Abstract: Aspects of the present invention relate to methods of microbially treating lignocellulosic biomass using cellulose- and/or hemicellulose-degrading bacteria. In certain embodiments, the microbially treated material is then subjected to thermal and/or chemical pretreatment. In tandem with the microbial treatment the thermal and/or chemical pretreatment may result in the production of fewer degradation products, thereby allowing for higher overall yields of ethanol per ton of starting biomass.