漆酶对活性艳蓝染料废水脱色

用白腐真菌漆酶对活性艳蓝X-BR和活性艳蓝K-NR 2种活性染料进行脱色实验。研究了pH、温度、染料浓度和酶活力对脱色率的影响。结果表明,漆酶脱色的适宜条件为:反应温度45℃,pH 6～7,适宜染料浓度为50 mg/L,酶浓度5 U/mL,反应1 h两种染料脱色率可达到75%;通过正交实验确定2种染料的最佳脱色组合分别为:反应温度55℃、pH7、活性艳蓝X-BR浓度50 mg/L、酶浓度5 U/mL和反应温度55℃、pH 6、活性艳蓝K-NR浓度50 mg/L、酶浓度5 U/mL。在所得最优条件下反应1 h,活性艳蓝X-BR和活性艳蓝K-NR的脱色率分别为74.2%和78.6%;反应2 h,脱色率分别为78%和79.5%。     

应用漆酶SUKALacc脱色处理纺织染料

印染废水中含有大量的剩余染料,对生态环境构成了巨大威胁.漆酶能够氧化多种纺织染料使其脱色,在印染废水处理领域具有潜在的应用性.为了开发基于酶技术的印染废水处理工艺,利用商业化的漆酶制剂SUKALaccTM对5种常见纺织染料的脱色能力进行了测试,结果显示,SUKALaccTM对于这些测试的染料均具有脱色效果,脱色效率为14.85％～ 85.97％;此外,还考察了酶制剂浓度、染料浓度、温度和pH等因素对脱色效率的影响,确定了最优的反应条件;利用斜生栅藻(Scenedesmus obliquus)和大型溞(Daphnia magna)分别对酶处理后的染料毒性进行了测试,结果表明,酶制剂处理后的染料毒性减弱.这些实验结果为漆酶制剂实际应用于印染废水处理奠定了坚实基础.     

高碘地下卤水中细菌产碘氧化酶的影响因素

高碘地下卤水的细菌碘氧化过程可以减轻工艺管线的生物污损危害。分离自高碘地下卤水中的细菌Roseovarius sp.IOB-7,其分泌的碘氧化酶可催化氧化碘离子生成能够抑制敏感菌生长的碘单质,从而减少生物污损。实验结果显示,加入16μmol/L的Cu~(2+)可促进IOB-7的生长,并将碘氧化酶活力提高了1.75倍。碘氧化酶的最适反应温度为50℃,最适pH为5.5。以碘离子为底物的催化氧化反应中,当pH值为9时,Trametes versicolor漆酶已经完全失活,而碘氧化酶则仍然保持了32%的相对酶活力,显示出更好的pH应用范围和稳定性。开展高碘地下卤水环境中细菌碘氧化酶的研究,对利用生物酶法进行工艺管线生物污损的防治有积极的指导意义。     

漆酶催化复合染料酸性黑ATT脱色的研究

利用白腐菌Ganoderma lucidum wz-32发酵制备的漆酶对印染工业常用的复合染料酸性黑ATT进行催化脱色.在单因子试验的基础上,通过正交优化试验确定酸性黑ATT的最佳脱色条件为:温度50℃,染料浓度0.1 g·L-1,酶量9 U·mL-1,pH 5.0,最适条件下酸性黑ATT的脱色率达87.35%.同时研究了金属离子、酶抑制剂、脱色助剂对酸性黑ATT脱色的影响,结果表明,Co2+、Fe2+、Mn2+、Ca2+、I-对脱色有抑制作用,10mmol·L-1的浓度使脱色率降低了50%以上;Na+、Cu2+在低浓度时对脱色有一定的促进作用;SDS显著抑制漆酶的催化脱色作用,浓度为10mmol·L-1时脱色率降低了68%;HBT是高效的脱色助剂,可显著提高漆酶的脱色效率.     

漆酶催化氧化水中雌激素的研究

采用漆酶催化氧化去除水中5种雌激素(BPA、E2、EE2、E1、OP),探讨了pH和水溶性天然有机质(NOM)对雌激素处理效率的影响,并深入研究了EE2在漆酶催化氧化过程中的反应动力学以及主要的反应产物.结果表明,水中雌激素均可被漆酶有效地去除,其反应的适宜pH值范围为4～6;NOM对5种雌激素的去除效率在反应初期有较明显的抑制作用;漆酶催化氧化EE2的过程遵循二级反应动力学,而在反应过程中,漆酶的稳定性比过氧化物酶要高;由自由基耦合形成的EE2二聚体是漆酶反应的主要产物.     

Migration of heavy metals and migration-degradation of phenanthrene in soil using electro kinetic-laccase combined remediation system

Abstract

In order to solve the problem of heavy metal-organic compound soil pollution, in this paper, we developed a highly efficient electro kinetic-laccase combined remediation (EKLCR) system. The results showed that the EKLCR system had an obvious migration effect on heavy metals (copper and cadmium) and good migration-degradation effect on phenanthrene. The migration rates of copper and cadmium were 48.3% and 40.3%, respectively. Especially, with the presence of laccase, the removal rate of phenanthrene on Cu²⁺-contaminated soil was higher than that of Cd²⁺-contaminated soil due to the significant effect of heavy metals on the enzymatic activity of laccase. The average migration-degradation rate of phenanthrene by EKLCR system was 45.4%. Finally, gas chromatography-mass spectrometry (GC/MS) was used to analyze the degradation intermediates of phenanthrene in the soil, which included 9,10-Phenanthrenequinone, phthalic acid, and 2,2-Biphenyldicarboxylic Acid. In addition, we give the possible degradation pathways of phenanthrene, 2,2-Biphenyldicarboxylic Acid is further degraded to produce phthalic acid. The products of the phthalic acid metabolic pathway are protocatechuic acid, pyruvic acid or succinic acid, the final products of these organic acids are carbon dioxide and water.     

Isolation of a salt tolerant laccase secreting strain of Trichoderma sp. NFCCI-2745 and optimization of culture conditions and assessing its effectiveness in treating saline phenolic effluents

Most of the hazardous pollutants are phenolic in nature and persists in the environment. The ability of laccases to oxidize phenolic compounds and reduce molecular oxygen to water has led to intensive studies of these enzymes. Therefore the fungal strains with high laccase activity and substrate affinity that can tolerate harsh environmental conditions have a potential for biotechnological applications. Salt tolerant laccase secreting fungi can be utilized in treatment of saline and phenolic rich industrial effluents such as coir effluent and textile effluent that needed to be diluted several fold before microbial treatment. This is the first study describing the isolation and optimization of a salt tolerant strain of Trichoderma sp. potential for industrial applications. The fungus was identified based on morphological characteristics and was subsequently confirmed with molecular techniques and deposited at National Fungal Culture Collections of India （NFCCI） under the Accession No. Trichoderma viride NFCCI 2745. In contrast to other laccase secreting fungi, light conditions did not exert much influence on laccase production of this strain and salinity enhanced its laccase secretion. The fungus effectively removed the phenolic content of the textile effluent, coir-ret liquor and wood processing effluent within 96 hr of incubation. The tolerance of the fungus to high salinity and phenolic compounds makes this strain ideal for treating saline and phenolic rich industrial effluents.     

树脂D201上粗漆酶的固定化及对孔雀石绿的脱色

云芝粗漆酶以3种方法,即静电吸附法(D201-Lac-Ⅰ)、先吸附后交联法(D201-Lac-Ⅱ)、戊二醛处理树脂后吸附法(D201-Lac-Ⅲ)固定到大孔阴离子交换树脂D201上.与静电吸附法相比,D201-Lac-Ⅱ的漆酶固载量大幅提升至4.65倍,漆酶比活力却严重受损,只有前者的4.8%;D201-Lac-Ⅲ的漆酶固载量略有下降,为静电吸附法的0.51倍,漆酶比活力却显著提高至静电吸附法的2.99倍.利用电子透射电镜(TEM)可明显观察到D201-Lac-Ⅲ漆酶分子聚合体的阴影.用D201-Lac-Ⅲ对孔雀石绿进行了连续多批次脱色试验,在长达210 h的连续操作中,其脱色效率未观察到有下降趋势,一直稳定在40%～55%之间,D201-Lac-Ⅲ的酶活亦未观察到下降,同等条件下游离的漆酶活力已损失至20%以下,证明D201-Lac-Ⅲ具有显著提升的稳定性和优良的重复利用性.考虑到粗漆酶廉价易得,D201-Lac-Ⅲ在水处理应用中可能大有前景.     

Degradation of Polyethylene and Nylon-66 by the Laccase-Mediator System

We investigated whether the laccase-mediator system (LMS) with 1-hydroxybenzotriazole (HBT) as a mediator could degrade high-molecular-weight polyethylene and nylon-66 membranes. The LMS markedly reduced the elongation and tensile strength of these membranes. After 3 days of treatment with the LMS, the M _w of polyethylene decreased from 242,000 to 28,300, and that of nylon-66 from 79,300 to 14,700. The LMS also decreased the polydispersity (M _w/M _n) of polyethylene and nylon-66. Furthermore, these reductions in elongation, tensile strength, and molecular weight were accompanied by morphological disintegration of the polyethylene and nylon-66 membranes. These results strongly suggest that the LMS with HBT can effectively degrade polyethylene and nylon-66.     

漆酶介体系统对蒽与苯酚共存体系的降解研究

以2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)为介体,研究了漆酶/ABTS介体系统对蒽与苯酚共存体系的降解效果,并考察了不同苯酚浓度对共存体系中蒽降解效果的影响。同时,分析了漆酶/ABTS介体系统对共存体系的作用机理。结果表明,苯酚的引入会抑制蒽的去除,且随着苯酚浓度的增大,蒽降解被抑制地更明显,而蒽对苯酚的降解影响可以忽略不计;蒽体系和蒽与苯酚共存体系中蒽的氧化降解过程均符合一级动力学规律。