Immobilized Biocatalysts in Bioethanol Production: Scale-up Opportunities for Commercialization

Abstract

Bioethanol is a form of renewable energy produced from carbohydrate-rich feedstocks. Bioethanol can be generated from universally available crops like hemp, sugarcane, cassava, corn, wheat crops, waste straw, sawdust, etc. It is mostly used as a motor fuel, an additive for gasoline. The blending of bioethanol with petrol helps in overcoming the problems of declining oil supply due to diminishing fossil fuels. Lignocellulosic materials are converted into fermentable sugars by saccharification using cellulase enzyme. The use of free cellulase leads to the loss of enzyme and makes the process expensive. The use of immobilized enzyme is an effective way to obtain stable and reusable enzymes with resistance to different environmental parameters. Immobilization cellulase on nanoparticles improves enzymatic activity due to the synergistic effect of cellulose with certain nanomaterials and enhances stability, reusability, increase in catalytic properties, and limitation of microbial growth. Further liberated glucose can be converted to ethanol by fermentation using free or immobilized yeast cells. The use lignocellulosic materials for bioethanol production will help to reduce the urban waste disposal problem and meet the energy demand in the near future. Thus, the immobilization strategy could improve the bioethanol production economically and commercialized for enhanced bioethanol production.