Synbiotics
One researcher reports treating grain, sorghum or barley with the enzyme "gumase" while another reports the same with the enzyme "beta-glucanase" When methodologies are examined, itis discovered that both of these preparations are the same product. Unfortunately, this apparent contradiction in terms happens often. Enzymes have been named byseveral methodsand this fact has been known to cause confusion intheir classification. For example, common or "trivial" names of enzymes, generally contain a prefix representing the name of the substance or substrate upon which they act or affect, followed by the suffix"ase". The "ase" simply denotes or identifies that the substance is an enzyme. Examples of this system of nomenclature includes the enzyme that catalyzes the conversion of proteins into their component amino acids, the name of this enzyme is "protease" or "proteinase".
Another example is the enzyme that accelerates the break down of the two components of starch into sugars. The components of starch are known as "amylose" and "amylo-pectin", thus, the enzyme helping to break them down is called "amylase". Confusion may exist, however, when older names of enzymes are used.Included in these older terms are ficin, pepsin, bromelin and trypsin, which are older trivialnames of individual types of protease preparations, the enzymes that accelerate digestion of proteins. There are also many sub- classes of enzymes. Amylases are a prime example; subclasses of amylase include: alpha-amylase, beta-amylase, and gluco-amylase, to name a few. All these enzymes do is accelerate the digestion of starch and are broadly classified as amylases, but their actions are all slightly different in nature.
To help sort this out, the International Union of Biochemistry in 1961 proposed a system for enzymes' classification and naming which is finding acceptance mainly in this discussion. One example of this system, however, is the term:"alpha 1, 4-glucan glucanohydrolase" which is a name for alpha-amylase.
All these systems of nomenclature may become confusing to someone who has use for only a few types of enzymes or uses them for industrial or agricultural purposes. Therefore, the use of the more widely known terms such as "amylase" and "protease" are more or less universally in these fields. It should be remembered, however, that there are many types of enzymes that fit into these broad categories that may be more or less suitable for specific agriculturally related application. The final selection fora specific application should be made only after consulting a knowledgeable individual well versed inthe technical aspects ofthe particularenzyme requirements and applicable characteristics.
Enzymeshave been isolated from every type of living organism. Many of these biological catalysts are significant only from an academic or medical standpoint, but some of the available enzyme from this vast repertoire have been utilized for agricultural and industrial purposes for years. The table below lists several of the industrially on sequential enzymes andtheir sources in nature. It is significant to note that animals plants and microorganisms all yieldindustriallyimportant enzymes. Some enzymes of animal or plant origin have been used in agricultural applications; however, those enzymes most broadly used are of microbial origin.
Source of Enzyme
PLANT
- Malted grains or tubers Amylase
- Pineapple Bromelin (Protease)
- Fig Tree Ficin (Protease)
- Papaya Papain (Protease)
ANIMAL
- Liver Catalase (Peroxide Breakdown)
- Calf Stomach Rennet/Chymosin (Milk Clotting)
- Hog Stomach Pepsin (Protease)
- Hog Pancreas Pancreatic Enzymes (Several)
- Digestive Tract Trypain (Protease)
MICROBIAL
Fungi (Molds and Yeast) amylase, beta glucanase, hemicellulase, protease, cellulase, pectinase, lipase, (many types of each), lactase
BACTERIA
Amylase, protease, isomerase, lactase (many types of each), rennet, oxidase, catalase, beta-glucanase, hemicellulase.
*While enzymes for diagnostic or medical purposes are most important for the benefit of thousands of patients yearly, their discussion is beyond the scope of this article.
One encounters many digestive or hydrolyzing enzymes in the digestive tract of human andother animals. These biological catalysts are necessary for the full utilization of foods ingested. Microorganisms, many being as small as 1/10,000th of an inch in length, are much too minute to have complicated digestivesystems as animals do. Therefore, these microbes must predigest their potential foods outside of their cell boundaries so that they can absorb the very small nutrient compounds of predigested foods.
In order to predigest the potential food sources outside their cell boundaries, many microbes excrete enzymes out through their enveloping membrane with its supportive cell wall and into the surrounding environment. Since these"extra-cellular enzymes" must function in the environment outside the protection of the cell's wall and membrane, they must be reasonablystable andhave relatively high resistance to chemicals and must function over a relatively broad temperature range. To realize the effects of the enzymes they produce, microorganisms also must produce relatively large quantities of these catalysts. All of these factors contribute to the industrial significance and durability of extra-cellular microbial enzymes.
It should be noted that most of the agriculturally and industrial important enzymes, are those that catalyze the digestion or "hydrolysis"of certain large organic molecules like starch, cellulose, and protein.The enzymes actually attack these complex molecules, accelerating their digestion and yielding simpler substances. Since this process of digestion is referred to as hydrolysis, the enzymes that catalyze the process are considered to be "hydrolyzing enzymes" or "hydrolases".
The hydrolyzing enzymes include:
(1) Amylases, which catalyze the digestion of starch into small segments of multiple sugars and into individual soluble sugars.
(2) Proteases, (or proteinase), which split up proteins into their component amino acid building blocks.
(3) Lipase, which split up animal and vegetable fats and oils into their component part: glycerol and fatty acids.
(4) Cellulase (of various types) which breaks down the complex molecule of cellulose into more digestible components of single and multiple sugars.
(5) Beta-glucanase, (or gumase) which digest one type of vegetable gum into sugars and / or dextrins.
(6) Pectinase which digests pectin and similar carbohydrates of plant origin.
Microbial enzymes are manufactured by growing the microbial cells under specialized conditions so that these cells produce their maximal amount of active enzymes. It is important to control environmental conditions during productions so that a high percentage of these active catalysts are preserved intact.After the microbial cells have finished growing and producing their enzymes, they may be inactivated and harvested along with the enzymes, or the material may be process in various ways in order to reach several stages of purificatory of the enzymes. Where other concerns, like solubility or spray ability of the final enzyme containing product enter, the use of asemi-purified soluble or extracted, soluble products are desirable.
Depending upon the products' degree of processing and selectivity of enzymes contained, the products are listed as follows in the ingredients statements:
Dried _________________ Fermentation Extract
Dried _________________ Fermentation Soluble
Dried _________________ Fermentation Produc
tLiquid ________________ Fermentation Product
The scientific name of the microorganism used to produce the enzymatic ingredient would be substituted for the blank provided. The AFFCO Official Publication specifies that enzyme activity will be guaranteed for those products that represent themselves as having enzyme activity.
Wastes processing levels usually dictate some variation in physical conditions under which the enzyme products must function.In order to utilize enzymes to their optimal potential in catalytic ability, we must be familiar with the basic principles that can affect the activity and stability of these enzymes. Enzymes, being biological compounds and being comprised of a high percentage of protein, are subject to many environmental effects. Although the following principles hold true for most biological enzymes produced for commercial agricultural use:
The pH of the environment has a profound affect on enzyme activity and stability. Activity optimal for pH's of various enzymes vary; however, the optimal pH's for the biological catalysts produced by most commercial strains of microorganisms lies between pH 4.0 and 7.5. This range is from moderately acidic to mildly alkaline in nature. These are thepH levels normally encountered.Another major affect of enzyme activity and stability is temperature. Since enzymes are biochemical catalysts, made up at least partially of protein, they are sensitive in varying degrees to heat. Raising temperatures oftheenvironmentgenerally multiplies the degree of activity by the enzyme.Once an optimum temperature has been reached, however, even higher temperatures cause rapid degradation of the enzyme withconcurrent and irreversibleloss inactivity. Optimal temperatures generallyrange from 98 °F to 140 °F (37°C to 60°C)for most hydrolytic enzymes. High temperatures(over 150°F, 66°C)generally have detrimental effects on the enzymes. However, there is broad variation in resistance and sensitivity to heat among the enzymes' types. Bacterial enzymes such as those fromBacillus subtilis are less sensitive to heat than are the fungal enzymes of A. oryzae. Some amylase preparations prepared by the fermentation of Bacillus species can withstand even boiling for short periods and have optimal activities in the 158°F - 176°F (70°C - 80°C) range. Our laboratory has determined that approximately 85% of the activity from Bacillus subtilis/licheniformis alpha-amylase survives high heat. A. oryzae amylases, however, showed a greater than 90% loss activity in high heat. When the enzyme-bearing, dried fermentation products ofthese two microorganisms are kept dry, they are much more resistant to environmental temperature stress than ifthey are moistened. In fact, very few stability problems are encountered with most enzymes in typical situations.
Basic Knowledge of Enzymes Applied
Making use of general knowledge about enzymes including how they act, under what conditions they perform, and how to preserve their activity is important in applying the technology of enzymes to organic waste digestion.
Helpful References on Enzymes:
Aunstrup, K. 1979. In Enzyme Technology, L.B. Wingard, Jr., E.
Katchalek-Katzir,
L. Goldstein (ed). Academic Press, Inc., New York.
Boyer, P.D. (ed). 1971. The enzymes, 3rd, ed. Vol. 5. Academic Press, Inc., New York.
Fogarty, W. M. 1974. Enzyme technology - projects and developments. In Projects and prospects in industrial fermentation: proceedings of meeting held in Holly Royde. A. J. Powell and J. D. Bu'Lock (ed). U. of Manchester. Manchester, England.
Godfrey, T. and J. Reichelt (eds). 1983. Industrial enzymology: the application ofenzymes in industry. Nature Press. New York.Kulp, K. 1975. Carbohydrases and other enzymes.