CHANGES IN MACRONUTRIENTS AND PHYSICAL PROPERTIES DURING THE GROWTH OF Lentinula edodes AND Pleurotus ostreatus IN A COMPOST BASED ON SUGARCANE BAGASSE AGRICULTURAL WASTE

et al. Sci., Macronutrients and physical properties of sugarcane substrate after growth of Chilean J.Narváez Agric. Anim. ex Agro-Ciencia (2021) 37(3): 301-312. L. edodes and P. ostreatus https://doi.org/10.29393/CHJAAS37-31CMLO40031 301 ISSN 0719-3890 online CHANGES IN MACRONUTRIENTS AND PHYSICAL PROPERTIES DURING THE GROWTH OF Lentinula edodes AND Pleurotus ostreatus IN A COMPOST BASED ON SUGARCANE BAGASSE AGRICULTURAL WASTE Laura Narváez1a, Ana Cristina Bolaños1b*, Adriana Chaurra2, and Orlando Zuñiga Escobar3 Facultad de Ciencias Naturales y Exactas, Departamento de Biología, Grupo de Investigación en Biología de plantas y microorganismos (GPM), Universidad del Valle. Calle 13 No. 100-00, Cali, Colombia https://orcid.org/0000-0002-1808-851X 1b Facultad de Ciencias Naturales y Exactas, Departamento de Biología, Grupo de Investigación en Biología de plantas y microorganismos (GPM), Universidad del Valle. Calle 13 No. 100-00, Cali, Colombia https://orcid.org/0000-0003-0882-2351 2 Facultad de Ciencias básicas, Departamento de Ciencias Ambientales, Grupo de Investigación en Estudios Ambientales para el Desarrollo Sostenible (GEADES), Universidad Autónoma de Occidente. Calle 25, Vía Cali - Puerto Tejada #115-85 Km 2. Cali, Colombia https://orcid.org/0000-0001-62774245 3 Facultad de Ciencias Naturales y Exactas, Departamento de Física, Grupo de Investigación en Ciencias Ambientales y de la Tierra (ILAMA), Universidad del Valle. Calle 13 No. 100-00, Cali, Colombia https://orcid.org/0000-0003-4434-8597 * Corresponding author E-mail: 1a ABSTRACT Spent mushroom substrate of different edible mushrooms is a nutrient-rich biomass associated with mycelial metabolic activity in the growth substrate. The objective of this study was to evaluate the changes in the nutritional content and physical properties of a sugarcane bagasse substrate after the cultivation of the edible mushrooms Pleurotus ostreatus and Lentinula edodes. Strains of both species were first propagated in potato dextrose agar culture medium, then in wheat grains, and finally inoculated in sterile sugarcane bagasse. Determinations of macronutrients, pH and C:N ratio were carried out at 0, 30 and 60 days after mushroom mycelium growth in the bagasse-based substrate. After 30 and 60 days of inoculation, nitrogen (N), phosphorous (P) and potassium (K) recorded increases of 0.26%, 0.06% and 0.14 with Pleurotus ostreatus, and increases of 0.33%, 0.05%, and 0.11% with Lentinula edodes, respectively. Regarding micronutrients, there was an increase in Calcium (Ca) and Sulphur (S) in both substrates, but amounts varied during the time evaluated. Additionally, an important increase in hydrogen ion concentration was observed when both species were inoculated, with final values of 4.26 and 3.9 for Pleurotus ostreatus and Lentinula edodes species, respectively. In conclusion, this biomass presents a high percentage of the essential micro and macro elements required in a fertilizer. Key words: Biofertilizer, nitrogen, biomass, spent mushroom substrate. Received: June 28, 2021 Accepted: December 3, 2021 302 Chilean J. Agric. Anim. Sci., ex Agro-Ciencia (2021) 37(3):301-312. . INTRODUCTION Lentinula edodes and Pleurotus ostreatus, species of the Basidiomycota phylum, are among the five species with the highest market demand for edible fungi in the world (Royse et al., 2017). Mushroom sporocarps are characterized by their edible potential as they are a rich source of protein with high contents of essential amino acid, vitamin (B1, B2, B12, C, D, E), minerals, water and fiber as well as low levels of fat (Heleno et al., 2010; Ouzouni et al., 2009). In addition, sporocarps of many mushroom species are used for their medicinal value because of their active biological compounds with antibacterial, antifungal, antiparasitic, antidiabetic, antiallergic, anticholesterolemic, antioxidant, immunomodulating, and antitumor properties (Chang and Wasser, 2012; Sari et al., 2016). The world market for edible mushrooms was US $ 42,419 billion dollars in 2018, but is expected to grow to US $ 62,193 billion dollars in 2023 (https:// www.knowledge-sourcing.com/products/ global-edible-mushrooms-market-industrytrends-opportunities-and-forecasts-to-2023). This will result in an increased production of spent mushroom substrate (SMS) or spent mushroom compost (SMC), which is a by-product after the harvest of edible mushrooms (Owaid et al., 2017). This compost is made from agricultural waste such as tea leaves, banana, cotton, corn husk, coffee husks, sugarcane bagasse, cereal straw, and wood sawdust. In the cultivation of Agaricus spp., horse manure, chicken manure, urea, ammonium sulfate, blood meal, grape pomace, molasses, brewers’ grain and feather flour are added as supplements to increase soil nitrogen content (Stamets, 1983; Kamthan and Tiwari, 2017; PardoJimenez et al., 2016; Pardo-Jimenez et al., 2018). These substrates have high content of polysaccharide, vitamin, and trace elements, such as Fe, Ca, Zn and Mg (Medina et al., 2009; Zhu et al., 2012). They also have extracellular enzymes produced by edible fungi to carry out efficient lignin degradation (Pandey et al., 2014; Singh and Singh, 2012) as well as cellulose and hemicellulose degradation (Kabet et al., 2017; Vos et al., 2017). In China, which is the largest producer of edible fungi (Liu et al., 2015), it is estimated that 4-5 kg of SMC are generated for each kg of fungi produced (Law et al., 2003; Medina et al., 2012; Phan and Sabaratnam, 2012). SMC is reused in mushroom cultivation (Wang et al., 2015) and animal feed (Ayala et al., 2011; Kim et al., 2011; Chang et al., 2016; Foluke et al., 2014), and the enzymes can be recovered (Phan and Sabaratnam, 2012; Rodriguez et al., 2012; Lim et al., 2013; Raymond et al., 2015). In fact, the substrate is used as a substitute for peat (Abad et al., 2001) in bioremediation (Stanley et al., 2018; Marin-Benito et al., 2016), and for bioethanol production (Hiyama et al., 2011), pest management (Ahmad et al., 2016), and packaging and construction materials (Appels et al., 2018; Xing et al., 2018; Jones et al., 2017). SMC is also used as a soil conditioner and for the recuperation of degrade soils in agriculture (Gümüs and Seker, 2017; Jankowski et al., 2018; Unal, 2015). In this sense, the addition of depleted compost to the soil can result in positive effects such as the development of a granular microstructure in the A horizon and a spongy structure in the B horizon (Nakatsuka et al., 2016), and also increased biological activity (Balesdent et al., 2000), where fungi play an important role because they modulate soil strcuture. As the hypha grow, they stabilize, agglutinate, and decompose organic matter (binding soil grains into granular aggregates), and realign particulate materials on a micrometric scale (Tisdall and Oades, 1982; Ritz and Young, 2004). According to Gümüş and Şeker, (2018), addition of spent compost to the soil improves (...truncated)