活性氧对白腐真菌漆酶合成的影响

分别将不同活性氧在发酵第4天加入发酵产酶培养基中,一定时间后通过测生物量和漆酶酶活研究外界活性氧对白腐真菌漆酶合成的影响,并通过活性电泳进一步验证。结果表明:低浓度的活性氧可以通过信号传导方式调控漆酶合成,超氧阴离子抑制白腐真菌产漆酶,过氧化氢和羟自由基促进白腐真菌产漆酶。实验结果对漆酶合成调控、植物-病原菌相互作用以及生物防护具有重要意义。     

木聚糖酶与白腐真菌

对木聚糖来源、组成、特性、功能以及木聚糖酶的用途、来源进行了综述：介绍了白腐真菌作为产木聚糖酶的一个重要真菌来源的情况，并简要叙述了白腐真菌的知识。     

白腐真菌产木聚糖酶的筛选及其发酵条件研究

从白腐真菌中筛选产木聚糖酶菌株,并研究其产酶条件.从保存的白腐真菌中筛选出了一株产木聚糖酶活较高的菌株.通过单因素和正交试验对该菌株的发酵条件进行了研究.结果表明,5%麸皮和玉米芯(1∶1)为最佳碳源,0.5%蛋白胨为最佳氮源,接种量为每50mL发酵液接4块菌丝块,发酵时间为8.5d,pH值为5.4.优化后的发酵条件显著提高了该菌株产木聚糖酶酶活力.     

白腐真菌转化白酒糟制备高蛋白饲料

白酒酒糟是粮食作物经发酵生产白酒后余下的残渣,含有大量的淀粉、蛋白质及发酵菌体残渣等营养物质,是可被再利用的生物质资源。传统的酒糟处理主要是直接作为动物饲料等加以利用,附加值较低。聚焦白酒糟中的主要成分——木质素,结合真菌生长发育的过程及特征,探讨了以真菌转化白酒糟制备高附加值饲料的可能性。     

应用白腐真菌处理亚铵制浆废液

亚按法制浆废液的利用一、直受到人们极大的关注，是由于它的废液呈中性，并含有大量有机物和N、P、K等营养成分。1967年，我校开始研究亚按法制浆废液的肥料效应。结果证明，它是一种很好的农田肥料，对农作物有不同程度的增产作用；对土壤有一定的保温、保墒作用。但由于废液量大，浓度低，不好贮存，如果解决不好工厂常年生产和农业季节性灌溉的矛盾，在农业非灌溉时期，大量废液只能直接排放，既污染了环境，又浪费了资源。亚铁制浆废液中所含的还原糖（单精、双搪）、氨态氮、粗蛋白、有机酸等，都是易为微生物利用的营养成分，经转…     

白腐真菌对玉米秸杆和餐厨垃圾堆肥效果的影响

利用白腐真菌降解过的玉米秸秆和未降解过的玉米秸秆分别与餐厨垃圾进行堆肥对比实验,研究生物预处理对秸秆堆肥效果的影响.在30d的堆肥过程中,通过测定堆体的温度、含水率、pH、有机质含量以及种子发芽指数指标评价其堆肥效果和腐熟程度.结果表明,预处理过的秸秆堆体A较未处理过的堆体B先达到55℃;堆体A含水率下降迅速、有机质含量减少快,可缩短堆肥周期;两堆体pH最终接近中性;堆体A种子发芽率为99%,比堆体B的种子发芽率高1%,堆体A的腐熟速度和程度优于堆体B.生物预处理可加快堆肥进程,有效缩短堆肥周期.     

20种中草药水提液对白腐菌和褐腐菌的抑菌作用

以大量对真菌有抑菌效果的中草药作为实验材料,旨在寻找筛选对抑制木腐菌生长有效的单味中药,寻找新型木材防腐剂。通过对20种中草药的抑菌圈实验,得出对白腐菌抑菌效果最好的中药是皂角和川椒,皂角的抑菌效果最好,其余中药也有不同程度的抑菌作用。而对褐腐菌抑菌效果最好的中药是皂角,其余中药对木腐菌的抑菌效果不明显。     

废纸脱墨浆的无氯漂白中添加表面活性剂对漂后浆的白度和强度的影响

本文根据表面活性剂的特性,从提高漂后浆的白度和浆纸的强度出发,进行了废纸脱墨浆的H2O漂白中添加表面活性剂的初步探讨.     

白腐真菌处理染料孔雀石绿的研究

实验研究了白腐真菌B在不同振荡条件下、不同染料浓度、不同碳源浓度等环境因素对孔雀石绿脱色效果的影响。实验结果表明菌株B在染料浓度为100mg·L-1,振荡速度为150r·min-1,碳源浓度为20g·L-1时,其脱色率最高。     

白腐菌协同碱性H2O2杨木脱木素及其机理

在没有外源营养时，白腐菌能在杨木片上生长，并对杨木片木素成分有明显的降解作用；白腐菌协同碱性过氧化氢能进一步增加对杨木片木素成分的脱除作用，与碱性过氧化氢单独处理相比较，对酸溶木素的脱除作用不明显；白腐菌对杨木片木素的降解以氧化反应为主，其中对愈创木基的降解作用大于紫丁香基，残余木素分子中的-CH3和-OH基含量均有增加，羰基的数量也增加了；白腐菌协同碱性过氧化氢处理对杨木片细胞角部位的木素脱除率明显高于胞间层。     

黄孢原毛平革菌的固态培养条件及菌剂干燥保存条件研究

对白腐菌的典型种黄孢原毛平革菌(P.chrysosporium)的固态培养条件及最优培养条件下培养的固态菌剂的干燥保存条件进行了研究.结果表明,37℃培养7d多碳少氮条件更利于该菌的生长和产孢,分别在第10 d和第12d其产Lip和Mnp酶活力达到最高;相关性分析表明,菌剂的含水量与其活孢子含量之间呈强正线性关系,实际应用中可根据不同要求而采用不同的干燥方法.     

黄孢原毛平革菌合成锰过氧化物酶的工艺

研究了多种营养条件及培养条件对黄孢原毛平革菌 (Phanerochaetechrysosporium )WX2 13合成锰过氧化物酶的影响 .当培养基中葡萄糖质量浓度为 10 g/L ,酒石酸铵质量浓度为0 .2 g/L,吐温 80质量浓度为 1g/L ,MnSO4 ·H2 O为 0 .14g/L ,采用苯二甲酸缓冲液 ,最终pH 4 .5 ,2 5 0mL的三角瓶装液量 90mL ,接种量为 1.2× 10 6mL- 1时所获酶活较高 .经条件优化后锰过氧化物酶的活力达到 5 5 9U/L ,比未优化前提高了 36% .加入染料培养 ,发现该酶对所选用的偶氮染料、三苯甲烷类染料、杂环类染料均有较好的脱色效果     

黄孢原毛平革菌产蛋白酶对过氧化物酶的影响

在培养黄孢原毛平革菌产生木质素过氧化物酶(LiP)和锰过氧化物酶(MnP)过程中产生的胞外蛋白酶与LiP和MnP的快速失活有关.该蛋白酶在pH 7的条件下酶活很高,其主要作用是促进LiP和MnP的分解,而不是抑制它们的产生.HgCl2是蛋白酶的抑制剂,其抑制机理类似于HgCl2对蛋白酶K(PK)的抑制.添加HgCl2的发酵液能提高过氧化物酶的酶活和稳定性,最佳添加量为1 μmol/L,最佳添加时间在接种后第5天.     

紫外线照射白腐菌对己内酰胺分解及聚酰胺6降解的影响

为减少废弃己内酰胺及聚酰胺6对环境的污染,采用紫外线对白腐菌进行诱变,以提高其对己内酰胺的生物分解和对聚酰胺6的生物降解性能。研究结果表明:白腐菌对己内酰胺有较好的生物分解性;紫外线诱变后白腐菌对己内酰胺的分解性能有很大提高;诱变后的白腐菌对聚酰胺6薄膜有很明显的刻蚀,降解效果较好;对聚酰胺6纤维也有较明显的刻蚀斑痕,从而可实现微生物对己内酰胺的生物分解及对聚酰胺6的生物降解。     

黄孢原毛平革菌对大豆秸秆木质素降解的FTIR表征

研究黄孢原毛平革菌(Phanerochaete chrysosporium Burdsall)对大豆秸秆中木质纤维素的降解条件。结果显示：5g秸秆粉中添加合成培养液12mL、接种量为0.8mL(孢子悬液浓度8.6×106CFU/mL)、培养基初始pH4.5,发酵10d后,木质素降解率为45.96%。并采用傅里叶红外光谱分析(Fourier transform infrared spectroscopy,FTIR) 检测降解后秸秆中官能团的变化,发现与木质素相关的谱峰(1099cm-1、1057～1038cm-1)相对强度减小,与苯环相关的谱峰(1643～1608cm-1、1510～1508cm-1)相对强度增加,表明部分大分子木质素裂解成小分子木质素或木质素单体,对比其他谱峰相对强度的变化,发现木质素中苯环等环状化合物含量减少。     

Effect of chemical pretreatments on the fermentation and ultimate digestibility of bagasse by Phanerochaete chrysosporium

When sugarcane bagasse was pretreated at room temperature with various chemicals singly or in combination, (0.25 m NaOH; 0.5 m H₂SO₄; 2.6 M NH₃;0.14 M Ca(OH)₂+0.12 M Na₂CO₃;4.2 m EDA; and 0.5 M H₂SO₄ or 0.25 M NaOH followed by 4.2 M EDA), increases in in-vitro digestibility range from 28.9 to 48.6% depending on the particular chemicals. With most pretreatments, the hemicellulose content decreased and the cellulose content increased slightly, while lignin levels decreased only with NaOH + EDA pretreatments. Further fermentation of the chemically pretreated bagasse with Phanerochaete chrysosporium gave increased digestibilities, the highest final digestibility (59%) being achieved by pre-treatment with 0.25 M NaOH. Pretreatment with NaOH or Ca(OH)₂+Na₂CO₃ and fermentation gave greatly increased levels of hemi-cellulose and cellulose and substantial decreases in lignin levels. Chemical pretreatments of bagasse together with autoclaving considerably enhanced in-vitro digestibility (up to 75%) and lignin degradation (1.4%). Pretreatment with NaOH, Ca(OH)₂+Na₂CO₃, and EDA plus autoclaving gave large increases in total hemicelluloses and cellulose and marked decreases in lignin. Further fermentation with P. chrysosporium gave only slight increases in digestibility.     

Acetylated Xylan Degradation by Glycoside Hydrolase Family 10 and 11 Xylanases from the White-rot Fungus Phanerochaete chrysosporium

Endo-type xylanases are key enzymes in microbial xylanolytic systems, and xylanases belonging to glycoside hydrolase (GH) families 10 or 11 are the major enzymes degrading xylan in nature. These enzymes have typically been characterized using xylan prepared by alkaline extraction, which removes acetyl sidechains from the substrate, and thus the effect of acetyl groups on xylan degradation remains unclear. Here, we compare the ability of GH10 and 11 xylanases, PcXyn10A and PcXyn11B, from the white-rot basidiomycete Phanerochaete chrysosporium to degrade acetylated and deacetylated xylan from various plants. Product quantification revealed that PcXyn10A effectively degraded both acetylated xylan extracted from Arabidopsis thaliana and the deacetylated xylan obtained by alkaline treatment, generating xylooligosaccharides. In contrast, PcXyn11B showed limited activity towards acetyl xylan, but showed significantly increased activity after deacetylation of the xylan. Polysaccharide analysis using carbohydrate gel electrophoresis showed that PcXyn11B generated a broad range of products from native acetylated xylans extracted from birch wood and rice straw, including large residual xylooligosaccharides, while non-acetylated xylan from Japanese cedar was readily degraded into xylooligosaccharides. These results suggest that the degradability of native xylan by GH11 xylanases is highly dependent on the extent of acetyl group substitution. Analysis of 31 fungal genomes in the Carbohydrate-Active enZymes database indicated that the presence of GH11 xylanases is correlated to that of carbohydrate esterase (CE) family 1 acetyl xylan esterases (AXEs), while this is not the case for GH10 xylanases. These findings may imply co-evolution of GH11 xylanases and CE1 AXEs.     

Effect of C-6 Methylol Groups on Substrate Recognition of Glucose/Xylose Mixed Oligosaccharides by Cellobiose Dehydrogenase from the Basidiomycete Phanerochaete chrysosporium

Cellobiose dehydrogenase (CDH) is a flavocytochrome catalyzing oxidation of the reducing end of cellobiose and cellooligosaccharides, and has a key role in the degradation of cellulosic biomass by filamentous fungi. Here, we use a lineup of glucose/xylose-mixed β-1,4-linked disaccharides and trisaccharides, enzymatically synthesized by means of the reverse reaction of cellobiose phosphorylase and cellodextrin phosphorylase, to investigate the substrate recognition of CDH. We found that CDH utilizes β-D-xylopyranosyl-(1→4)-D-glucopyranose (Xyl-Glc) as an electron donor with similar K _m and k _cat values to cellobiose. β-D-Glucopyranosyl-(1→4)-D-xylopyranose (Glc-Xyl) shows a higher K _m value, while xylobiose does not serve as a substrate. Trisaccharides show similar behavior; i.e., trisaccharides with cellobiose and Xyl-Glc units at the reducing end show similar kinetics, while the enzyme was less active towards those with Glc-Xyl, and inactive towards those with xylobiose. We also use docking simulation to evaluate substrate recognition of the disaccharides, and we discuss possible molecular mechanisms of substrate recognition by CDH.     

黄孢原毛平革菌对美洲黑杨的生物制浆研究

以短周期工业材美洲黑杨为原料 ,选用黄孢原毛平革菌PhanerochaetechrysosporiumME44 6及其木素过氧化物酶缺陷株LIP - 14进行了一系列生物制浆实验。原始菌株P .C .ME45 6预处理后节约磨浆能耗 38% ,LIP - 14节约磨浆能耗 2 4.5 %。突变株LIP - 14在提高纸张物理强度方面明显优越于原始菌株 ,其中对裂断长的提高比P .C .ME44 6高出 2 6 % ,耐破度的提高比P .C .ME44 6高出 2 0 % ,撕裂度的提高则比P .C .ME44 6高出 47%。LIP - 14预处理后大大改善了生物机械浆的质量 ,是适合于美洲黑杨生物制浆的优良菌株。     

白腐菌处理漂白废水工艺及脱色机理探讨

本文设计了一种适合于白腐菌ｐｈａｎｅｒｏｃｈａｅｔｅ ｃｈｒｙｓｏｓｐｏｒｉｕｍ 处理漂白废水的活性炭———化学纤维固定膜反应器,对漂白废水的脱色率达６０ ％ ～９０ ％ ,ＣＯＤｃｒ 去除率在５０ ％ 以上。本文还探讨了菌膜生长的营养条件和废水组成对处理效果的影响。最后通过用Ｈ２Ｏ２ 对废水进行的脱色处理,验证了白腐菌脱色类似于Ｈ２Ｏ２ 的作用。