Saccharification of lignocellulosic biomass using an enzymatic cocktail of fungal origin and successive production of butanol by Clostridium acetobutylicum

A multistep approach was undertaken for biobutanol production targeting valorization of agricultural waste. Optimum production of lignocellulolytic enzymes [CMCase (3822.93U/mg), FPase (3640.93U/mg), beta-glucosidase (3873.92U/mg), xylanase (3460.24U/mg), pectinase (3359.57U/mg), alpha-amylase (4136.54U/mg), and laccase (3863.16U/rag)] was accomplished through solid-substrate fermentation of pretreated mixed substrates (wheat bran, sugarcane bagasse and orange peel) by Aspergillus roger SKN1 and Trametes hirsuta SKH1. Partially purified enzyme cocktail was employed for saccharification of the said substrate mixture into fermentable sugar (69.23 g/L, product yield of 24% w/w). The recovered sugar with vegetable extract supplements was found as robust fermentable medium that supported 16.51 g/L biobutanol production by Clostridium acetobutylicum ATCC824. The sequential bioprocessing of low-priced substrates and exploitation of vegetable extract as growth factor for microbial butanol production will open a new vista in biofuel research.