漆酶和聚木糖酶协同漂白蔗渣硫酸盐浆的研究

进行了蔗渣硫酸盐浆漆酶 /介体 (LMS)生物漂白的研究 ,分析了漆酶 /介体体系和聚木糖酶在漂白流程中作为前后漂段或在同一段中同时使用对漂白效果的影响。漆酶 /介体体系与聚木糖酶同时或前后处理蔗渣硫酸盐浆 ,在一定程度上提高了纸浆的漂终白度和强度 ,说明生物漂白改善了漂白选择性     

蔗渣硫酸盐浆漆酶/介体生物漂白流程与工艺的研究

进行了蔗渣硫酸盐浆漆酶 /介体 (LMS)生物漂白流程与工艺的研究。讨论了漆酶的存在和纯化、表面活性剂对LMS的影响 ,分析了碱抽提、螯合处理、酸处理以及压力过氧化氢漂白对漂白结果的影响。检测了含LMS处理的纸浆漂白流程的纸浆性质     

杨木硫酸盐浆在生物酶处理过程中纤维表面积的变化

漆酶 /助剂对杨木硫酸盐浆进行生物漂白 ,用染色法对漂白过程的纸浆纤维的比表面积进行测定。研究结果表明 ,漆酶 /助剂可有效地提高纤维的表面积、白度 ,降低卡伯值 ,而对纸浆的粘度影响不大。     

《纤维素科学与技术》2001年第9卷第1～4期总目录

第 1期固体培养条件下氮源对Ｐａｎｕｓｃｏｎｃｈａｔｕｓ酶系　及漆酶同工酶的影响 (1 )豆壳过氧化物酶的序列联配、二级结构预测　及疏水性分析 (8)细菌纤维素的性质与结构研究 (1 7)蔗渣硫酸盐浆漆酶 /介体生物漂白的影响因素 (2 1 )硫酸盐蒸煮过程中溶出木质素特性的变化 (2 8)施胶剂对纤维素复合材料降解的影响 (35)改性剑麻短纤维 /天然橡胶复合材料的研究　Ⅰ.短纤维预处理方法对复合材料性能的影响(40 )气固相反应制备醋酸纤维素 (45)ＨＥＣ/ＣＭＣ混合物水溶液流变性质的研究 (50 )膳食纤维的研究与开发 (56)第 3期分子结构对乙基…     

国外信息

本研究成功地用电化学法对未漂白蔗渣浆进行了漂白。漂白试验在一个单段中使用氯化钠溶液和直流电进行的,电化学反应器是由一个水平石墨阳极和一个平行的不锈钢网状阴极组成的,化学蔗渣浆、化学机械蔗渣浆和机械蔗渣浆均能被漂白到相当高的白     

漆树漆酶催化甘蔗渣纸浆漂白的研究

利用漆树漆酶在无介体存在条件下对甘蔗渣纸浆进行生物漂白,初步探索了反应时间、漆树漆酶用量、温度及酸度对甘蔗渣纸浆白度的影响。结果表明,在浆浓为3%,漆树漆酶用量1.6 mL/g(对干浆),漂白时间20 min,反应温度20~50℃,pH值为6.1~8.1时,甘蔗渣纸浆白度可提高4%~5%ISO。     

白腐菌对蔗渣浆CEH漂白废水的脱色

蔗渣硫酸盐浆ＣＥＨ漂白废水的颜色主要来自Ｅ段，在导致毒性污染的同时，形成视觉污染。白腐菌是一类担子真菌，能降解植物组织的木素和变性术素如氯化木素，用白腐菌处理蔗渣浆ＣＥＨ漂白废水，可明显降低其色度，而ＣＯＤ与ＢＯＤ值也下降了。吸附固定化白腐菌对废水的脱色能力更强一些，并可连续处理废水。     

漆酶对未漂马尾松磨木浆的酶法改性

利用NS51002和NS51003漆酶/介体分别对马尾松未漂磨石磨木浆(GP)进行生物酶处理及后续的H2O2漂白,并对酶处理浆漂白前后的白度和强度性能进行测定。研究结果表明,利用漆酶NS51003处理马尾松未漂GP,可有效提高纸浆的白度及强度性能,而且酶处理后纸浆具有更好的可漂性,并且经过H2O2漂白后的酶处理浆亦具有更高的白度和更好的强度性能;而漆酶NS51002漆酶/介体对纸浆的改性效果甚微。     

鸡腿菇漆酶同工酶降解马尾松硫酸盐浆中残余木质素的研究

分别利用多组分和单一组分鸡腿菇（Coprinuscomatus）漆酶LHNLc和LLNHc处理马尾松硫酸盐未漂浆,研究二者降解浆中残余木质素的能力。结果表明,上述漆酶降解马尾松硫酸盐浆中残余木质素的优选条件为pH4-2,温度50°C,处理时间5h,酶用量20IU／g（绝干浆）。漆酶LHNLC／紫脲酸体系降解马尾松硫酸盐浆残余木质素能力优于LLNc／紫脲酸体系。经上述两种漆酶／介体体系处理的浆料,其木质素脱出率分别达到35％和31％,比未加漆酶和介体的对照样高64％和62％。比较4种介体对漆酶LHNLc脱木素能力的影响发现,2,2-二氮-双（3-乙基苯并噻唑-6-磺酸）（ABTS）和2,2,6,6-四甲基哌啶-1-氧化物（TEMPO）与漆酶构成的漆酶／介体体系具有相对较强的降解木素能力。     

蔗渣硫酸盐浆次氯酸盐漂白中有害物质的研究

本文对蔗渣硫酸盐浆次氨酸盐漂白中有机氯及三氯甲烷的形成情况进行了研究，结果表明：这些有害物质的生成量与漂白用氟量、漂白浓度、温度和时间等条件有关；在次氨酸盐漂白时加入少量H2O2,可以有效地减少三氯甲烷的生成量，通过GC及ESR分析阐明H2O2能减少废液中三氯甲烷含量的机理。     

芦苇烧碱-蒽醌浆生物漂白的研究

对芦苇烧碱-蒽醌浆进行漆酶/介体体系脱木素处理结合过氧化氢漂序进行漂白。结果表明,分别利用三种介体HBT、VIO和NHA辅助漆酶脱木素,导致浆的白度均有不同程度的降低,降低的幅度与介体种类和用量有关。在相同浓度时,浆白度的降低幅度随介体的氧化还原电势的增大而增大。根据过氧化氢漂白的结果,可以认为LMS-QP最佳处理条件为使用介体NHA,用量为0.5%,漂白时间为2 h。对用2%VIO为介体脱木素后的浆残余木素分析表明,经过漆酶/介体体系处理浆料,浆残余木素中的羰基含量相对提高。     

漆酶与助剂氧化体系降解苇浆残余木素的研究

用溶剂抽提法制取了苇浆残余木素 ,用漆酶 /助剂和氧气与其反应 ,通过甲氧基的测定、元素分析、1 3C -NMR、1 H -NMR和IR分析研究苇浆残余木素与漆酶 /助剂反应前后结构的变化。研究发现苇浆残余木素在反应后其甲氧基、酚羟基减少 ,醇羟基增多 ,木素结构中羰基增多 ,木素的苯环结构发生了开环反应     

Integrating laccase–mediator treatment into an industrial‐type sequence for totally chlorine‐free bleaching of eucalypt kraft pulp

Enzymatic delignification using the high‐redox potential thermostable laccase from the fungus Pycnoporus cinnabarinus and a chemical mediator (1‐hydroxybenzotriazole) was investigated to improve totally chlorine‐free (TCF) bleaching of Eucalyptus globulus kraft pulps. Different points of incorporation of the enzyme treatment into an industrial‐type bleaching sequence (consisting of double oxygen, chelation and peroxide stages) were investigated in pressurized laboratory reactors. The best final pulp properties were obtained using an O? O? L? Q? PoP sequence, where a laccase–mediator stage (L) was incorporated between double oxygen and chelation. The worse results, when the enzymatic and chelation treatments were combined in a unique stage, seemed related to partial inhibition of laccase‐mediator activity by the chelator. The new TCF sequence including the laccase stage permitted to improve eucalypt pulp delignification to values around kappa 5 (hexenuronic acid contribution over 50%) compared to kappa 7 using only TCF chemical reagents. In a similar way, the final brightness obtained, over 91% ISO, was 3–4 points higher than that obtained in the chemical sequences. Although technical and economic issues are to be solved, the results obtained show the feasibility of integrating a laccase–mediator treatment into a TCF sequence for bleaching eucalypt kraft pulp. Copyright © 2006 Society of Chemical Industry     

Investigation of Laccase/N-Hydroxybenzotriazole Delignification of Kraft Pulp

Abstract

N-hydroxybenzotriazole, a mediator for laccase delignification of kraft pulps, was shown to be unstable under the biobleaching conditions. The treatment of N-hydroxybenzotriazole either with laccase alone or in the presence of kraft pulp yielded benzotriazole. The reductive conversion of N-hydroxybenzotriazole to benzotriazole was found to occur rapidly in the presence of pulp. Furthermore, benzotriazole was found to be inactive as a mediator for laccase catalyzed delignification of kraft pulps. Hence, the overall conversion of N-hydroxybenzotriazole to benzotriazole is detrimental towards the bio-delignification process.     

Study on Direct Delignification with Laccase/Xylanase System

Abstract

Direct degradation of lignin with laccase/xylanase system (LXS) instead of the expensive laccase/mediator system (LMS) was investigated. The optimal treatment conditions with LXS were determined. The lignin degrading ability and the physical properties of enzyme treated pulps were compared between LXS and LMS. The results indicated that the optimum treatment conditions of pine kraft pulp with LXS were pH 4.2, temperature 45°, pulp consistency 3%, time 3 h, laccase dosage 10 IU/g. LXS has as strong an ability to delignify with good selectivity as LMS. The strength of pulp was obviously enhanced by LMS treatment to the same extent as LMX when compared with the control at 30 ⁰SR. Thus, LXS can entirely replace expensive and complicated LMS for bio-delignification application.