Biotechnological advances in lignocellulosic ethanol production

Abstract

The worldwide increasing environmental issues owing to fossil fuels and their anticipated shortage in near future have fueled the research towards the search and development of alternative fuels from renewable sources. Recently, the biomass-based transport fuels have turn out to be strategic attention for counties with intention to enhance the sustainability in the terms of bioenergy. Interestingly, bioethanol is an oxygenated biofuel with 35% oxygen content, which can decrease the particulate matter and NOx emissions produced from fuel combustion. Therefore, gasoline blended with bioethanol can considerably decrease the petroleum consumption along with greenhouse gases emission. Though nearly all the present biofuel ethanol is produced from edible materials like sugars, starch etc., the lignocellulosic biomass has received considerable interest in recent years. Nevertheless, the transformation efficiency and ethanol yield of the biomass varies significantly mainly owing to the difference in lignocellulosic content. In lignocellulosic biomass, the complex lignocellulosic network of cellulose and hemicellulose with lignin is extremely resistant towards depolymerization. Thus, there still remain some obstacles that are to be addressed to make lignocellulosic biomass-based bioethanol a commercial reality. Further, the unmet need of cost reduction of lignocellulosic biomass-based bioethanol is progressing towards techno-economic improvements of overall transformation process through efficient biomass pretreatment process as well as recombinant genetic engineering for the microbial strain improvement. Overall, this chapter not only focuses on the current exploitation of different biomasses as substrates but also the biotechnological advances in various bioprocesses leading to improved bioethanol production.