Department of Biotechnology, School of Engineering of Lorena, University of São Paulo, Lorena/SP, Brazil.
Crit Rev Biotechnol. 2012 Sep;32(3):187-202. doi: 10.3109/07388551.2011.595385. Epub 2011 Sep 19.
Geopolitical concerns (unstable supply of gasoline, environmental pollution, and regular price hikes), economic, and employment concerns have been prompting researchers, entrepreneurs, and policy makers to focus on harnessing the potential of lignocellulosic feedstock for fuel ethanol production and its commercialization. The carbohydrate skeleton of plant cell walls needs to be depolymerised into simpler sugars for their application in fermentation reactions as a chief carbon source of suitable ethnologic strains for ethanol production. The role of cellulolytic enzymes in the degradation of structural carbohydrates of the plant cell wall into ready-to-fermentable sugar stream is inevitable. Cellulase synergistically acts upon plant cell wall polysaccharides to release glucose into the liquid media. Cellulase predominantly dominates all the plant cell wall degrading enzymes due to their vast and diverse range of applications. Apart from the major applications of cellulases such as in detergent formulations, textile desizing, and development of monogastric feed for ruminants, their role in biorefinery is truly remarkable. This is a major area where new research tools based upon fermentation based formulations, biochemistry, and system biology to expedite the structure-function relationships of cellulases including cellulosomes and new designer enzymatic cocktails are required. In the last two decades, a considerable amount of research work has been performed on cellulases and their application in biomass saccharification. However, there are still technical and economic impediments to the development of an inexpensive commercial cellulase production process. Advancements in biotechnology such as screening of microorganisms, manipulation of novel cellulase encoding traits, site-specific mutagenesis, and modifications to the fermentation process could enhance the production of cellulases. Commercially, cheaper sources of carbohydrates and modified fermentation conditions could lead to more cost-effective production of cellulases with the goal to reduce the cost of ethanol production from lignocellulosics. Implementation of integrated steps like cellulase production and cellulase mediated saccharification of biomass in conjunction with the fermentation of released sugars in ethanol in a single step so called consolidated bio-processing (CBP) is very important to reduce the cost of bioethanol. This paper aims to explore and review the important findings in cellulase biotechnology and the forward path for new cutting edge opportunities in the success of biorefineries.
地缘政治问题（汽油供应不稳定、环境污染和定期涨价）、经济和就业问题促使研究人员、企业家和政策制定者关注利用木质纤维素原料生产燃料乙醇及其商业化。植物细胞壁的碳水化合物骨架需要解聚成更简单的糖，以便将其作为适合乙醇生产的合适发酵菌株的主要碳源应用于发酵反应中。纤维素酶在将植物细胞壁的结构性碳水化合物降解为可发酵糖流方面发挥着重要作用。纤维素酶协同作用于植物细胞壁多糖，将葡萄糖释放到液体培养基中。由于其广泛而多样的应用，纤维素酶在所有植物细胞壁降解酶中占主导地位。除了纤维素酶在洗涤剂配方、纺织品退浆和反刍动物单胃动物饲料开发等方面的主要应用外，它们在生物炼制中的作用也非常显著。这是一个需要新的研究工具的主要领域，这些工具基于发酵配方、生物化学和系统生物学，以加速纤维素酶（包括纤维小体和新型设计酶鸡尾酒）的结构-功能关系。在过去的二十年中，人们对纤维素酶及其在生物质糖化中的应用进行了大量的研究。然而，开发廉价的商业纤维素酶生产工艺仍然存在技术和经济障碍。生物技术的进步，如微生物的筛选、新型纤维素酶编码特性的操纵、定点突变和发酵过程的修改，可以提高纤维素酶的产量。在商业上，更便宜的碳水化合物来源和改良的发酵条件可以导致更具成本效益的纤维素酶生产，目标是降低从木质纤维素生产乙醇的成本。实施综合步骤，如纤维素酶生产和纤维素介导的生物质糖化，以及在单个步骤中发酵释放的糖以生产乙醇，即所谓的整合生物加工（CBP），对于降低生物乙醇的成本非常重要。本文旨在探讨和综述纤维素酶生物技术的重要发现，以及在生物炼制成功方面新的前沿机遇的前进道路。
