20 



THE BACTERIAL FERMENTATION THEORY OF SUCHSLAND. 



It has long- beeu recognized that the maiu feature of the processes 

 going on in the sweating, or the so-called fermentation, of tobacco con- 

 sists in oxidations. These are accompanied by certain decompositions 

 liberating ammonia, and are the source of the striking development of 

 heat in the fermenting piles. Kow, what is the cause of these power- 

 ful oxidations? i^essler, as well as Schlosing, asserts that it is merely 

 the common oxygen of the air that attacks certain comx^ounds in the 

 cells with great ease, no other cause being required. Schlosing admits 

 bacterial action oul}^ for initiating the elevation of temjierature, but 

 not for the main processes later on. On the other hand, Suchslaud 

 attributes all the oxidations and the development of heat to the action 

 of certain bacteria, which are specific for different kinds of tobacco 

 and which impart to each of them a si^ecific aroma. 



Nessler's and Schlosing's views must assume substances of an unusual 

 affinity for oxygen, if the rather indifferent atmospheric ogygen could 

 exert such a powerful result without the intervention of any activifying 

 ]3rinciple, hence Suchsland's view seemed more probable and soon found 

 many followers. He prepared pure cultures of microbes found upon 

 different kinds of tobacco,^ and by transferring those obtained from 

 Havana tobacco to German tobacco he expected to develop the Havana 

 aroma in the German tobacco, but thus far no new developments have 

 startled tobacco growers. Davalos described mold fungi and microbes 

 occurring upon fermenting tobacco leaves in Havana, but without 

 proving their importance for the fermentation process (see Petuning). 

 Vernhout observed only one kind of bacterium upon fermented tobacco 

 leaves. This developed at 50° C. (122o F.) upon agar plates, and was a 

 thermophile kind of the group of Bacillus subtilis.'^ It develoi)ed also 

 in decoctions of tobacco and Avas capable of decomposing i)roteids with 

 development of ammonia. Yernhout, however, leaves it entirely unde- 

 cided as to w^hether this microbe plays any important i^art in the fer- 

 mentation process. Also Koning ' described several kinds of bacteria 

 from fermenting tobacco leaves which he found to be identical witli 

 those occurring also on the green tobacco leaves. Besides the known 

 bacteria, B. mycoides and B. subUlis, he described five aerobic new 

 kinds, called B. tohacci Nos. I, II, III, lY, and Y, of which B. tohacci 

 III seemed to have most influence on the aroma. These statements 

 may well be doubted, as a direct microscopical investigation of the 

 surface of the fermenting leaves is wanting. 



iBer. d. Dent. Bot. Ges., Vol. IX, 1891. 



"How some authors can assert thajitlie fermentation is caused by a7iac?*o&ic bacteria 

 when it is a known fact that the most important changes going on consist of oxida- 

 tions remains difficult to understand. 



^Zeitschr. fiir Unters. der Nahrungs and Genussmittel, 1898, No. 3. It may also 

 be mentioned that this author claims to have discovered the bacteria causing the 

 mosaic disease of tobacco, while the most careful researches of Bejerinck have 

 proved that bacteria are not the cause of it. 



