Document Type : Review Paper
Department of Biotechnology, Punjabi University, Patiala-147002, Punjab, India.
Faculty of Applied Medical Sciences, Lovely Professional University, Phagwara-144411, Punjab, India.
School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India.
Biochemical Conversion Division, Sardar Swaran Singh National Institute of Bio-Energy, Kapurthala-144601, India.
Department of Biotechnology, Engineering School of Lorena (EEL), University of São Paulo, Lorena-SP- 12606452, Brazil.
Many countries have their biofuel policy programs in place as part of their overall strategy to achieve sustainable development. Among biofuels, bioethanol as a promising alternative to gasoline is of substantial interest. However, there is limited availability of a sufficient quantity of bioethanol to meet demands due to bottlenecks in the present technologies to convert non-edible feedstocks, including lignocelluloses. This review article presents and critically discusses the recent advances in the pretreatment of lignocellulosic biomass, with a focus on the use of green solvents, including ionic liquids and deep eutectic solvents, followed by enzymatic saccharification using auxiliary proteins for the efficient saccharification of pretreated biomass. Different techniques used in strain improvement strategies to develop hyper-producing deregulated lignocellulolytic strains are also compared and discussed. The advanced techniques employed for fermentation of mixed sugars contained in lignocellulosic hydrolysates for maximizing bioethanol production are summarized with an emphasis on pathway and transporters engineering for xylose assimilation. Further, the integration of different steps is suggested and discussed for efficient biomass utilization and improved ethanol yields and productivity.
- Recent advances in pretreatment of lignocellulosic biomass are reviewed and discussed.
- Use of green solvents, including ionic liquids and deep eutectic solvents, is presented.
- Strain improvement strategies to develop hyper-producing lignocellulolytic strains are compared.
- Advanced techniques for fermentation of mixed sugars in lignocellulosic hydrolysates are presented.
- Integration approaches for efficient biomass utilization and improved ethanol yields and productivity are discussed.