1 Obligate aerobes: They have absolute requirement for oxygen in order to grow. 2  Psuedomonas aeruginosa, Mycobacterium tuberculosis. 3  Anaerobes: Usually can not grow in the presence of oxygen. 4  Obligate anaerobes: These bacteria grow only under condition of high reducing intensity and for which oxygen is toxic.
Wild yam is a plant. It contains a chemical, diosgenin, which can be made in the laboratory into various steroids, such as estrogen and dehydroepiandrosterone (DHEA). The root and the bulb of the plant are used as a source of diosgenin, which is prepared as an âextract,â a liquid that contains concentrated diosgenin.
Yams are the source of the chemical diosgenin, a precursor of progesterone, cortisone, and other medically important steroids. The collection of plants for the production of diosgenin is licensed in several parts of the world. The true yam is about 20 percent starch and as a food is very similar to a potato.True yams (Dioscorea spp., Dioscoreaceae) are the third most important tropical root crop after cassava (Manihot esculenta, Euphorbiaceae) and sweet potato (Ipomoea batatas, Convolvulaceae).he water yam is a species from south-eastern Asia that is commonly cultivated. The Chinese yam, or Chinese potato, also known as cinnamon vine, is cultivated as an ornamental climbing vine but is also an important food plant; its thick tubers reach a length of about 1 m (3 ft).