Development of low-cost cultivation protocol for Ganoderma lucidum (Curtis)

Introduction

Mushrooms are considered ultimate healthy food and dietary supplements. They contain proteins, carbohydrates, minerals, vitamins, saturated fatty acids, phenolic compounds, tocopherols, ascorbic acid and carotenoids (Ho et al., 2020). Thus, mushrooms can be used directly in the diet and promote health, taking advantage of both the additive and synergistic effects of all bioactive compounds present in it (Reis et al., 2011).

The cultivation of edible mushrooms could become a way to augment farm income while making use of crop-based residues. The growth of a variety of mushrooms requires different type of substrates and availability of different type of materials. Substrates such as logs, wood sawdust, rice straw and hull, banana leaves, maize stalk, and various grasses can all support mushroom growth (Philippoussis, 2009). In some parts of the Philippines, these substrates may not be available or are available at relatively high prices. Thus, mushroom growers are continuously searching for alternative substrates that may be more readily available or cost effective, or that may provide higher yield and better mushroom quality (Royse D et al., 2004).

Ganoderma lucidum (Curtis) P. Karst is a tropical, edible mushroom that is commonly known as "Reishi" in Japanese and "Lingzhi" in Chinese (Yang and Liau, 1998; Wagner et al., 2003). World-wide, Lingzhi occupies a major source of medicine that has been used for more than 2000 years (Azizi et al., 2012). Commercial G. lucidum products are available in various forms, such as powders, dietary supplements, and tea which are obtained from different parts of the mushroom, including mycelia, spores, and fruiting body (Wachtel-Galor et al., 2011). To meet the gradually increasing demand for G. lucidum as a natural medicine, commercial cultivation of this mushroom has been initiated worldwide, especially in the tropical Asian countries (Chang and Buswell, 2008). As different members of the Ganoderma genus seek different conditions for growth and cultivation, and the traditional cultivation technique takes several months for fruiting body development, artificial cultivation of G. lucidum has been implemented using the available substrates such as grain, sawdust, wood logs and cork residues (Boh et al., 2007). Several substrates have been investigated worldwide for the cultivation of G. lucidum (Tiwari et al., 2004).

With the need to cultivate G. lucidum using lowcost inputs and locally available materials, this project envisioned to determine the best culture media, grain and substrate in terms of biological and cost efficiency. Discovering the best culture media, grain and substrate for G. lucidum may lead to the development of mushroom production technologies that may increase yield, and in effect further increase farmers' income.