The Oyster Mushroom (Hiratake, Píng Gū, 平菇)
This mushroom also known as Pleurotus Ostreatus is close relative to the King Oyster mushroom. Other names that have been used to refer to this mushroom are Tree Oyster, Oyster Shelf, Straw Mushroom and Tamogitake. The Japanese on the other hand call it Hiratake, which means the ‘flat mushroom’.
It is grows wildly in forests found in sub-tropical and temperate climates. It is saprotrophic and is responsible for decomposing deciduous trees particularly the Beech tree. Amazingly, this mushroom is also carnivorous. Its victim is the nematode, an animal that is itself parasitic. Here seems a healthy way to control a pest without using a chemical pesticide. The Oyster mushroom is thought to obtain its nitrogen from the nematodes that it devours.
The Oyster Mushroom as a Dish
This mushroom is found in Chinese, Korean and Japanese menus. It is cooked in soups, soy sauce and other dishes. Often, it makes its own dish. Its taste is mild and it smells like anise. It is picked young for the kitchen because when it becomes tougher as it grows and its taste and smell deteriorate. In India, and particularly Kerala, the Oyster Mushroom is farmed extensively and the people there make a wide range of dishes from it. They usually grow it using modern methods where they put hay in clear polythene bags and shed spores within layers of hay. It is said to be the easiest to grow. The mushroom is said to have Arabitol, a sugar that can be a cause of gastrointestinal upset to some people.
Other Uses of the Oyster Mushroom
According to Natalie Rodriguez This Old House magazine, the Oyster Mushroom can make insulation and packaging material. Though not yet done on a large scale, this potential is encouraging in this era of environmental consciousness. And according this website, the Oyster mushroom can disintegrate disposable diapers. It may be able to do the same to oil spills and absorb it. This could revolutionise the safety of marine life. This should be of interest to BP!
Medicinal Properties of the Oyster Mushroom
The Oyster Mushroom has statins and lovastatins that help in lowering cholesterol in the body. Cholesterol as a word was formed from the Greek language. Chole means bile; stereos means solid; and ol is a suffix derived from the word alcohol.
The body has 2 types of cholesterol - the good and the bad. The good cholesterol is the high density lipoprotein, HDL, while the bad cholesterol is the low density lipoprotein, LDL. It is possible to know the level of each through a blood test. LDL is deemed bad because as it moves along with the blood, it leaves deposits on the walls of blood vessels. Gradually it forms a kind of plaque that narrows down the blood vessels. This condition is called atherosclerosis. Should there be a blood clot within the narrowed vessels then the person is likely to suffer a heart attack or even a stroke.
HDL, on the contrary is thought to clear some of the LDL ferrying it to liver for disposal. The Oyster Mushroom has lovastatin, a cholesterol lowering agent. It is in the category of drugs called statins. Lovastatins were identified in the 1970s. In 1982, tests on high risk patients proved successful and in 1987 the US FDA approved it.
Medics, and particularly the American Heart Association recommend that people should have a cholesterol check. The association says it is important that every person over 20 years of age has a Lipid Profile. This is a simple blood test to establish the level of bad cholesterol in the blood. A person going for the cholesterol check needs to fast for a period of between 9-12 hours to ensure that the fat picked up is really the one established in the blood.
The Oyster Mushroom also has some bacteria fighting substances. In 1950, pleuromutillin, an antibiotic developed from the mushroom, was found to kill various bacteria including the bacterium salmonella. Pseudomonas is another bacterium that pleuromutillin was able to wipe out. A more recent research, (Stamets, 2005) found that Pleurotus ostreatus, which are extracts from the Oyster Mushroom, are able to weaken the bacteria Staphylococcus aureus and Escherichia coli. From a concentration of 100 000 000 per millilitre, the bacterial concentration dropped to a mere 1 000 per millilitre within a span of 24-72 hours.
The Oyster Mushroom has the scent of anise because it has benzaldehyde. Benzaldehyde is an organic compound which is widely sought for industrial use. Martres, a Frenchman and pharmacist, was the first to extract this compound from a natural plant. He did that in 1803. Thereafter, in 1832, two German chemists, Friedrich Wohler and Justus von Liebig, synthesized it. Because of its nice scent, pharmaceuticals use it a lot.
The uses of the Oyster Mushroom are evidently varied, ranging from the kitchen and the farm, to pharmacies and industries where its potential is yet to be exploited.
Health Benefits of Oyster Mushrooms