Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece.
Appl Microbiol Biotechnol. 2013 Feb;97(4):1457-73. doi: 10.1007/s00253-012-4655-2. Epub 2013 Jan 15.
Microbial production of ethanol might be a potential route to replace oil and chemical feedstocks. Bioethanol is by far the most common biofuel in use worldwide. Lignocellulosic biomass is the most promising renewable resource for fuel bioethanol production. Bioconversion of lignocellulosics to ethanol consists of four major unit operations: pretreatment, hydrolysis, fermentation, and product separation/distillation. Conventional bioethanol processes for lignocellulosics apply commercial fungal cellulase enzymes for biomass hydrolysis, followed by yeast fermentation of resulting glucose to ethanol. The fungus Neurospora crassa has been used extensively for genetic, biochemical, and molecular studies as a model organism. However, the strain's potential in biotechnological applications has not been widely investigated and discussed. The fungus N. crassa has the ability to synthesize and secrete all three enzyme types involved in cellulose hydrolysis as well as various enzymes for hemicellulose degradation. In addition, N. crassa has been reported to convert to ethanol hexose and pentose sugars, cellulose polymers, and agro-industrial residues. The combination of these characteristics makes N. crassa a promising alternative candidate for biotechnological production of ethanol from renewable resources. This review consists of an overview of the ethanol process from lignocellulosic biomass, followed by cellulases and hemicellulases production, ethanol fermentations of sugars and lignocellulosics, and industrial application potential of N. crassa.
微生物生产乙醇可能是替代石油和化学原料的潜在途径。生物乙醇是目前全球应用最广泛的生物燃料。木质纤维素生物质是最有前途的可再生燃料乙醇生产资源。木质纤维素生物转化为乙醇包括四个主要单元操作：预处理、水解、发酵和产物分离/蒸馏。用于木质纤维素的常规生物乙醇工艺应用商业真菌纤维素酶进行生物质水解，然后酵母发酵生成的葡萄糖生产乙醇。真菌粗糙脉孢菌（Neurospora crassa）被广泛用于遗传、生化和分子研究，作为一种模式生物。然而，该菌株在生物技术应用中的潜力尚未得到广泛的研究和讨论。粗糙脉孢菌能够合成和分泌纤维素水解所涉及的三种酶以及各种半纤维素降解酶。此外，已有报道称粗糙脉孢菌能够将己糖和戊糖、纤维素聚合物和农业工业残留物转化为乙醇。这些特性的结合使粗糙脉孢菌成为从可再生资源中生物技术生产乙醇的有前途的替代候选物。本文综述了从木质纤维素生物质生产乙醇的过程，包括纤维素酶和半纤维素酶的生产、糖和木质纤维素的乙醇发酵以及粗糙脉孢菌的工业应用潜力。
