a Department of Biotechnology , Engineering School of Lorena, University of São Paulo , Lorena , Sao Paulo , Brazil and.
Crit Rev Biotechnol. 2015;35(3):281-93. doi: 10.3109/07388551.2013.841638.
Lignocellulosic biomass (LB) is a promising sugar feedstock for biofuels and other high-value chemical commodities. The recalcitrance of LB, however, impedes carbohydrate accessibility and its conversion into commercially significant products. Two important factors for the overall economization of biofuel production is LB pretreatment to liberate fermentable sugars followed by conversion into ethanol. Sustainable biofuel production must overcome issues such as minimizing water and energy usage, reducing chemical usage and process intensification. Amongst available pretreatment methods, microorganism-mediated pretreatments are the safest, green, and sustainable. Native biodelignifying agents such as Phanerochaete chrysosporium, Pycnoporous cinnabarinus, Ceriporiopsis subvermispora and Cyathus stercoreus can remove lignin, making the remaining substrates amenable for saccharification. The development of a robust, integrated bioprocessing (IBP) approach for economic ethanol production would incorporate all essential steps including pretreatment, cellulase production, enzyme hydrolysis and fermentation of the released sugars into ethanol. IBP represents an inexpensive, environmentally friendly, low energy and low capital approach for second-generation ethanol production. This paper reviews the advancements in microbial-assisted pretreatment for the delignification of lignocellulosic substrates, system metabolic engineering for biorefineries and highlights the possibilities of process integration for sustainable and economic ethanol production.
木质纤维素生物质（LB）是生物燃料和其他高价值化工产品的有前途的糖原料。然而，LB 的顽固性阻碍了碳水化合物的可及性及其转化为具有商业意义的产品。生物燃料生产的整体经济化的两个重要因素是 LB 预处理以释放可发酵糖，然后转化为乙醇。可持续生物燃料生产必须克服一些问题，如最大限度地减少水和能源的使用、减少化学物质的使用和工艺强化。在可用的预处理方法中，微生物介导的预处理是最安全、绿色和可持续的。天然生物脱木质素剂，如黄孢原毛平革菌、红栓菌、绒盖牛肝菌和嗜热侧孢霉，可以去除木质素，使剩余的底物易于糖化。开发一种强大的、综合的生物加工（IBP）方法来经济地生产乙醇，将包括所有必要的步骤，包括预处理、纤维素酶生产、酶解和释放的糖发酵成乙醇。IBP 代表了一种廉价、环保、低能耗和低资本的第二代乙醇生产方法。本文综述了微生物辅助预处理木质纤维素底物脱木质素、生物炼制系统代谢工程的进展，并强调了工艺集成的可能性，以实现可持续和经济的乙醇生产。
