Oxidation of lignans and lignin model compounds by laccase in aqueous solvent systems
Oxidation of lignans and lignin model compounds by laccase in aqueous solvent systems
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DOI：
10.1016/j.molcatb.2011.05.009
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发表时间：
2011-11-01
影响因子：
--
通讯作者：
Viikari, Liisa
中科院分区：
文献类型：
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作者：
Mattinen, Maija-Liisa;Maijala, Pekka;Viikari, Liisa
以2，6-二甲氧基苯酚（2，6-dichloroethanol，2，6-dichloroethanol，2，6-dichloroethanol）为底物，采用比色法研究了低氧化还原电位白黑果漆酶（Melanocarpusalbomarpuslaccase，MaL）在不同有机溶剂（丙酮、乙醇、丙二醇、二甘醇单甲醚）中的稳定性和活性。此外，酶与两个木脂素的反应性; matairesinol（MR）和7-hydroxymatairesinol（HMR），在最有潜力的含水有机溶剂系统中的氧消耗测量检查。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和尺寸排阻色谱（SEC）验证MaL对木脂素的聚合。用SEC法研究了高分子量木质素模型化合物脱氢聚合物（DHPs）的聚合。工业针叶木和阔叶木硫酸盐木质素的溶解度进行了评估，作为参数的研究在水有机溶剂体系中的酶改性。MaL在不同的有机水溶液中均表现出良好的功能。丙二醇和二甘醇单甲醚是较好的酶促氧化溶剂，而乙醇和丙酮则是较好的溶剂。尽管乙醇和丙二醇是酶氧化的最佳溶剂，但由于其不同的理化性质，它们被选择用于进一步的测试。在本研究中获得的结果，在有机溶剂中使用漆酶催化的反应，以提高木质素氧化的效率，可以利用在几个应用和领域中的反应物或产物的溶解度是一个限制因素。(C)2011爱思唯尔有限公司版权所有。
The stability and activity of the low redox potential Melanocarpus albomyces laccase (MaL) in various aqueous organic (acetone, ethanol, propylene glycol, diethylene glycol monomethyl ether) solvent systems was studied spectrophotometrically using 2,6-dimethoxyphenol (2,6-DMP) as substrate. In addition, reactivity of the enzyme with two lignans; matairesinol (MR) and 7-hydroxymatairesinol (HMR), was examined by oxygen consumption measurements in the most potential aqueous organic solvent systems. Polymerization of the lignans by MaL was verified by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and size exclusion chromatography (SEC). Polymerization of the higher molecular weight lignin model compound, dehydrogenation polymers (DHPs), was studied by SEC. The solubilities of industrial softwood and hardwood kraft lignins were evaluated as parameters for investigation of enzymatic modification in aqueous organic solvent systems. The functioning of MaL in different aqueous organic media was excellent. Propylene glycol and diethylene glycol monomethyl ether were better solvents than ethanol or acetone in enzymatic oxidations. Even though they were the best solvents for enzyme oxidation, ethanol and propylene glycol were selected for further tests because of their different physicochemical properties. The results obtained in this study for the use of laccase-catalysed reactions in organic solvents to improve the efficiency of lignin oxidation may be exploited in several applications and areas in which the solubility of the reactants or products is a limiting factor. (C) 2011 Elsevier B.V. All rights reserved.