Saccharification with Phanerochaete chrysosporium and Pleurotus ostreatus enzymatic extracts of pretreated banana waste

摘要

Lignocellulosic biomass has a great potential as raw material for second and third generation biofuels since it is the most abundant carbohydrate on earth and the main component of agricultural waste; however, saccharification of lignocellulosic biomass is crucial for the establishment of a carbohydrate-based economy. The use of fungal enzymes is the preferred procedure for lignocellulosic saccharification. Fungi such as basidiomycetes (e.g?Phanerochaete chrysosporium) produce cellulolytic/hemicellulolytic and ligninolytic enzymes, which are responsible for lignocellulose degradation. In this study the saccharification of banana flour prepared from pseudostem and green non commercial-grade fruit (1:1), two of the main agro-waste of banana industry was investigated. The material was pretreated by physical and chemical processes including drying and grinding, followed by 3% HCl or 3% NaOH hydrolysis, or a sequential pretreatment with 3% HCl first and then 3% NaOH and heated at 121°C, at 15 Lb/in2?for 15 min. The highest concentration of reducing sugars (RS) was obtained with acid hydrolysis (42.41 gL-1). Crude cellulolytic-ligninolytic enzymatic extracts from?Pleurotus ostreatus?and?P. chrysosporium?cultured on banana waste as the only carbon source were prepared and used for the saccharification. Surprisingly,?P. chrysosporium?crude extract produced a decrease in RS (2.27 gL-1). Although?P. ostreatus?cellulose activity (17,777.78 UL-1) was almost half compared to?P. chrysosporium’s (31,296.30 UL-1), the former produced an increment in the release of RS (63.65 gL-1).? In Mexico, banana is one of the main crops and generates large agricultural waste after harvest. According to the results obtained with acid-heat pretreatment followed by saccharification with?P. ostreatus?enzymatic crude extract,?banana agro-waste can be considered as a potential feedstock for RS-based bioproducts like bioethanol.