Xiros Charilaos, Topakas Evangelos, Katapodis Petros, Christakopoulos Paul
Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Strasse, Zografou Campus, 15700 Athens, Greece.
Bioresour Technol. 2008 Sep;99(13):5427-35. doi: 10.1016/j.biortech.2007.11.010. Epub 2008 Feb 21.
In this study, the ethanol production by the mesophilic fungus Neurospora crassa from BG was studied and optimized concerning the induction of lignocellulose degrading enzymes and the production phase as well. The production of cellulolytic and hemicellulolytic enzymes was studied under solid-state cultivation (SSC). SSC in a laboratory horizontal bioreactor using the optimized medium, WS and BG in the ratio 1:1 and initial moisture level 61.5%, allowed the large scale production of the multienzymatic system. Similar yields with those from flasks experiments, as high as 1073,56,4.2,1.6,3.1,5.7 and 0.52 U g(-1) carbon source of xylanase, endoglucanase, cellobiohydrolase, beta-glucosidase, alpha-l-arabinofuranosidase, acetyl esterase and feruloyl esterase, respectively, were obtained. Chromogenic (fluorogenic) 4-methylumbelliferyl substrates were used to characterize the major activities of the multienzyme component, after the separation by isoelectric focusing (IEF) electrophoresis. Alkali pre-treated BG was used for ethanol production. A yield of about 74 g of ethanol kg(-1) dry BG (5,6 g L(-1)) was obtained under optimum conditions (aeration 0.1 vvm, pre-treatment with 1g NaOH 10 g(-1)dry BG).
在本研究中，对嗜温真菌粗糙脉孢菌利用桦木聚糖生产乙醇的过程进行了研究，并针对木质纤维素降解酶的诱导以及生产阶段进行了优化。在固态培养（SSC）条件下研究了纤维素分解酶和半纤维素分解酶的产生。在实验室水平生物反应器中采用优化培养基进行固态培养，木糖渣（WS）和桦木聚糖（BG）比例为1:1，初始水分含量为61.5%，可实现多酶系统的大规模生产。获得了与摇瓶实验相似的产量，木聚糖酶、内切葡聚糖酶、纤维二糖水解酶、β-葡萄糖苷酶、α-L-阿拉伯呋喃糖苷酶、乙酰酯酶和阿魏酸酯酶的产量分别高达1073、56、4.2、1.6、3.1、5.7和0.52 U g(-1)碳源。在通过等电聚焦（IEF）电泳分离后，使用显色（荧光）4-甲基伞形酮底物来表征多酶组分的主要活性。经碱预处理的桦木聚糖用于乙醇生产。在最佳条件下（通气量0.1 vvm，用1 g NaOH对10 g(-1)干桦木聚糖进行预处理），乙醇产量约为74 g乙醇 kg(-1)干桦木聚糖（5.6 g L(-1)）。
