Application of low-intensity pulsed ultrasound to increase bio-ethanol production

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/cm2 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.

► Low-intensity pulsed ultrasound (LIPUS) stimulates the microorganisms.
► Specific LIPUS parameters increase cellulase production by Trichoderma reesei.
► Specific LIPUS parameters increase ethanol production by Saccharomyces cerevisiae.
► Thus LIPUS has a potential to increase lignocellulosic bioethanol production.