Changes in macronutrients and physical properties during the growth of Lentinula edodes and Pleurotus ostreatus in a compost based on sugarcane bagasse agricultural waste

Abstract

The spent mushroom substrate of edible mushrooms is a nutrient-rich biomass, derived from mycelial metabolic activity in the growth substrate. The main objectives of this study were to evaluate the changes of macronutrients and physical properties of the substrate after the cultivation of the edible mushrooms Pleurotus ostreatus and Lentinula edodes. Strains of these two species deposited in the fungi cultivation collection of the biology department at the University of Valley in Colombia were first propagated in the potato dextrose agar culture medium, then in grains of wheat and finally inoculated in sterile sugar cane bagasse. Macronutrients, pH and C/N relation analyzes were carried out at the beginning, 30 and 60 days after mushroom mycelium growth in the bagasse-based substrate. The results obtained showed and increase of 0,26% of Nitrogen (N), 0.06% of phosphorous (P), 0.14 of potassium (K) 30 and 60 days after the substrate had been inoculated with Pleurotus ostreatus. In Lentinula edodes there was an increase of 0,33% in N, 0,05% in P, and 0,11% in K. In relation to the micronutrients in both substrates, there was an increase in Calcium (Ca) and sulphur (S), although amounts varied during the time evaluated. Additionally, a definite increase in hydrogen ion concentration was observed when both species were inoculated, obtaining 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.