FERMENTATION WITH SPECIAL REFERENCE TO THE SUGAR HOUSE 



Mucoraceae. The Mucoraceae or pin moulds are of frequent occurrence as 

 objectionable organisms in distilleries; some of them can produce limited 

 quantities of alcohol. Mucor oryzae, which is perhaps the same as Rhizopus 

 oryzae, was isolated by Went and Geerligs 9 from Raggi; this fungus can 

 saccharify starch, but does not produce alcohol. Mucor Rouxii, isolated from 

 Chinese yeast, has enjoyed some notoriety as an economic alcohol producer, 

 but does not now seem to be a likely rival to the Saccharomyces. 



Fungi imperfecti. By this term is meant those fungi the classification of 

 which is uncertain; included here are the Torulae (by which term is now meant 

 a non-sporing yeast-like organism fermenting sugar) and the Mycordermae or 

 true film fungi connected with the oxidation of alcohol to acetic acid. Momlia 

 iavamca was isolated by Went and Geerligs 9 from Eaggi ; it produces up to 

 5 per cent, of alcohol to which it gives an unpleasant taste. An allied organism, 

 isolated by Peck and Deerr 5 from a Natal distillery, was remarkable for its high 

 production of acetic and butyric ethers, as much as 7558 parts ethers as acetic 

 ether being produced per 100,000 of alcohol. 



Bacteria. Numerous bacteria are connected with the sugar fermenta- 

 tion industries ; a systematic account of such as have been studied herewith is 

 quite without the limits of the present work. It may be at once stated that 

 generally bacteria are a prolific source of disease and loss in distilleries, 

 especially in rum manufacture, although as shown later in grain distilleries at 

 one stage their presence is essential; to their presence may be attributed 

 imperfect attenuations and low returns. Some particular types of bacterial 

 activity of greater interest are briefly mentioned below, and it must be 

 remembered that in all cases the types of fermentation referred to in a heading 

 may be brought about by any one of a number of dibtinct organisms. 



Lactic Acid Fermentation. The importance of the bacteria 

 which produce lactic acid in green malt in cereal distilleries is shown in a 

 subsequent section ; they occur chiefly in sour milk and in green malt ; through, 

 their agency the production of lactic acid from beer wort has been proposed,, 

 and its production from molasses does not seem prima facie impossible; certain* 

 species have been noted as causing disease in beer. 



Acetic Acid Fermentation. This fermentation is economically 

 of importance in the production of vinegar from alcohol ; it may take place 

 under the influence of certain well defined bacteria or under that of an imperfect 

 fungus, referred to as Mycoderma vini ; generally it is essentially a process 

 of oxidation, but Watts and Tempany have shown that the spontaneous souring 

 of cane juice proceeds anaerobically, the sugar forming the source of oxygen. 

 Acetic acid has been observed by Grieg Smith 11 in soured sugar, and sugar 

 or juices left in crevices about a sugar factory undergo this fermentation 

 and are responsible for the sour smell often observed ; wash kept after the 

 alcoholic fermentation is complete also undergoes acetic fermentation, and the 



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