金针菇降解木质素的能力及相关酶活研究

通过对10个金针菇菌株研究发现,在液体培养下不同菌株降解木质素的能力有较大差异,其中金针菇J89-6具有一定的降解木质素的能力,降解率达46%.本文还测定了不同菌株的漆酶、木质素过氧化物酶和锰过氧化物酶三种木质素降解酶的酶活,结果显示漆酶的产量与木质素降解率呈正相关关系.     

蜜环菌胞外漆酶酶活力的分光光度法测定

采用分光光度法测定密环菌（Armillaria mellea）胞外漆酶（Laccase）的活力,分别以2,2′－连氮－二（3－乙基苯并噻唑－6－磺酸）（简称ABTS）、丁香醛连氮、愈创木酚和邻联甲安为底物,比较了这4种底物对漆酸的敏感性,探讨了酶反应时间、温度、缓冲液及其pH值和底物与酶的用量等条件对漆酶催化反应的影响,实验结果表明,适宜的测酶条件可以确保漆酶活力的测定快速而准确。     

白地霉产漆酶条件优化及对偶氮染料脱色研究

对白地霉M3发酵产漆酶进行了研究。在培养的第四天,漆酶的活力达到最高。通过单因素和正交试验对产漆酶培养基优化进行了研究,结果表明葡萄糖、氯化铵为产漆酶最佳碳源和氮源,优化培养基成分为葡萄糖2g/L,硝酸铵1.5g/L,愈创木酚0.015mmol/L,硫酸铜0.06 mmol/L。5L机械搅拌发酵罐和7L气升发酵罐试验中,酶活力分别达到1428U/L、2216U/L,相比机械搅拌发酵罐气升发酵罐更适合白地霉M3产漆酶。粗酶液处理偶氮染料,反应1.5小时后,脱色率达到90.2%,脱色过程进行可见-紫外光谱扫描研究,表明粗酶能降解偶氮染料。     

Biodegradation of methylene blue and carbaryl by Trametes versicolor laccase preparations in the presence of a mediator compound

Laccase from Trametes versicolar was immobilized on to acrylate based microbeads carrying epoxy or carbonate groups. The amounts of immobilized enzyme on the carbonate and epoxy groups were 24.6 and 9.7?mg/g, respectively. In the presence of a mediator (i.e., acetosyringone) almost 100% biodegradation was observed for both Methylene Blue dye (MB) and Carbaryl pesticide (CP) by the immobilized laccases, while in the absence of mediator, 63 and 71%, respectively. The immobilized enzyme was operated in a fluidized bed reactor for biodegradation of MB and CP for 24?h, and the initial activity lost was only 8.0 and 2.0%, respectively. The data show that the immobilized enzyme can effectively be utilized for complete degradation of organic pollutants in wastewaters.     

Catalysis of novel enzymatic iodide oxidation by fungal laccase

A fungal laccase (Myceliophthom thermophila) has been shown to function as an iodide oxidase. Unlike other halides which interact with the type 2 copper site and are inhibitors for the laccase, iodide interacts with the type 1 copper site and serves as a substrate capable of donating an electron to the laccase. Under anaerobic conditions, the interaction between the laccase and iodide results in the reduction of the laccase type 1 copper and the concomitant oxidation of iodide to form iodide. In aerated solutions, the laccase catalyzes the oxidation of iodide to iodine and the concomitant reduction of dioxygen to water. The reaction exhibits typical Michaelis kinetics with aK _m of 0.16 ± 0.02M and ak _cat of 2.7 ± 0.2 turnovers per min at the optimal pH (3.4). The catalysis can be enhanced by 2,2′-azino-bis-(3-ethylbenz-thiazoline-6-sulfonic acid), which shuttles electrons rapidly between iodide and the laccase. Bilirubin oxidase also demonstrates significant iodide oxidase activity, suggesting that the property could be a common feature for copper-containing oxidases. Possible industrial and medicinal applications for a laccase-based iodine production system are discussed.     

不同培养料对鸡腿菇胞外酶活性影响的研究

实验设计了6个不同鸡腿菇培养基配方,分别提取其在菌丝半袋、菌丝满袋、原基、幼菇、成熟5个生长阶段粗酶液,通过测定纤维素酶、漆酶和淀粉酶活性,初步揭示出不同培养基对鸡腿菇纤维素酶、漆酶、淀粉酶活力的影响及规律．结果表明：不同培养基配方对各种酶的活力大小有影响,但各种酶活性在不同基质中变化规律一致,基质成分对酶活性的变化规律无影响．     

Effects of Treating with Laccase on Properties of Dyed Cotton Fabric

A laccase （Denilite IIS） was used to treat different cotton fabrics dyed with 0.2 g · L^-1 of vat dyes or reactive dyes. The results indicated that the laccase could remove the loosely adhering, unfixed or hydrolyzed dyes from the dyed fabric efficiently, which led to obvious improvements of color fastness. Furthermore, the wavelength of maximum absorbance of the residual solution of dyeing laccase-treated was different from that of the detergent-treated, which implied the laccase could accelerate structural changes of the adhering or hydrolyzed dyes from fabric in treating, resulting in obvious color changes of the residual solution. In addition, excessive laccase also could decolorize a few fixed reactive dyes from the dyed fabric, with a decrease of color strength and less further improvements of color fastness.     

漆酶催化活性及应用研究进展

综述了漆酶催化活性中心结构及特性;漆酶可用于多酚、多氨基等芳香族化合物的降解中,同时在化学合成、纸浆漂白、食品工业及环保方面有重要作用;指出了选育优良菌株,探索适宜的、适合实际生产的培养条件是今后漆酶生产的研究方向。     

漆酶对共基质体系下吲哚的去除研究

网络参与是一种体制外民主参与的新形式,完善了公众参与的手段和渠道。但是,由于存在着非理性、道德缺失等诸多问题和局限性,对民主政治发展产生了一定的消极影响。为了使网络参与走上规范性和有效性辩证互动的发展轨道,伦理的引导和规约必不可少,应对网络参与进行认同与反思前提下的伦理省思,使其在道德规范与制度引导下保持理性限度,并在自由与自律的张力中对网民进行道德约束。