Pretreatment of lignocellulosic biomass using bioleaching to reduce inorganic elements

•Bioleaching was first time studied to remove elements from cellulosic biomass.•Elemental removal efficiency depended on the type of biomass and species of microbes.•Water/biomass ratio of 25 and 0.5 h were enough for bioleaching of sorghum by A. niger.•Acidification appeared to be one of major mechanisms for A. niger bioleaching.