Two-steps Utilization of Shorea Wood Waste Biomass for The Production of Oyster Mushroom and Biogas - A zero waste approach

Two-steps utilization of residual Shorea wood biomass (Meranti) from saw mill industry in Balikpapan, East Kalimantan, Indonesia was studied to point out its potential as the feedstock for the production of food and energy. For this purposes, oyster mushroom, Pleurotus ostreatus was cultivated on mixed sawdust of Shorea wood (major species; Shorea leprosula), and then the residual wood obtained from mushroom production (spent waste) was subjected to methane fermentation by mixing with cow dung in two steps utilization process. The effects of the bio treatment on biogas production and correlation with compositional changes in the wood by mushroom cultivation were evaluated. P. ostreatus preferentially decomposed lignin in the tropical wood with high productivity of matured fruiting body. During 44 days, fruiting bodies were harvested and collected four times, and lignin and holocellulose in the Shorea wood decreased by 24.7% and 15.8%, respectively. Biological activity expressed as yields of the fruiting body was the maximum at the first flush, and decreased gradually. In methane fermentation, addition of pretreated wood waste increased production of biogas by 2-3 times higher than those without the bio-treated wood. The combination of mushroom and biogas production of residual Shorea wood biomass creates a new industrial application of unutilized wood biomass from tropical rainforests, with a great deal of advantages supplying value-added foodstuff and also renewable energy for the local community. (C) 2016 The Authors. Published by Elsevier B.V.