 The review discusses how acidic thermochemical pre-treatment of lignocellulose feedstocks can inhibit enzymatic hydrolysis and microbial fermentation, and presents methods to alleviate these problems through conditioning of slurries and hydrolysates, as well as novel developments in chemical detoxification and biocatalyst performance improvement. This article was authored by Johnson-Leaf J, Aurex and Buon, and Neil Vibrant-Neil-Zollough.