Ammoniacal fermentation

This is formed of the nitrogenous substances (casein, albumin) and fats contained in milk, separated by coagulation (by rennet or by acidification). As a result of special fermentations which occur during the maturation of the cheese, these give rise to soluble albuminoid substances (albumoses, peptones, etc.), amino-adds (phenylaminopropionic add, tyrosine, leucine, etc.), ammoniacal products, fatty adds (lactic, propionic, caproie), etc. Cheese also contains water and mineral salts, including added sodium chloride. 

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. 

Sablayrolles, J.M., Dubois, C., Manginot, C., Roustan, J.L., Barre, P. (1996). Efectiveness of combined ammoniacal nitrogen and oxygen additions for completion of sluggish and stuck fermentation. J. Fermen. Bioeng., 82, 377-3S1... 

The ammoniacal fermentation of the urea proceeds until about 13 per cent of ammoniacal carbonate is formed in solution, when it ceases. Nitrogen in thi form of ammonium carbonate is directly assimilable as a plant food, being buil up again into, vegetable proteins, which form the food of animals. 

Litmus is procured by fermentation of ammoniacal extracts of various lichens, especially of the species Rocella and Lecanore. The commercial product is a mixture of various substances, many of which are totally devoid of indicator properties. From such a preparation have been isolated azolitmin, erythrolitmin, erythro-lein, and spaniolitmin. Only the first of these compounds has any practical value. P. Scheitz claims that even azolitmin is a mixture. 

Ammoniacal fermentation, or alkalinization and decomposition of urine, is responsible for the foul odor of urine (Kraemer, 1964). The results of one study (Kraemer, 1964) found that a single dose of 16 oz of cranberry juice lowered the urine pH of six men with chronic urinary tract disorders, and decreased ammoniacal odor and turbidity. The urine pH of five of six men free of urinary tract infections was also lowered with this dose. In another study (DuGan and Cardaciotto, 1966), hospital personnel noted a decrease in urine odor in the geriatric wards of a nursing home, but a change in urine pH or change in ammonia levels in the air could not be detected. Other subiective... 

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. 

This disintegration of the albuminoid substance, which converts almost the whole of the organic nitrogen into ammonia, results from the combined action of numerous micro-organisms, of different species and nature. The products elaborated by one class of bacteria often serve as the point of attack for another. Thus the volatile acids and oxyacids furni.shed in the course of ammoniacal fermentation constitute a nutritive rruitcrial for the ferments of cellulose, bacteria abundantly represented in the soil Calcium acetate, as well as its homologues, react under these conditions in the following manner ... 

Intensity of Ammoniacal Fermentation According TO the Nitrogen Content. 

From 1906 to 1908, acclimation resulted in an increase of from 5 to 16 g per liter in the nitrogen content of the mash treated. At the same time an increase was observed in the virulence of the bacteria This gave originally, in 24 hours, 0.15 g of ammoniacal nitrogen, and it ended by giving 1.45 g. It also became much more reastant to heat its optimum temperature, which was 42°, was finally raised to 55°. However, in this condition, the ferment does not yet show the noaximum activity The yield is not theoretical, and to obtain a better result, recourse must be had to a strong aeration and to additions of culture earth, as well as salts of aluminium. 

One of the first to fractionate the nitrogen compounds of wine was Barbera (1933c). He reported only three—ammoniacal, amide and amine, and total nitrogen. His data indicate the possible amount of amino acids in wine and also how much is removed by fermentation. The first extensive fractionation of the nitrogenous material in wines was that of Muth and Malsch (1934). The following indicates some of their results (as milligrams per liter) ... 

Alkali from all plants is the same. The mineral alkali (soda) is really contained in some plants, from which it is obtained on combustion. Although the volatile alkali (ammonia) may be obtained from some plants by dry distillation or from mushrooms, it is possible that it may have come from animal debris, and its source must (apart from volcanic sal ammoniac) be sought in the animal kingdom, in which it exists tout forme , or is formed by putrefaction, which (in spite of Boerhaave s distinction) is a species of fermentation, an internal spontaneous movement giving different products. Volatile alkali is rich in phlogiston and precipitates metals it liberates inflammable air from zinc. ... 

Adding excessive amounts of nitrogen may also result in the presence of non-assimilated residual nitrogen at the end of fermentation. Although there are no specific data on this issue, residual nitrogen may have a negative impact on a wine s microbiological stability. An excess of ammoniacal... 

The addition of ammoniacal nitrogen often promotes the fermentation of these musts, depleted by the development of Botrytis cinerea. An addition... 

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. 

History.—The ammoniacal fermentation of urine, which takes place spontaneously when urine is exposed for some days to the air, depends on the conversion of urea into ammonium carbonate by the urease-forming micro-organisms that aboimd in the environment. 

Urine that has become strongly alkaline owing to ammoniacal fermentation must be acidified slightly with acetic acid before the presence of protein can be detected by the heat-coagulation test. 

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