Cellulase is an enzyme which breaks down cellulose to beta-glucose. It is produced mainly by symbiotic bacteria in the ruminating chambers of herbivores. At least two steps in cellulose degradation by microorganisms begin with the preparatory prehydrolytic first step involving an enzyme (C1) which swells and/or hydrates anhydroglucose chains. The second step uses hydrolytic enzymes (Cx) and beta glucosidase (cellobiase). Trichoderma reesei has an extensively studied cellulase enzyme complex. This complex converts crystalline, amorphous, and chemically derived celluloses quantitatively to glucose. Cellulase derived from Trichoderma longbrachiatum is comprised of an enzyme complex consisting of cellulase, a glucosidase, cellobiohydrolase and a glucanase. This complex converts cellulose to beta-dextrins and ultimately to D-glucose. Cellulase is used as a digestive aid, particularly in animals, and for the management of flatulence.

Cellulose is an indigestible plant polysaccharide. It is the principal constituent of the cell wall of plants. Cellulase has cellulolytic activity, meaning that it hydrolyzes cellulose. Cellulase hydrolyzes the beta-D-1, 4-glycosidic bonds of cellulose. Cellulase enzymes show activity during the ripening of some fruits, where their effects on cell walls results in softening of the fruit. The vital characteristics of this cellulase complex are 1) the system is multienzymatic; 2) at least three enzyme components are both physically and chemically distinct; and 3) all three components play essential roles in the hydrolysis of cellulose to glucose. The assay for cellulase activity uses a method which determines the effect of cellulase on microcrystalline cellulose with respect to glucose formation. Released glucose is determined in a hexokinase/glucose-6-phosphate dehydrogenase system at 340 nm.

Cellulase is an enzyme that breaks down cellulose, the carbohydrate that is the main part of the cell walls of plants. Cellulose is nondigestible by humans because we to not produce the enzyme cellulase. Cellulase is produced by grazing animals such as cows (with the aid of the beneficial bacteria that reside in the animal's digestive tract), and is the reason why they can get nutrition from plants such as grasses. The human body does not produce cellulase, however, it is available for supplementation since it can help us break down plant material better, thereby getting the most from the plants that we eat.

Since enzymes play such a crucial role in our health, supplementing with enzymes is essential. Not all enzymes sold have the same activity, come from the same source, or are for digestion. Enzyme products made from animals are only as good as the animal it comes from, and the activity is variable. Animal enzymes break down differently during digestion than plant enzymes. Plant enzymes made from combined pure plant protein food in a laboratory setting and grown for specific needs are more capable of digestion replacement. To be clear, I am speaking of amylase, lipase, cellulase and protease plant enzymes grown in a laboratory from natural food sources grown specifically for digestive use. Amylase breaks down starch/carbohydrates, lipase breaks down fats, cellulase breaks down fiber and protease breaks down protein. Supplementing with plant enzymes is an investment in life and extends the food you eat since it doesn't just fill your stomach, but is broken down to fill your biochemical needs.