SLIME-FORMING BACTERIA. 145 



gelatine. According to Schardinger, the species is related 

 to Loffler's Bac. lactis pituitosi. A chemical examination of 

 the slime formed by mass cultures from saccharose solutions, 

 containing nutritive salts and calcium carbonate, shows that 

 it chiefly consists of a carbohydrate which by oxidation with 

 nitric acid forms mucic acid, and by boiling with hydrochloric 

 acid produces optically active sugar. As a slime can also 

 be formed by bacteria in the absence of sugar, it should pro- 

 bably be regarded as a product of the swelling of bacterial 

 membrane. 



As an example of one of the species producing a vigorous 

 formation of slime in milk may be mentioned Bac. lactis 

 viscosus, found in water, and described by Adametz. It 

 forms a short, feebly-motile rod with a thick refractive capsule. 

 Its average dimensions (in milk cultures) are 1-5/z long and 

 1-25/x thick. On glycerine-peptone-gelatine it forms whitish 

 non-liquefying colonies with irregular jagged edges, which 

 shows a bright opalescence in reflected light. By inoculation 

 in sterilised milk, the milk becomes viscid like honey in four 

 to six weeks, and may be drawn out into long threads. At 

 the same time the fat globules of the milk disappear. Lactose 

 is only attacked to a very slight extent by this species, whereas 

 casein is greatly modified. Slime is also formed in nutritive 

 liquids free from carbohydrates. It is believed to be a zooglcea 

 formation. 



Other related species have been described by Duclaux, 

 Leichmann, Schmidt-Muhlheim, Loffler (Bac. lact. pituitosi, 

 motionless rods which quickly divide into coccus-like cells, 

 and on gelatine give white colonies with sharp or slightly 

 dented edges), Weigmann (the coccus of " lange Wei " with 

 nitrogenous slime), Emmerling, etc. 



Emmerling has proved that Bac. lactis aerogenes forms a 

 mucilage in lactose solutions possessing the properties of 

 galactan, for by oxidation it may be transformed into mucic 

 acid. 



In beer also slime-forming bacteria occur. Thus H. 

 Schroder (1885) found a Micrococcus in " ropy " Berlin " Weiss- 

 bier/' which was afterwards cultivated in a pure state by P. 

 Lindner, who named it Pediococcus viscosus. The disease 



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