a Department of Microbiology, Laboratory of Enzyme Technology and Protein Bioinformatics , Maharshi Dayanand University , Rohtak , India.
b Division of Microbiology , Indian Agricultural Research Institute , New Delhi , India.
Crit Rev Microbiol. 2018 Mar;44(2):244-257. doi: 10.1080/1040841X.2017.1337713. Epub 2017 Jun 13.
Second generation biofuel production has been appeared as a sustainable and alternative energy option. The ultimate aim is the development of an industrially feasible and economic conversion process of lignocellulosic biomass into biofuel molecules. Since, cellulose is the most abundant biopolymer and also represented as the photosynthetically fixed form of carbon, the efficient hydrolysis of cellulose is the most important step towards the development of a sustainable biofuel production process. The enzymatic hydrolysis of cellulose by suites of hydrolytic enzymes underlines the importance of cellulase enzyme system in whole hydrolysis process. However, the selection of the suitable cellulolytic enzymes with enhanced activities remains a challenge for the biorefinery industry to obtain efficient enzymatic hydrolysis of biomass. The present review focuses on deciphering the novel and effective cellulases from different environmental niches by unculturable metagenomic approaches. Furthermore, a comprehensive functional aspect of cellulases is also presented and evaluated by assessing the structural and catalytic properties as well as sequence identities and expression patterns. This review summarizes the recent development in metagenomics based approaches for identifying and exploring novel cellulases which open new avenues for their successful application in biorefineries.
第二代生物燃料的生产已经成为一种可持续和替代能源的选择。最终目标是开发一种工业上可行且经济的转化工艺，将木质纤维素生物质转化为生物燃料分子。由于纤维素是最丰富的生物聚合物，也是光合作用固定碳的形式，因此纤维素的高效水解是开发可持续生物燃料生产工艺的最重要步骤。纤维素在水解酶的协同作用下的酶解强调了纤维素酶酶系统在整个水解过程中的重要性。然而，选择具有增强活性的合适的纤维素酶仍然是生物炼制工业面临的挑战，以获得有效的生物质酶解。本综述重点通过不可培养的宏基因组学方法，从不同的环境小生境中揭示新型有效的纤维素酶。此外，还通过评估结构和催化特性以及序列同一性和表达模式，对纤维素酶的综合功能方面进行了介绍和评估。本综述总结了基于宏基因组学的方法在鉴定和探索新型纤维素酶方面的最新进展，为它们在生物炼制中的成功应用开辟了新的途径。
