We explored the application of Low-Intensity Pulsed Ultrasound (LIPUS) technology to improve the metabolic activity of microorganisms. In this study we showed that LIPUS improves bio-ethanol production from lignocellulosic biomass. We determined specific LIPUS conditions to increase the metabolic activity of both the cellulose degrading fungus, Trichoderma reesei Rut C-30 and the ethanol producing yeast, Saccharomyces cerevisiae. LIPUS conditions of 1.5 MHz, 20% duty cycle, 80 mW/cm(2) intensity, 5 min exposure and 12 exposures per day were found to improve the activity of the organisms the most. These LIPUS treatment conditions increased cellulase production by T reesei by 16 +/- 6%. The same LIPUS treatment conditions induced a 31 +/- 10% increase in ethanol production by S. cerevisiae which implies a cumulative improvement of 52 +/- 16% in lignocellulosic bio-ethanol production with LIPUS. This observation shows a new potential for LIPUS in the improvement of lignocellulosic bioethanol production to make it a sustainable energy source. (C) 2013 Elsevier Ltd. All rights reserved.