Pilot scale conversion of wheat straw to ethanol via simultaneous saccharification and fermentation

•Conversion of wheat straw to ethanol was scaled up at pilot scale.•Dilute acid pretreated wheat straw was bioabated by growing a fungus aerobically.•Recombinant bacterium fermented all sugars to ethanol.•Maximum ethanol produced from 124 g wheat straw was 36 g in 83 h.•Ethanol yield was 0.29 g/g wheat straw which is 86% of theoretical ethanol yield.

The production of ethanol from wheat straw (WS) by dilute acid pretreatment, bioabatement of fermentation inhibitors by a fungal strain, and simultaneous saccharification and fermentation (SSF) of the bio-abated WS to ethanol using an ethanologenic recombinant bacterium was studied at a pilot scale without sterilization. WS (124.2 g/L) was pretreated with dilute H2SO4 in two parallel tube reactors at 160 °C. The inhibitors were bio-abated by growing the fungus aerobically. The maximum ethanol produced by SSF of the bio-abated WS by the recombinant Escherichia coli FBR5 at pH 6.0 and 35 °C was 36.0 g/L in 83 h with a productivity of 0.43 g L−1 h−1. This value corresponds to an ethanol yield of 0.29 g/g of WS which is 86% of the theoretical ethanol yield from WS. This is the first report on the production of ethanol by the recombinant bacterium from a lignocellulosic biomass at a pilot scale.