Evaluation of mother spawn production of Volvariella volvacea (paddy straw) mushroom on different substrate for rapid Mycelium growth

Abstract

Mother spawn production is an essential source for the development of mycelium growth which will lead to the productivity of the fruiting body of straw mushroom in both quantity and quality. This study aimed to evaluate which substrates produces rapid mycelium growth rate of straw mushroom. Malt Extract Agar (MEA) was found to produce the fastest V. volvacea mycelium as compared to Potato Dextrose Agar (PDA) and Nutrient Agar (NA). Generally, the mycelium growth of straw mushroom in MEA was 2 days faster than PDA, while NA has no growth of mycelium at all. By comparing the mycelium growth rate of paddy rice, paddy straw (PS), rubber wood sawdust (RSD), non-composted empty fruit bunches (EFB) and composted EFB, RSD was found to produce rapid mycelium growth rate. Thus, optimization of RSD with the parameters temperature, amount of rice bran and calcium carbonate (CaCO3) was carried out using Box-Behnken design (BBD) of Response Surface Methodology (RSM). The optimum conditions obtained after optimisation studies depicts that at 34 ˚C, 0.5 g rice bran and 0.07 g of CaCO3. The solution of validation test obtained from experiment was close to the predicted value given by BBD with days taken for V. volvacea mycelium fully colonization on RSD substrate of 5.82 days versus predicted value of 5.89 days. The error was small thus the model was suitable to use for the optimization of Days taken for V. volvacea mycelium fully colonization on RSD substrate. The total lignocellulosic of paddy straw was found to be 11.87 % extractives, 20.84 % hemicellulose, 34.12 % cellulose, 10.58 % lignin and 22.51 % ash and , it was found out that the total days taken for V. volvacea mycelium to fully colonize the substrate paddy straw in “bongkah” was 10 days while for non-composted EFB was 12 days. The result attained from this study shows that rubber wood sawdust has the potential to become the alternative substrate to produce rapid mycelium growth.