

 vegetable nature, though with respect to its position in the botanical system he 

 held other views. According to his observations, the development and repro- 

 duction of this microbe harmonised so well with those of the blue-green uni- 

 cellular algae of the genus Nostoc, that he felt obliged to call it '* white " 

 (chlorophyll-free) Nostoc, and bestowed on it the new generic name of Leuco- 

 nostoc. Contrary to the observations of Cienkowski, who ascribed a copious 

 polymorphism to this fission fungus, Van Tieghem could only discover globular 



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