Soluble ferment

The glucosides are compounds, which, under the influence of hydrolytic agents are decomposed into glucose or an allied aldose or ketose, and one or more other bodies, which, in the cases under consideration, form constituents of essential oils. The hydrolytic agents which bring about these changes are soluble ferments, such as diastases, enzymes and similar... 

Further enzymatic conversions (ferment actions) observed in that early period, summarized in Frankland s list of soluble ferments (1885) and by Sumner and Somers (1953) are summarized in Table 1.1. 

The overall research activity on soluble ferments, that is on enzymatic reactions, is scarce in this period nevertheless seen as important (Berthelot, 1857, 1864). Thus in the German Journal fur Praktische Chemie , in the period from 1850 to 1860 no paper dealt with soluble ferments (enzymatic activities) and 8 papers were published on fermentation (Gahrang, with the meaning of microbial activity) in the Bulletin de la Societe Chimique de Paris, one of the most important of the time for fermentation research, there was published about one article per year in the 1860 s dealing with soluble ferments, which signifies enzyme activity, and 3 to 4 dealing with fermentation (Table 1.2). It was only in the 1880 s that research and publication activities rose significantly. 

A pronounced increase in papers on soluble ferments (Table 1.2) indicated the growing interest, and several key findings initiated the enzymology of the 20th century. 

Table 1.2 Numbers of articles on soluble ferments in the mid-18th century.

Index Entries Ethanol germ fiber oil distiller s dried grains and solubles fermentation. 

By the end of the small intestine, deposition is almost complete and there is no need for intestinal secretions to aid assimilation. The principal role of the colon is to resorb water and reclaim sodium however, complex carbohydrate components of vegetable origin have nutritional value but are relatively resistant to attack from intestinal secretion. In the caecum, a complex bacterial environment digests the soluble, fermentable carbohydrates to yield short-chain fatty acids, which are assimilated into the systemic circulation by the colon, together with vitamin K released from the plant material. 

The term ases is suggested in order to designate the totality of the soluble ferments (diastases or enzymes). The names of all the ases must have the suffix -ase. 

Pasteur became increasingly convinced that real fermentation always required the presence of living microorganisms and that chemical reactions catalyzed by soluble ferments such as the splitting of protein by pepsin or carbohydrate by diastase were in reality entirely different phenomena. He now introduced his famous concept of fermentation proprement dite (approximately, fermentation in the proper sense of the word ), which he defined in such a way that he excluded all fermentation processes that did not include microorganisms. Armed with this marvellous example of a circular argument he now attacked his opponents, the chemists. 

At the time of Pasteur s quarrel with Berthelot over the publication of Bernard s posthumous manuscript, the number of the controversial soluble ferments approached 20, and in 1878 the German biochemist Willy Kuhne (1837-1900) suggested that such ferments should be called enzymes. At the same time, he carefully avoided taking sides in the conflict between vitalists and chemists, the new term was just a question of convenience. The name enzyme was not an immediate success. The leading German biochemist Felix Hoppe-Seyler (1825— 1895), for instance, said scornfully The new word enzyme could be added to the large number of new names that Kuhne has proposed for totally unknown substances. Nevertheless, with time the word enzyme would completely replace ferment and is now the only term used. 

The pharmacological action of anhaline (hordenine) was first described by Heffter (49). In frogs it causes paralysis of the central nervous system without previous excitation. Camus (130-133) reported that the compound is slightly antiseptic it also has an inhibitory effect on some soluble ferments. In mammals it shows relatively low toxicity. Small doses have no effect on the circulation of the blood larger ones raise the blood pressure and accelerate the pulse in very large doses hordenine causes death by arrest of respiration. 

This disproportion between cause and effect, as well as this immutability, which is found with all these active substances, justifies their being gathered into a well-characterized group. To this class of bodies has been given various names, such as soluble ferments, diastases, or better still, enzymes. A detailed study shows that all these substances offer a close analogy to the so-called catalysts of inorganic chemistry. It therefore appears to us that the term biochemical catalysis would be a most suitable... 

Soluble ferment Substrate Products Enzyme present in soluble ferment... 

The same decade saw the development of a modem concept of enzyme action. Fischer published his studies of the hydrolyses of the a- and )S-glycosides of d- and L-glucose in 1894 (Boyde, 1980 Teich and Needham, 1992). The active agents which he used to catalyse these reactions were the soluble ferments separated from S. cerevisiae and other microoiganisms, the so-called enzymes , as he described them, using the term which Kiihne had introduced in 1878 (Boyde, 1980). Some of these preparations catalysed a range of hydrolyses which do, in fact, reflect the action of several enzymes (Boyde, 1980) nevertheless, their specifications were sufiiciently clear cut to allow him to propose... 

In the past, plants containing HORD have been used as a diuretic and also for the treatment of diarrhea and dysentery as folk remedies. HORD was shown to be a weak antiseptic and inhibit some soluble ferments [45]. 

We will briefly consider now the step of cake washing. This step is undertaken to recover the solutes left in the solution trapped in the cake mass. As the wash liquid displaces this trapped solution, the latter goes through the filter medium and is recovered in the filtrate inside the drum. Therefore, washing enhances the recovery of soluble fermentation products left in the liquid in the cake mass in the case of a fermentation broth. Since the wash liquid is suspension-free as well as solute-free, the cake filtration characteristics are unlikely to be altered. Hence, the filtration rate during washing should correspond to the filtration rate existing at the location where the drum came out of the suspension ... 

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