Fermentation, alcoholic ammoniacal

Mauricio, J. C., Ortega, J. M., and Salmon, J. M. (1995). Sugar uptake by three strains of Saccharomyces cerevisiae during alcoholic fermentation at different initial ammoniacal nitrogen concentrations. Acta Horticult. 388,197-202. 

The catalyst intervening in the decoir sition of urea was discovered in 1874 by Musculus, who found that ammoniacal urine, filtered and evaporated in a vacuum, is capable of causing the fermentation of fresh urea, giving a thick and viscous product similar to that obtained by precipitating decomposed urine with alcohol. Musculus thus established that the production of ammonia is not due exclusively to the ferment, but claims that it results from the action of a special substance of enzymic nature secreted in the bladder. Thus, while finding the presence of the enzyme, Musculus did not comprehend the relation which exists between the bacterium and the active substance. It was Miquel who definitely demonstrated that the enzyme acting on urea is indeed secreted by a micro-organism. This special catalyst was first described under the name of urase, then under that of urease. 

The History of Enzyme Chemistry.— Four spontaneous natural changes have been known to man ever since he first acquired the power of rational observation. They are (i.) the alcoholic fermentation of sugars (ii.) the lactic fermentation, or souring, of milk (iii.) the acetic fermentation of wine and (iv.) the ammoniacal fermentation of urine. Each is due to the growth of a microscopic organism and its attack on a particular substance or svhstrate. The mechanism of these natural fermentations remained completely obscure until the beginning of the last century. 

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