Abstract: A method of producing a modified Saccharomyces cerevisiae yeast strain with enhanced resistance (or tolerance) to pretreatment-derived microbial inhibitors such as furans, phenolics and weak acids is provided, which comprises integrating at least one copy of the TAL1 gene and at least one copy of two or more of the FDH1, AR11 and ADH6 genes into the S. cerevisiae genome. A modified yeast strain so obtained is also provided, the modified yeast strain being capable of simultaneously overexpressing these genes relative to a yeast strain which hasn't been modified in the same manner. S. cerevisiae strains which have been modified as described herein can be used to ferment lignocellulosic hydrolysates containing pretreatment inhibitors such as furans, phenolics and weak acids. Suitable lignocellulosic hydrolysates include sugarcane bagasse (SCB) and waste streams from the pulp and paper industry, such as spent sulphite liquor (SSL).