Nair Lakshana G, Agrawal Komal, Verma Pradeep
Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, Kishangarh, Ajmer, India.
Biotechnol Genet Eng Rev. 2022 Oct;38(2):288-338. doi: 10.1080/02648725.2022.2082223. Epub 2022 Jun 7.
Lignocellulosic biomass (LCB) is an energy source that has a huge impact in today's world. The depletion of fossil fuels, increased pollution, climatic changes, etc. have led the public and private sectors to move towards sustainability i.e. using LCB for the production of biofuels and value-added compounds. A major bottleneck of the process is the recalcitrant nature of LCB. This can be overcome by using various pretreatment strategies like physical, chemical, biological, physicochemical, etc. Further, the pretreated biomass is made to undergo various steps like hydrolysis, saccharification, etc. for the conversion of value-added products and the remaining waste residues can be further utilized for the synthesis of secondary products thus favouring the zero-waste biorefinery concept. Currently, microorganisms are being explored for their use in biorefinery but the unavailability of commercial strains is a major limitation. Thus, the use of metagenomics can be used to overcome the limitation which is both cost-effective and environmentally friendly. The review deliberates the composition of LCBs, and their recalcitrance nature, followed by the structural changes caused by various pretreatment methods. The further steps in biorefineries, strategies for the development of zero-waste refineries, bottlenecks, and suggestions are also discussed. Special emphasis is given to the use of metagenomics for the discovery of microorganisms efficient for zero-waste biorefineries.
木质纤维素生物质（LCB）是一种在当今世界具有巨大影响的能源。化石燃料的枯竭、污染加剧、气候变化等因素促使公共和私营部门朝着可持续发展方向迈进，即利用LCB生产生物燃料和增值化合物。该过程的一个主要瓶颈是LCB的顽固性质。这可以通过使用各种预处理策略来克服，如物理、化学、生物、物理化学等方法。此外，预处理后的生物质要经过水解、糖化等各种步骤来转化增值产品，剩余的废渣可以进一步用于合成二次产品，从而有利于零废物生物精炼概念。目前，正在探索微生物在生物精炼中的应用，但商业菌株的缺乏是一个主要限制。因此，宏基因组学的应用可以用来克服这一限制，它既经济又环保。本文综述了LCB的组成及其顽固性质，接着阐述了各种预处理方法引起的结构变化。还讨论了生物精炼中的后续步骤、零废物精炼厂的发展策略、瓶颈问题及建议。特别强调了利用宏基因组学发现对零废物生物精炼有效的微生物。
