Bacteria in Market Milk. 



as for instance the blackleg bacillus, the non-motile butyric acid 

 bacillus (Grasberger and Schattenfroh), and the bacillus of gaseous 

 phlegmons (Frankel). The others are producers of putrefaction 

 and split up the proteids into forms from which volatile fatty acids 

 develop. 



Obligatory fat-splitting bacteria may also, although less fre- 

 quently, be found in milk, as for instance the Bactridium lipolyti- 

 cum (Huss), through the growth of which the milk acquires a rancid 

 taste. The Bacillus fluorescens, Bacillus prodigiosus and others, 

 for instance certain mould fungi, may also produce fat-splitting 

 enzymes. 



Actinomyces form the transition organisms which lead from 

 bacilli to higher fungi. These fungi form long threads with true 

 branchings. Widely distributed on grasses and especially grain, as 

 well as in the soil, they are of course also contained in manure and 

 litter, and may occur in milk and milk products, butter or cheese, 

 and multiply therein. 



As is the case with all milk bacteria, among the actinomyces 

 there may occur forms which under certain conditions such as 

 wound infection, produce diseases (chronic suppurations). 



Some varieties of bacteria classified by Lohnis as lacto-bacilli, 

 as for instance a microbe isolated by Chatter jee from "Dadhi," 

 (Indian sour milk) Streptothrix dadhi and several bacteria which 

 were found in Mazun, Yoghurt and in the Montenegrin "Grusa- 

 vina" and "Kysla varenika," appear from their morphological 

 properties, to belong to the streptothrix (actinomyces). 



Finally it will be advisable to discuss the higher fungi, yeasts 

 and moulds which occur in milk. They cause a slight alcoholic fer- 

 mentation of the milk; not all varieties however attack the milk 

 sugar, although a great number of the most varied fungi and 

 yeast are found in milk, for instance penicilia, mucors, aspergilli. 



By far the most frequent fungus in milk is the Oidium lactis, 

 tinder which name are collected all mycelial forms, whose radiating 

 mycelia carry hyphae, that break up into small, rectangular, cylin- 

 drical members, the so-called oidia, which in proper media again 

 grow out into a mycelium. The growth of the oidium varieties 

 gives the surface of the cream layer a yellowish-white, velvety, fre- 

 quently wrinkled appearance, which later may take up a glassy 

 transparent appearance. 



Oidium lactis causes fermentation in sugar-containing media, 

 and develops carbonic acid and a slight amount of alcohol. A 

 pleasant aroma results from cultures in dextrose but in the split- 

 ting up of saccharose, lactose and maltose, an intensive cheesy 

 odor develops. Besides sugar, proteids if present are split up. 

 Therefore in the zones of growth of the oidium varieties a pepton- 

 ization is manifested in the milk. Lactic acid is also produced and 

 later again disappears. 



Besides the oidia there may also be found the closely related 



