【作者】 赵敏；

【导师】 王秋玉；

【作者基本信息】 东北林业大学 ， 遗传学， 2009， 硕士

【摘要】 木材腐朽菌对木材的腐蚀是一个复杂的过程,其基因表达过程中,各个基因严格控制着腐朽的过程,各基因功能不同,调节木材理化性质的变化。研究木材腐朽菌对木材腐蚀的机制,及因木材腐朽而引起的化学物质的变化,为进一步研究不同腐朽时期的木腐菌的生理状态及基因表达奠定了理论基础,同时也为抗腐建筑用材的选择以及微生物辅助制浆研究提供了理论依据。本论文用菌丝长度测量法和菌丝体干质量称重法比较了帽儿山采集的桦剥管、木蹄层孔菌、白囊耙齿菌、彩绒革盖菌、黄伞5种木材腐朽菌在固体培养基上的生长速度及在液体培养基中的生物量变化,用比色法检测其与木质素降解相关的酶活性。通过5种菌对300株天然成熟白桦木样的腐朽实验,测定各木腐菌对白桦木材的生物降解能力。应用红外光谱技术,研究了其中4种木材腐朽菌腐蚀木材后对白桦木材官能团的影响。另外,采用mRNA差别显示技术,研究彩绒革盖菌腐蚀白桦木材前后的基因表达差异,进行相关的生物信息学分析,探讨影响木材腐朽的分子机制。研究结果如下:1.5种木材腐朽菌生物量及生物降解能力的测定木材腐朽菌在固体培养基上的生长速度与它在液体培养基中产生的生物量、木质素降解酶活性及其降解木材能力不完全相关;彩绒革盖菌和白囊耙齿菌的生长速度最快,桦剥管菌和木蹄层孔菌中等,黄伞最慢;桦剥管菌的生物量最高,彩绒革盖菌、白囊耙齿菌和木蹄层孔菌生物量中等,黄伞的生物量最低。彩绒革盖菌对白桦木材的生物降解能力最强,其次是木蹄层孔菌和桦剥管菌,白囊耙齿菌和黄伞的生物降解能力最弱。2.5种木材腐朽菌酶活性测定桦剥管菌不表达木质素过氧化物酶、锰过氧化物酶、漆酶活性,其它4种真菌都表达这3种酶活性。白桦木屑诱导下的3种酶活性普遍高于对照样,白囊耙齿菌的漆酶、木蹄层孔菌和黄伞的木质素过氧化物酶只在木屑诱导下表达,而且生长时间越长,酶活越高。3.4种木材腐朽菌对白桦木材官能团的影响桦剥管、木蹄层孔菌、白囊耙齿菌、彩绒革盖菌4种木材腐朽菌及白桦木材为实验材料,采用4种菌对白桦木样腐蚀前后的红外光谱技术分析表明:木材样品经过3种白腐菌——木蹄层孔菌、白囊耙齿菌、彩绒革盖菌的120d的降解,木质素都在一定程度上被降解。虽然苯环骨架变化不明显,但木质素苯环间的羰基、CH₂结构、酚醚键等侧链已部分被降解。而经褐腐菌——桦剥管菌的腐蚀后,木质素并没有发现降解。从各吸收峰相对吸收强度的变化大小来看,木蹄层孔菌、彩绒革盖菌对木质素降解的程度大于白囊耙齿菌对木质素降解的程度。从表征纤维素、半纤维素的震动吸收峰的变化来看,4种木腐菌对纤维素、半纤维素都有降解。4.彩绒革盖菌腐蚀白桦木材前后基因表达初探以帽儿山采集的彩绒革盖菌为实验材料,通过腐蚀帽儿山林场白桦木样获得腐蚀后材料。共筛选到19条特异表达的片段用于后续研究,其中腐蚀白桦木样前11个,腐蚀后8个。更多还原

【Abstract】 It is a complex process in the wood which decayed by wood rot fungi. The gene expression of wood decaying is the complex and rigorous process, each genic function is different, control strictly and adjust the variety of physical and chemical properties. This paper study the mechanism of wood decay fungi on wood corrosion and chemical variety caused by wood decay. The study laid a theoretical foundation for the further study in different decadent period of wood rot fungi during the physiological state and gene expression. At the same time, the paper provide a theoretical basis on choosing decaying resist timbering and biological pulp. In this paper, the growing rate of five wood rot fungi in solid culture medium and their biomass in liquid culture medium was compared. The activity of three main ligninolytic enzymes in those fungi, such as Lip, MnP and Lac, were also tested. At the same time, these fungi were used to decay the wood samples from 300 natural trees of white birch, which to study their wood-decaying capacity by measuring wood weight loss. FTIR spectrometer analysis was used to measure infrared spectrograms of primitive birch wood sample and wood samples degraded by 4 species of fungi, research the effects of functional group. Meanwhile using mRNA differential display to screen the related gene of wood decayed by fungi, analyze the bioinformatics,gene function function, several aspect research were conducted as follows:1. Biomass and Biodegradability of 5 kinds wood decay fungiThe growing rate, biomass, ligninolytic enzymes characteristics and decomposing power of the fungi were incompletely correlation. The growing rate of Coriolus versicolor and Irpex lacteus were faster than that of Piptoporus betulinus and Forties fomentarius, Pholiota adiposa was the slowest. The biomass of Piptoporus betulinus was the highest, Coriolus versicolor, Irpex lacteus and Fomes fomentarius were placed in the middle, Pholiota adiposa is the lowest. The decomposing power of Coriolus versicolor to wood samples was better, and then were Fomes fomentarius and Piptoporus betulinus, Irpex lacteus and Pholiota adiposa were poor.2. Activity determination of 5 kinds wood decay fungiThere existed Lip, MnP and Lac activities in all fungi except Piptoporus betulinus, in which the activities of the enzymes induced by wood powder were all higher than that of the control. The Lac of Irpex lacteus and the Lip of Fomes fomentarius and Pholiota adiposa only expressed in wood powder medium, the longer the fungi were cultured, the higher the enzymatic activites was.3. Impact of functional groups on birch wood decayed by 4 kinds of wood decay fungiUsing 4 kinds of wood rot fungi （Piptoporus betulinus, Fomes fomentarius, Irpex lacteu, Coriolus versicolor ） decay white birch, analyse birch wood with FTIR. Results showed the function groups of wood and lignin were all degraded in different degree by wood white-rot fungi （Fomes fomentarius, Irpex lacteu, Coriolus versicolor）. Although aromatic rings were not changed very much, side chains of lignin such as carbonyl groups, CH₂, syringic units and guaiacyl units were partly degraded. But wood decay by wood brown-fungi （Piptoporus betulinus） lignin was not degraded. The extents of lignin degraded by 3 species of wood rot fungi were different in the view of peak absorption intensity change, Fomes fomentarius and Coriolus versicolor had higher ability than Irpex lacteu in lignin degrading. Connect with the change of peak absorption intensity, cellulose and hemicellulose were all degraded.4. Studies on the gene expression of decay white birch or notChoose the Maoer Mt. Coriolus versicolor for subject and decay white birch wood of Maoer Mt. There were obtained 19 special expression fragments. There were 11 fragments before decay, 8 fragements after decay.更多还原