Final answer:
Fungi use the enzyme cellulase to digest cellulose by breaking down its ß-glycosidic linkages into glucose. These enzymes support the role of fungi as decomposers and are useful in bioremediation.
Step-by-step explanation:
The key enzymes used by fungi to digest cellulose are primarily various forms of the enzyme cellulase. Fungi, which are often saprobes, produce these enzymes to break down the polysaccharide cellulose, a major component of plant cell walls, into smaller, absorbable glucose molecules. The high surface area-to-volume ratio of fungal hyphae aids in the absorption of these nutrients. Through the secretion of hydrolytic enzymes, fungi can degrade complex organic molecules like polysaccharides, proteins, and lipids into simple molecules that can then be absorbed by the fungal cells. The enzyme cellulase specifically hydrolyzes the ß-glycosidic linkages of cellulose, which are highly stable and cannot be digested by human enzymes. However, this ability is crucial for the decomposition of organic matter in ecosystems, and certain fungi are also being researched for bioremediation purposes, including the breakdown of pollutants like diesel oil and polycyclic aromatic hydrocarbons.