Coitus interruptus, also known as the withdrawal. method, is the oldest form of male contraceptive. method to be practiced.[1] It involves the male partner. pulling out the penis before ejaculation.[1] Even though. it is the oldest method of male contraception to be. practiced, research has given it very little attention.
Updated September 18, 2016. Fermentation is an energy-yielding anaerobic metabolic process in which organisms convert nutrients (typically carbohydrates) to alcohols and acids (lactic acid and acetic acid). Fermentation is perhaps the most ancient biotechnological discovery.
Fermentation is a metabolic process that converts sugar to acids, gases or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.ermentation takes place in the lack of oxygen (when the electron transport chain is unusable) and becomes the cellâs primary means of ATP (energy) production. It turns NADH and pyruvate produced in the glycolysis step into NAD+ and various small molecules depending on the type of fermentation (see examples below).