Upcycling from chitin-waste biomass into bioethanol and mushroom via solid-state fermentation with Pleurotus ostreatus

Abstract

• Pleurotus ostreatus pretreatment of chitin waste biomass. • Eco-friendly depolymerized chitin technology. • Increased efficiency of chitin biomass saccharification. • Process integration of bioethanol production and food waste management. This study aimed to bioconvert of chitin waste biomass into oyster mushroom food and bioethanol through solid-state fermentation with Pleurotus ostreatus . The biological efficiency of the different recipes ranged from 75.66% to 130.61%. Three kinds of greenhouse gases (CO 2 , CH 4 , and N 2 O) were detected during oyster mushroom cultivation, whereas control group had 17.9% higher CO 2 emissions than the shell waste-based formulas. The nutrient enrichment capability of fruiting bodies was demonstrated as follows: N (0.33)＞P (0.24)＞C (0.1). Among the four shell waste recipes, 50% crayfish shell and 50% chestnut hull were demonstrated to be optimal for the production of P. ostreatus mushrooms and bioethanol fuel. After solid state fermentation, the chitin-protein structure and calcium carbonate in shell waste were depolymerized and degraded and resulting in 24.53% higher than the initial substrate in enzymatic digestibility with chitinase. The highest total theoretical yield of ethanol was 7.72 ml/100 g and N-acetylglucosamine contributes 66.63%. This strategy could help divert excess nutrients in chitin waste biomass away from the environment into protein-rich oyster mushroom food and green biofuels production.