Mushroom as an excellent food source due to their flavor, texture, nutritional value and high productivity per unit area. Mushroom contains digestible proteins (10%-40%), carbohydrates (3%-21%), dietary fiber (3%-35%), on dry weight basis which is higher than those of vegetables and fruits and is of superior quality. High potassium to sodium ratio contain in Pleurotus species helps to cure patients suffering from hypertension & heart diseases. There are several species of Pleurotus identified in the world. Most of them are suitable for cultivation. Some Pleurotus species are Pleurotus ostreatus, Pleurotus columbinus, Pleurotus florida, Pleurotus salignus, Pleurotus spodoleucus, Pleurotus pulmonarius; and sub-species are Pleurotus sajor-caju, Pleurotus sapidus, Pleurotus populinus, Pleurotus cornucopiae, Pleurotus djamor, Pleurotus flabellatus, Pleurotus eryngii, Pleurotus cystidiosus, Pleurotus calyptratus, Pleurotus dryinus, Pleurotus purpureo-olivaceus andPleurotus tuber-regiu.
Difference in mycelium extension, mineral content and yield of mushroom not only depended on mushroom species but also depended on substrates used. The fruiting body of oyster mushroom differs with respect to stipe length and girth, and pileus width when grown in different substrates.
Most organic matters containing cellulose, hemicelluloses and lignin can be used as mushroom substrate i. e. rice and wheat straw, banana leaves, cottonseed hulls, corncob, sugarcane baggase, sawdust, waste paper, leaves, and so on. The amount of nutrition requirement differs according to mushroom species and types of substrate used. A lot of edible mushrooms have also proven to be able to degrade lignocellulosic materials. the ligninolytic enzymes system of edible mushrooms may be used for the recycling of a lot of worldwide agro-industrial wastes, depending on the local availability of agricultural and food residues. Mushrooms produce a number of enzymes including lignin-degrading enzymes (laccases, lignin peroxidases, manganese peroxidases, arylalcohol oxidase, aryl-alcohol dehydrogenases or quinone reductases), and hemicellulose and cellulose-degrading enzymes (xylanase, cellulases or cellobiose dehydrogenase), to facilitate the degradation of lignocellulosic substrates.
Ecological requirements of oyster mushrooms vary at the various stages of growing period. The optimal temperatures for growing mycelia and pin forming are between 20 to 30 oC and 10 to 20 oC respectively. Substrate moisture should be 60 to 75%, but it should be 80 to 95% during the fruiting, because 80% or over of the fruit body is water (Nadir et al, 2016).
Mushroom supplementation is an agronomic process which consists of the application of nutritional amendments to the substrates employed for mushroom cultivation. Different nitrogen and carbohydrate rich supplements have been evaluated in crops with a substantial impact on mushroom yield and quality. The addition of external nutrients increases the productivity of some low-yielding mushroom varieties, and therefore is a useful tool for the industry to introduce new commercially viable varieties. The use of low-cost agricultural by-products available at the productive regions is a promising approach. Among others, cereal meals and brans, chicken manure, cottonseed meal, urea, superphosphate, ammonium sulphate, grape pomace, feather flour or defatted meals from dry nuts, are recognized as active ingredients to supplement substrates employed in mushroom cultivation in Brazil or Europe.