Bioethanol Production by Enzymatic Hydrolysis from Different Lignocellulosic Sources

Abstract

As the need for non-renewable sources such as fossil fuels has increased during the last few decades, the search for sustainable and renewable alternative sources has gained growing interest. Enzymatic hydrolysis in bioethanol production presents an important step, where sugars that are fermented are obtained in the final fermentation process. In the process of enzymatic hydrolysis, more and more new effective enzymes are being researched to ensure a more cost-effective process. There are many different enzyme strategies implemented in hydrolysis protocols, where different lignocellulosic biomass, such as wood feedstocks, different agricultural wastes, and marine algae are being used as substrates for an efficient bioethanol production. This review investigates the very recent enzymatic hydrolysis pathways in bioethanol production from lignocellulosic biomass.

Hydrothermal Liquefaction of Biomass as One of the Most Promising Alternatives for the Synthesis of Advanced Liquid Biofuels: A Review

“…Bioethanol: This is the most widely used biofuel. It is obtained through the hydrolysis of cellulose present in lignocellulosic biomass (such as wood, straw, or grass) and the fermentation of sugars [ 30 ]. This process occurs in two steps.…”

Conversion of Lignocellulose for Bioethanol Production, Applied in Bio-Polyethylene Terephthalate

“…The complex polymer of lignocellulose can be converted from polysaccharides into fermentable sugars. A variety of pretreatment procedures are available [ 31 ]. Figure 3 relates to the schematic hydrolysis of lignocellulose to ethanol formation.…”

“…The depolymerization of cellulose into glucose can be conducted by enzymatic hydrolysis. The enzymatic hydrolysis is operated under mild conditions; for instance, the range temperature and pH are 40–50 °C and 4.5–5, respectively [ 31 ]. The cellulose hydrolysis process can be broken up into two basic enzymatic schemes, multi-enzymes, bacteria, and fungi applied the free extracellular enzymes.…”

Saccharification and Fermentation of Cellulolytic Agricultural Biomass to Bioethanol using Locally Isolated Aspergillus niger S48 and Kluyveromyces sp. Y2, respectively

“…The fermentation of the sugars obtained from the hydrolysis to ethanol is the final step of the process [7,8] For efficient bioethanol production using lignocellulosic plant biomass, the enzymes engaged for hydrolysis must adsorb to the biomass surface before the breaking down of the biomass will take place [8]. According to Vasić et al [11], the breaking down of the pre-treated biomass using enzymes in the production of bioethanol is an essential step that will give rise to fermentable sugars. There has been non-stop search into finding more effective enzymes that will guarantee a cheaper production cost [11].…”