摘要
漆酶/介体系统(laccase-mediator system,LMS)在木质素生物降解及其资源化利用领域具有巨大的潜在应用价值,但LMS仍存在介体重复利用率低、电子供体不足等问题.电子传递性能优异的碳基材料石墨烯具有解决这些问题的潜力,本文研究了石墨烯对漆酶-ABTS系统降解碱木素的影响.结果表明,石墨烯促进了漆酶-ABTS系统对碱木素的降解,使碱木素的降解率在10 h内提高了28%.石墨烯的添加使得漆酶-ABTS系统对氧的消耗速率加快了4倍.碱木素的FTIR与XPS结果表明,石墨烯的添加强化了漆酶-ABTS系统对碱木素的降解.石墨烯反应前后并没有明显变化,循环伏安结果表明,石墨烯作为"电子导体"提高了ABTS中间体与碱木素之间的电子传递效率,促进了ABTS+·向ABTS2+的转化,提高了ABTS2+氧化碱木素中非酚类结构单元的速率.石墨烯的添加使得ABTS+·稳态浓度处于较高的水平,提高了介体重复利用率.本研究证明了碳基材料石墨烯作为"电子导体"强化了漆酶-ABTS系统对碱木素的催化降解,为木质素生物降解及其资源化利用提供了新的方法和思路.
Laccase-mediator system（ LMS） is promising for the biodegradation and utilization of lignin. However,there are still some problems to be solved in the LMS,such as poor reusability of mediators and insufficient supply of exogenous electron donors. Graphene with excellent electron transfer performance has the potential to solve these problems. Here we investigated the effects of graphene on the degradation of alkali lignin by laccase-ABTS system. After adding graphene,the degradation rate of alkali lignin increased by 28% in 10 h and the observed rate of oxygen consumption was accelerated by about 4 times. In addition,FTIR and XPS analyses of alkali lignin also showed that the degradation efficiency of alkali lignin in the laccase-ABTS system was greatly enhanced in the presence of graphene. As revealed by the combined spectroscopic analyses,graphene was neither oxidized nor reduced after the reaction. Cyclic voltammetry results imply that the graphene may serve as the conductor transferring the electron from alkali lignin to ABTS^2＋ whichhas a much greater reactivity towards nonphenolic structural units of alkali lignin. And the presence of graphene resulted in a relatively high yield of AB TS^＋·,which effectively improved the ratio of mediator recycle. This study indicates that graphene may act as a conductor to enhance the degradation efficiency of alkali lignin in the laccase-ABTS system,which could eventually lead to the development of novel ideas and methods for the biodegradation and utilization of lignin.
作者
黄丽萍
马华
潘雨
黄紫薇
黄娟
刘艳
HUANG Liping;MA Hua;PAN Yu;HUANG Ziwei;HUANG Juan;LIU Yan(Key Laboratory of Three Gorges Reservoir Region＇s Eeo-Environment,Ministry of Education, Chongqing University, Chongqing, 400045, Chin)
出处
《环境化学》
CAS
CSCD
北大核心
2018年第4期704-712,共9页
Environmental Chemistry
基金
国家自然科学基金(2140715)
中央高校基本科研业务费科研专项(106112016CDJXY210001,106112017CDJQJ218845)资助
