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.
Industrial fermentation is the intentional use of fermentation by microorganisms such as bacteria and fungi to make products useful to humans.Fermented products have applications as food as well as in general industry. Some commodity chemicals, such as acetic acid, citric acid, and ethanol are made by fermentation.n the process of sewage treatment, sewage is digested by enzymes secreted by bacteria. Solid organic matters are broken down into harmless, soluble substances and carbon dioxide. Liquids that result are disinfected to remove pathogens before being discharged into rivers or the sea or can be used as liquid fertilizers.