1) incomplete path of respiration in the absence of sufficient oxygen. 2) the conversion of organic substances to alcohol and other metabolites by the action of enzymes (or ferments) that may invade a tree’s vascular system. The reaction may be aerobic or anaerobic. depending on the microorganisms or enzymes used.
Fermentation is a type of redox metabolism carried out in the absence of oxygen. During fermentation, organic molecules (e.g., glucose) are catabolized and donate electrons to other organic molecules. In the process, ATP and organic end products (e.g., lactate) are formed.
Because oxygen is not required, it is an alternative to aerobic respiration. Over 25% of bacteria and archaea carry out fermentation, and they live in the gut, sediments, food, and other environments. Eukaryotes, including humans and other animals, also carry out fermentation.
Fermentation is important in several areas of human society. Humans have used fermentation in production of food for 13,000 years. Humans and their livestock have microbes in the gut that carry out fermentation, releasing products used by the host for energy. Fermentation is used at an industrial level to produce commodity chemicals, such as ethanol and lactate. In total, fermentation forms more than 50 metabolic end products with a wide range of uses.