Grasses are considered to be potential lignocellulosic feedstock for renewable and sustainable biofuels such as bioethanol. However, the process involved, ie, pretreatment, enzymatic saccharification, and fermentation in conversion of these lignocellulosic biomass to bioethanol, remains expensive and at present is not affordable for industrial production. Thus, the present review assesses the influence of the recent technologies that can be employed for the bio-refinery based pretreatment and enzymatic hydrolysis of grass biomass using advanced bioreactors. Since plant extracts have been seen to enhance the glucose uptake, an experiment was implemented to elucidate the role of plant extracts (bark extracts of Xylocarpus granatum) on glucose uptake capacity of microorganisms like Saccharomyces cerevisiae, Pichia sp., and Zymomonas mobilis and their subsequent ethanol production capability from glucose and xylose sugars. The results of these experiments indicated that supplementation of plant extracts promoted both glucose and xylose uptake in S. cerevisiae and Pichia sp. as compared with the control and Z. mobilis strain. Further, as Pichia sp. exhibited good uptake ability for both glucose and xylose, a model was proposed focusing on the gene silencing and operon concept in Pichia sp. for preferential pentose utilization during the fermentation of grass biomass to bioethanol.