First successful cultivation and nutritional composition of Macrocybe gigantea in Sri Lanka

The wild edible mushroom Macrocybe gigantea is widely consumed as one of the prime seasonal delicacies in the tropical and subtropical regions of the world. In this study, M. gigantea was identified through morphological and phylogenetic analyses. Spawn production and cultivation parameters of M. gigantea were investigated for the first time in Sri Lanka. The mycelial growth was observed in potato dextrose agar medium, while paddy grains were used for spawn production. A mixture containing rubber sawdust (100 kg), rice bran (18 kg), CaCO3 (2.5 kg), gypsum (1 kg), and MgSO4 (0.35 kg) was tested as a substrate for colonization bags. In addition, gene sequence-data, proximate analysis, energy value, and mineral elements of cultivated M. gigantea were studied. Mycelia in mushroom growth bags were cultivated under the temperature range of 27–30 ℃ and relative humidity of 60 %. Three weeks after inoculation, the primordia appeared and it ook four additional days until the occurrence of young fruit bodies. A second flush was harvested 3 weeks after the first. Proximate analysis, energy value and mineral element analysis were recorded as 85.3 % moisture, 0.8 % ash, 1.6 % fat, 2.3 % protein, 10.0 % carbohydrate, 0.28 % potassium (K), 0.00064 % iron (Fe), 0.0024 % sodium (Na), and energy 63.6 kcal/100g. This study provides valuable information concerning the cultivation and nutritional composition of M. gigantea in Sri Lanka.