Mushrooms are a large group of fungi widely used for numerous benefits. They have anti-inflammatory benefits, rich nutritional values, anti-cancer properties, antioxidant qualities, etc. The oyster mushroom (Pleurotus sp.) is cultivated and consumed all over the world. People admire it for its unique taste, high nutritional value and health benefits. Pleurotus ostreatus became popular in Germany around 1917 and later it was discovered that several species can grow on agricultural wastes, lignocelluloses and forest-by products. There are many organic matters that can be cleverly used as substrates such as wheat straw, rice stalk and coco pet. However, the substrate porosity needs to be increased by adding gypsum. Usually, the substrate’s moisture should be kept around 60-75% and increased to 80-95% during fruiting.
One study used combinations of wheat straw and artichoke stalks for substrates. All mixtures were supplemented with 75g wheat brand and 30g of gypsum and afterwards moistened with 2,5 liters of water. The bags holding the different substrate mixtures were sterilized in an industrial autoclave for one and a half hour at 126 ºC under 1.5 A pressure. Prior to inoculation, they were allowed to cool. The growing room temperatures were between limits of 24-25 ºC. The relative humidity was set at 85%. The substrates used were three different mixtures of artichoke stalks and wheat straw, along with single wheat straw and single artichoke stalks. After performing different analyzes, the results indicated that the harvest time was highly different, shorter in artichoke stalks and artichoke stalks mixed with wheat straw than in wheat straw only (control lot). The highest yield was met when using 100% wheat straw. The best values for biological efficiency (66.41%) were also obtained with 100% wheat straw followed by a mix of 75% wheat stalks and 25% artichoke stalks with a value of 56.93%.
After gathering all the results, the conclusion was that regarding the biological efficiency, which is the most important parameter in mushroom growth, the highest and lowest values found in the experiment were 66.4% for 100% wheat stalk and 50.58% for 100% artichoke stalk. Therefore, artichoke stalk is a suitable candidate in the mushroom industry, but it is preferred to be used in mixtures for bringing its potential closer to the maximum.
Another experiment focused on using organic wastes, more precisely sawdust, cotton seed, wheat straw and paper waste to assess the production potential. The moisture content of the substrate had to be around 65 to 70%. Autoclave sterilization followed by several hours of cooling was mandatory before inoculating the spawn. Moreover, proper ventilation in the growth room was kept by occasionally opening the door. After the trial was done, mycelia growth was reported to be faster on cotton seed and paper wasted when compared to the other substrates. Also, pin-head formation took place rapidly in cotton seed. The time required by fruiting bodies to be matured enough varied from 27 days for cotton seed to 40.67 days for wheat straw. Records showed that product from paper waste knows a better growth in terms of thickness of the pileus and diameter. Furthermore, the number of fruiting bodies was higher in cotton seed than in other used substrates. The largest yield was harvested from cotton seed. The biological efficiency varied significantly. The highest percentage was present in cotton seed and the lowest in sawdust substrate. The conclusion from this study concerning oyster mushroom cultivation states that cotton seed and paper waste are suitable substrates.
Researchers in Taiwan compared three different substrates and combinations to study the effects, productivity, yield and biological efficiency. They used sawdust, corncob and sugar bagasse. All substrates were sterilized in an autoclave at 121ºC for 5h. The inoculated substrates were kept under dark conditions in an incubation room that provided a temperature of 28 ºC and 60-70 % relative humidity. This procedure was followed by a transfer to the cropping room where the humidity was increased to 90% and temperature was lowered to 24 ºC. After harvesting, the study showed a correlation between yield and biological efficiency. The substrate of 100% sawdust showed the lowest mushroom yield and the lowest biological efficiency. The highest values were recorded in 100% corncob (66.08%) and 100% sugar bagasse (65.65%). The differences can be blamed on the physical and chemical compositions of the substrates, pH, C/N ratio.
Higher biological efficiencies may be achieved trying different substrata and strains but still we need to look at several factors which in combination with a good strain could provide a biological efficiency of up to 200% which in some cases is known to occur for this mushroom. However, farm location remains an important point in getting higher mushroom crops and this needs to be analyzed by anyone wanting to grow oyster mushrooms for profit.
A report by Malina Puia
- A. Adebayo, J.K. Oloke, “OYSTER MUSHROOM (PLEUROTUS SPECIES); A NATURAL FUNCTIONAL FOOD”, 2017
- Girmay, et al., “Growth and yield performance of Pleurotusostreatus (Jacq. Fr.) Kumm (oyster mushroom) on different substrates”, 2016
- A. Nadir, “Effect of different substrates on the yield and quality of oyster mushroom (Pleurotusostreatus), 2014
- T. Hoa, et al., “The Effects of Different Substrates on the Growth,Yield, and Nutritional Composition of Two OysterMushrooms (Pleurotusostreatus and Pleurotuscystidiosus)”, 2015