The article discusses how using ultrasound with enzymes can speed up the process of making biodiesel. Biodiesel is a cleaner fuel made from vegetable oils or animal fats. Enzymes help make biodiesel in a more eco-friendly way, but they can be slow. By adding ultrasound, the reaction time can be reduced, making the process faster and more efficient. This method is better for the environment and produces biodiesel with high purity.