木质素改良粉土基本工程特性试验研究

将工业副产品木质素应用于粉土改良.通过界限含水率、颗分、击实、无侧限抗压强度和电阻率等室内试验,对素土及掺木质素改良土的基本物理力学性质、p H值和电学特性等进行对比研究,明确改良土的基本工程特性变化规律和改良效果,并采用扫描电子显微镜(SEM)对土体微观结构变化进行对比分析,阐述了木质素与土体的相互作用机理.试验结果表明:木质素可有效改善粉土的颗粒级配,降低土体的塑性指数;改良后粉土的最大干密度增加,最佳含水率减小,同时干密度对含水率变化的敏感性增强;改良土的无侧限抗压强度优于素土,p H值低于10,龄期和含水率对强度影响显著,对p H值无明显影响;胶结物质填充孔隙并联结土颗粒,改良土微观结构更为稳定.这说明木质素可有效改善粉土的基本工程特性.     

大麻处理工艺

大麻原麻属于高木质素含量麻种。以去除木质素为主要目的，对传统的原麻化学脱胶工艺进行了改造，采用无酸重二煮的工艺方法制取大麻的精干麻，取得了明显效果。     

利用造纸黑液制取改性木质素磺酸钠

用硫酸沉淀回收造纸黑液中的木质素，并经Na2SO3磺化、HCHO羟甲基活化和缩聚处理制备出改性木质素磺酸钠．探讨了木质素回收、磺化和改性处理的工艺条件．制备出的改性木质素磺酸钠用作防垢剂．分散性能良好。     

微生物与嫩竹土法造纸

嫩竹土法造纸已有二千余年历史。其工艺是用石灰浸泡、联合微生物作用,以降解嫩竹中木素及部分半纤维素,达到制浆、造纸的目的。微生物以细菌为主,还有些原生动物与真菌。从分离出的１００株细菌中,６０株为芽胞杆菌,其余为肠杆菌科（埃希氏菌、枸椽酸杆菌）、不动杆菌、黄色杆菌、假单胞菌、醋酸杆菌、产碱杆菌、葡萄球菌、微球菌、李氏杆菌等。能使嫩竹软化的３株细菌均为芽胞杆菌,其中１株（３０８号）为短小芽胞杆菌。嫩竹经石灰处理后,以分得的３０８号短小芽胞杆菌处理４ｄ,可将嫩竹软化造纸,使土法的数月到１年的生产周期缩短为２４ｄ。判断木素降解的经验方法,是以手捏竹片。它是简易可行的有效方法。古代的工艺及其可改造处,曾予以讨论。     

木素过氧化物酶合成的部分影响因素

研究了黄孢原毛平革菌（Ｐｈａｎｅｒｏｃｈａｅｔｅｃｈｒｙｓｏｓｐｏｒｉｕｍ）在以０．４％微晶纤维素为碳源、２０ｍＭＮＨ＋４氮源的富碳富氮液体振荡培养条件下,木素过氧化物酶与起始ｐＨ值、诱导剂、孢子年龄、添加吐温及碳源设置的关系。试验结果显示,起始ｐＨ值６．０所得酶活最高,黎芦醇诱导效果明显。添加吐温、少量单糖可明显提高酶产量。     

Characterization of threerice CCoAOMT genes

Caffeoyl-Coenzyme A 3-O-Methyltransferase (CCoAOMT) is a key enzyme in lignin biosynthesis pathway. Three rice CCoAOMT genes were identified and designated as OsCOAI, OsCOA20 and OsCOA26. OsCOAI contains four exons and three introns, while the other two have three exons and two introns. The deduced amino acid sequences of these rice genes share a high identity (75.43%) with other plant CCoAOMT proteins and contain the CCoAOMT specific motifs. Phylogenetic analysis indicates that OsCOAI has the closest evolutionary relationship to maize CCoAOMT. In contrast, OsCOA20 and OsCOA26 belong to another clade.Northern blot analyses and in situ hybridization studies indicate that the three rice CCoAOMT genes are highly expressed in developing sclerenchyma cells and vessel bundles of young leaves, suggesting that they are probably involved in constitutive lignification.     

Obtaining the transgenic poplars with low lignin content through down-regulation of 4CL

The antisense 4CL (4-coumarate: CoA ligase)gene was transformed into triploid Chinese white poplar(Populus tomentosa) mediated by Agrobacterium tumefaciens.PCR and Southern blot analysis indicated that antisense 4CLgene had been integrated into the genome of the transgenicChinese white poplars. The antisense gene had also beenexpressed, which was indicated by RT-PCR and Westernanalysis. Klason lignin content assay showed that repressionof 4CL expression could result in remarkable reduction oflignin content in transgenic poplars, with most reduction of 41.73% compared with that of wild type in this paper. Butthere is no significant difference in holocellulose content be-tween trans- genic and wild poplars. We considered that 4CLmight not be the metabolism control point between ligninand carbohy- drate biosynthesis. The stems of transgenicpoplars displayed red-brown color with different levels afterthe bark was peeled, while those of untransformed plantswere white. No visible differences in growth and developmentwere observed between transgenic and wild plants. Wiesnerreaction analysis of the transgenic plant stems with reducedlignin content exhibited red color, while that of untrans-formed plant was typically purple-red.     

转基因抗虫棉花木质素含量及其生物合成关键酶活性研究

通过盆栽试验,以不同转基因抗虫棉花及其亲本对照为供试对象,研究木质素含量及其生物合成关键酶活性.结果表明:与非转基因棉花比较,在蕾期及铃期,转基因抗虫棉花Z30,CCRI41,SGK321叶片、茎秆组织中的木质素含量及叶片内的苯丙氨酸解氨酶和过氧化物酶活性发生了一些变化,但其显著性改变仅特异性地发生在某些品种、某些组织或某些时期内.在蕾期,转Bt基因棉花Z30茎秆组织中的木质素含量比其常规棉对照Z16显著下降,幅度达34.96%;转CpTI-Bt棉花CCRI41茎秆组织和SGK321叶片组织中的木质素含量比其常规棉对照显著下降,幅度分别为27.15%,13.22%.所有供试转基因抗虫棉花的木质...     

两性木质素絮凝剂的制备及脱色性能研究

木素磺酸钙与丙烯酰胺接枝共聚物通过Mannich反应,得到两性木素絮凝剂LSM.由正交实验得到Mannich反应较佳条件为:醛胺比1∶1,反应温度50℃,反应时间2.0 h,在此条件下LSM具有较佳的脱色性能.并将LSM用于活性艳蓝X-BR、活性黄X-R、活性紫K-3R、活性黑K-BR、直接橙S等多种模拟染料废水的脱色处理,讨论了LSM投加量和溶液pH值对不同染料脱色效果的影响.实验结果说明,LSM对各染料有较好的脱色效果,脱色率均在82%以上.同时投加量增加可能引起废水CODcr的提高,需控制适当的投加量范围.     

白腐菌对秸秆中木质素生物降解的研究

研究了白腐菌及其产生的木质素降解酶系对秸秆的木质素生物降解方法，探讨了黄孢原毛平革菌和杂色云芝单一菌株生物降解及双菌株联合降解木质纤维素的规律，白腐菌双菌联合固态培养可使木质素降解率达到47．64％，脱木素选择性为4．74．采用模拟大规模白腐菌堆积培养（厚度30cm）的方法降解秸秆木质素，培养30d，木素降解率为32．54％，表明此方法是一种可行的大规模生物顸处理方法．