Cultivation of Oyster Mushroom - Iloka Benneth Chiemelie

CHAPTER 1

INTRODUCTION

1. Background

With their great variety of species, mushrooms are cost-effective means of enhancing human nutrition. Up to 5 species of mushroom are used for industrial production across the world (Chang and Miles, 1991). For instance in India, only 3 species of mushroom, namely, Agaricus bisporus, Pleurotus sajorcaju and Volveriell are commonly used for commercial cultivation. Out of the three most used species, the white button mushroom is the most preferred amongst consumers and account for 90 percent of total mushroom production in the India. Across the globe, different kinds of mushroom are also demanded both for commercial and individual production.

The Oyster mushroom grows during winter months only, thus it is necessary to properly preserve them in order to promote their consumption people at periods when they are not growing. It can also be processed into food products that are common to consumers. Mushrooms generally contain 90 per cent moistures.

Oyster mushroom (Pleurotus sp.) belong to the Class Basidiomycetes and Family Agaricaceae and grows naturally in temperate and tropical forests, on dead and decaying wood logs, dying tanks of deciduous or coniferous woods. Oysters mushroom are the third largest cultivates mushroom in the world and they are rich in protein (Sonali, 2010). It can also grow on decaying organic matters. The economic importance of mushroom is mainly on its human consumption as foods. It is also rich in Vitamin C and B complex, and mineral salts. It contains niacin which is at least 10 percent higher than other vegetables.

Oyster mushroom also contains folic acids that can be used to cure anaemia. It has been described as suitable for people with hyper-tension, obesity, and diabetes as it is low in sodium, potassium, starch, fat and calorific value (Sonali, 2010).  Alkaline ash and high fibre content also make then good for consumption for people suffering from hyperacidity and constipation, and cholesterol related health issues. 

Generally, mushrooms are high sources of vitamin D and conjugated linoleic acid. The presence of Ergothioneine makes them natural antioxidants. For Oyster mushroom to grow properly, a moderate temperature ranging from 20 to 300 C and humidity 55-70% for a period of 6 to 8 per annum is required. It can also be cultivated in summer times at hilly areas above 900m where the humidity required for its growth is present. This study will observe growth of oyster mushroom on different raw material, nutritional qualities of oyster on different raw material and physico-chemical characteristics of oyster mushroom.

1.2 Importance of study

Considering the nutritional and economic value of cultivating mushroom as discussed in the background above, this study is significant for a number of reasons:

1.2.1 To biotechnologist, biochemists and agriculturist – this paper is important because it will discuss the best approaches to cultivate Oyster mushroom and ways cooperation can increase their yield by adopting numerous agricultural technologies. Although mushroom is widely consumed across the globe, not all the consumers understand the significance of such consumption and economic value it has on their lives. Thus, this paper will also explore this are by providing farmers with new ways to successful cultivate and market Oyster mushrooms.

1.2.2 To producers and consumers – it was widely discussed in the above background that Oyster mushrooms are used for commercial productions such as foods which are commonly consumed by human beings. Thus, this paper is significance for producers and consumers because it will equip producers with new knowledge and skills to enhance their production and meet customers’ demand, while it will also help in educating customers about the importance of consuming mushroom and persuade them to enhance their demand for Oyster mushroom as it is a healthy food.

1.3 Research purpose

The purpose of this research is to understand how Oyster mushrooms are cultivated, and in the case of doing such, this paper will address the following questions:

1. What are the necessary equipment and techniques for cultivating Oyster mushroom?
2. What are the right humidity, temperature and soil for cultivation of Oyster mushroom?
3. What are the right technologies to enhance production?
4. How can Oyster mushroom be consumed and what are the nutrition values?

1.4 Limitations

Although all necessary efforts will be put into this paper, to ensure that the objectives of this paper is meet, it must be acknowledged that there is nothing like a perfect research. Thus, this thesis will be lacking in certain areas such as:

1.4.1 Focus on specific tools, equipment and technologies – the production approach used will focus only on specific technologies as it will be impossible to touch all the technologies that are used for production of Oyster mushroom across the world. The reason for this limitation is that agricultural production varies across countries and traditions, and it is virtually impossible for this paper to address all the equipment, tools and technologies used in production of Oyster mushroom and other forms of mushroom across the world.

1.4.2 Focused only on Oyster mushroom – there are different kinds of mushroom as illustrated in the background analysis above, and at least 5 of these kinds of mushrooms are used heavily for industrial production. In India for examples, the most consumed mushroom is white button mushroom. However, this paper focuses only on Oyster mushroom and this is a limitation because it doesn’t offer readers the opportunity to understand production techniques and consumption value of other forms of mushroom.

1.5 Organization of study

Figure (1): how the thesis will be conducted  

CHAPTER 2

LITERATURE REVIEW

2.1 Chapter introduction

In this chapter, this paper will analysis all production approaches used for cultivation of Oyster mushroom and other forms of mushroom. While this chapter will address other forms of mushroom, it is important to note that the focus will be on cultivation of Oyster mushrooms. In the process of doing so, this chapter will highlight the soil, temperature, and humidity requirement as well as other factors that can influence growth in production of mushroom. Additionally, this chapter will also attempt to apply these production processes in different countries and geographical location.

2.2 Framework for review

Figure (2): framework for the literature review

For this study, corn cob and rice husk will be used as the substrate for cultivation of Oyster mushroom. As such, the literature review will focus on these two substrates.

Cultivation of Oyster Mushroom

Naturally, mushrooms grow in filed, forest, manure heaps, water channels and hilly areas, mainly during rainy periods. The most popular species are: Agaricus bisporus (European or white button mushroom), Pleurotusspp., (Oyster mushrooms or dhingri), Volvariella volvacea (Chinese or paddy straw mushroom) Lentinus edodes (Shiitake mushrooms) andAuricus laria (Black ear mushroom).

Oyster mushrooms grow under natural conditions such as living trees as parasites or dead woods as saprophyte and primary decomposers. A fresh fruiting body of Oyster mushroom has a chemical composition that indicates high quantity of moisture (90.8%), whereas fresh as well as dry oyster mushrooms are rich in proteins (30.4%), carbohydrates (57.6%), fat (2.2%), fiber (8.7%) and ash (9.8%) with 345 K (cal) energy value on 100 g dry weight basis; it also contains vitamins such as thiamin (4.8 mg), niacin (108.7 mg) and riboflavin, minerals like calcium (98 mg), phosphorus (476 mg), ferrous (8.5 mg) and sodium (61 mg) on 100 g dry weight basis (Pandey & Ghosh, 1996). Rambelli & Menini (1985) stated that Oyster mushroom is reputed to be antitumoural as a result of these chemical compositions.

Oyster mushrooms can be cultivated in semi-controlled conditions by using agricultural or industrial wastes and other refuses as substrate.Badshah et al., (1992) grew Pleurotus ostreatus on wheat straw, sugarcane bagasse, corn cobs or sawdust by mixing 120-130 g of spawn with 2 kg of and putting the mixture in a sterilized polyethylene bags and left it in a dark room at 25OC for 2-3 weeks. They harvested the fruiting bodies at maturity and it had a yield rate of 49.8 g/2 kg with sawdust as substrate, 432.8 g/2 kg with wheat straw as substrate, and those grown in the filed yielded only 18.5 g/2 kg from the same substrate.

For proper growth, a dark cool and moist room is necessary as illustrated from the finding above. Additionally, Mushrooms grown normally in cellulose-rich materials because it is a fungi and need the yeast products from decomposition in order to aid growth. The presence of moistures helps in increase the body mass of mushroom.

Corn cob as substrate for cultivation of Oyster Mushroom

Margaret (2012) stated that farmers are skeptical about removing crop residue from their farm because it can significantly increase the nutrient of the soil if it is left to decay. However, she stated that there are many questions concerning the nutrient level that a crop residue can increase in a soil. Such questions lead to his article to understand the importance of removing corn cobs from farmers.

A corn plant is made up of numerous parts like: stalks, husks, shanks, silks, leaf blades, leaf sheaths, tassels and cobs (Margaret, 2012). Most of these parts are left in the field once the grains have been harvested (Kludze et al., 2010). Corn cob has been identified to contain high moisture and large amount of potassium and chloride (Margaret, 2012). Since corn cobs contain high moisture, they aid decomposition and releases cellulose during the decomposition process.

Margaret (2012) also identified other common micronutrients in corn cob that are necessary for mushroom growth and production. These micronutrients are as illustrated in figure (3) below.

Figure (3): Micronutrients present in corn cob

Source as adapted from: Margaret (2012).

From the figure (3) above, it can be seen that contains calcium and magnesium which are necessary for growth of Oyster mushrooms. Combing these micronutrients with potassium, chloride and high moisture present in corn cob, it can easily be deduced that this is a worthy substrate for production of Oyster Mushroom. The reason is that it aids decomposition, and in the process of decomposition, corn cob produces cellulose which is deemed necessary for the growth of Oyster mushrooms.

Rice husk as substrate for cultivation of Oyster Mushroom

Rice is one of the most staple foods across the world and is consumed by over 50% of the world’s population. Most of the people who depend on rice as a source of food live in Asia and Africa (Frimpong-Manso et al., 2011). Rice husk is a by-product of rice, and it account for 235 of total paddy weight after harvest. In is used for different purpose across the globe. For instance, it is used as biomass fuel in Thailand, in the country’s fight to help reduce energy usage and safe the planet (Shashirekha et al., 2005). However, rice husk has been identified as rich in cellulose (Datta and Chakravarty, 2001; Obodai et al., 2003).

Naturally, mushrooms are grown on numerous substrates, and the choice of substrate depends on availability and cost. Mushrooms also convert cheap cellulose into valuable protein (Poppe, 2000). In this case, it has once more been revealed that rice husk just like corn cob is rich in cellulose which is the main nutrient for growth of mushroom.

From the above analysis, it is now justifiable to state that the choice of corn cob and rice husk as the substrate for cultivation of mushroom in this paper is worthy because they both contain cellulose which is necessary for the cultivation and growth of mushroom. Additionally, corn cob is rich in moistures, and when wetted up, rice husk is can retain moisture for  a long period of time.         

2.4 Key findings from literature review

From the review of literature above, the nutrient contents of Oyster mushroom has been identified as the necessary conditions required for cultivation highlighted. The main findings are that Oyster mushroom can be grown with a number of substrate, and the choice of substrate depends on availability and price. Most of the substrates as highlighted by the finding are wood and agricultural products. Thus, this makes agricultural products of high importance in cultivation of Oyster mushrooms.

Additionally, cellulose rich materials were singled out as the main characteristic a substrate must possess in order to be deemed fit for the cultivation of Oyster mushroom. This is because Oyster Mushrooms belong to the fungi kingdom and as such require cellulose which is usually produced in decomposition for survival and growth.

For this paper, the substrates chosen for cultivation are corn cob and rice husk. From the analysis, both of these substrates were identified to be rich in cellulose which is vital for growth of Oyster Mushroom. The main reasons why these substrates are rich in cellulose is because they contain and retain high volume of moistures, and are biological waste products which are naturally used by farmer to increase the fertility of their farm land. Thus, it is justifiable to choose these substrates because they are guaranteed to yield the most effective and efficient growth as will be illustrated in the findings later. Additionally, these substrates have been tried by researchers in the past, and they found that it yielded more output that those planted under normal agricultural conditions when grown in dark rooms. Thus, the last finding from this literature review is that dark rooms and cool temperatures are necessary for more productive growth.

References

Badshah, N., N. Ur-Rehman and M. Wahid. 1992. Yield and quality of mushrooms grown on different substrates. Sarhad J. Agriculture, 8(6): 631-635.

Chang, R. 1996. Nutrition Reviews. 54: 91-93.Chorvathoba, V., Bobek, P., Ginter, E. & Klavanova, J. 1993. Physol. Res. 42:175-179.

Datta, S and Chakravarty, D. K. 2001 Comparative utilization of lignocellulosic components of paddy straw by Tricholoma lobayense and Volvariella volvacea. Indian Journal of Agricultural Sciences 71 (4): 258-260.

Frimpong–Manso, J., Obodai, M., Dzomeku, M. and Apertorgbor, M. M.(2011), “Influence of rice husk on biological efficiency and nutrient content of Pleurotus ostreatus (Jacq. ex. Fr.) Kummer.” International Food Research Journal 18: 249-254. Available at:http://www.ifrj.upm.edu.my/18%20(01)%202011/(24)_IFRJ-2010-028_Mary_Ghana[1].pdf [Accessed on: 25/02/2013].

Kludze, H., Deen, B., Weersink, A., van Acker, R., Janovicek, K., De Laporte, A. 2010. Assessment of the availability of agricultural biomass for heat and energy production in Ontario. (http://www.uoguelph.ca/plant/research/agronomy/publications/pdf/Ontario_Biom ass_Availability_Project_Final_Report_2011.01.27.pdf).

Margaret, R. (2012), “Nutrient Content of Corn Plant Parts.” Available at:http://www.ifao.com/PDFs/Nutrient%20Content%20FINAL%20IFAO.pdf[Accessed on: 25/02/2013].

Obodai, M., Cleland-Okine, J. and Vowotor, K. A. 2003. Comparative study on the growth and yield of Pleurotus ostreatus mushrooms on different lignocellulosic by-products. Journal of Industrial Microbiology and Biotechnology 30 (3): 146-149.

Pandey, R. S. and S. K. Ghosh. 1996. A Handbook on Mushroom Cultivation. Emkay publications, Delhi. pp. 134.

Poppe, J. 2000. Use of agricultural waste material in the cultivation of mushrooms. Mushroom Science 15: 3-23.

Rambelli, A. and U.G. Menini, 1985. Manual on mushroom cultivation. FAO Plant Production and Protection paper: 43 pp.65.

Shashirekha, M. N., Rajarathnam, S and Bano, Z. 2005. Effect of supplementing rice straw growth substrate with cotton seeds on the analytical characteristics of the mushroom, Pleurotus florida (Block and Tsao). Food Chemistry 92(2): 255-259.

Sonali, D.R. (2010), “Cultivation and study of growth of oyster mushroom on different agricultural waste substrate and its nutrient analysis.” Department of Biotechnology, Walchnad College of Art’s & Science Solapur, India.