Biodegradation and Sugar Release from Canola Plant Biomass by Selected White Rot Fungi

Canola crop is rich in plant biomass. It is considered a major cash crop in North America and a potential source for biofuel. We evaluated six strains of white rot basidiomycetes under solid state fermentation (SSF) for their potentials to secrete oxidative and hydrolytic enzymes to biodegrade canola plant biomass (CPB), and release sugars. Fuscoporia gilva and Pleurotus tuberregium produced high amount of laccase (440.86 U/L and 480.63 U/L at day 7), as well as carboxylmethylcellulase (CMCase) (4.78 U/mL at day 21 and 3.13 U/mL at day 14) and xylanase (4.48 U/mL and 7.8 U/mL at day 21), respectively. Bjerkandera adusta showed high amount of MnP (50.4 U/L) and peroxidase (64.5 U/L), relative to the other strains. Loss of organic matter peaked after 21 days of incubation in all the tested strains;however, the best result (34.0%) was shown in P. tuberregium. The highest lignin loss was observed in Coriolopsis caperata strains. Among the sugar polymers, hemicellulose was highly degraded by P. tuberregium and P. pulmonarius (4.1% - 4.6%), while cellulose (3.3% - 4.3%) was mainly degraded by F. gilva and B. adusta. Glucose was the dominant sugar released by all the fungi tested, with the highest concentration of 1.25 mg/mL produced by B. adusta at day 14 of incubation. Results indicate that selected white rot fungi can achieve significant delignification of CPB within 14 days of solid state fermentation. Their importance in low cost pretreatment of lignocellulosic biomass prior to conversion into biofuels and bio-products of economic importance is discussed.

Degradation of lignite model compounds by the action of white rot fungi

Three compounds modeled on the lignite structure were chosen for experimental degradation by different fungi strains. Culture conditions and extracellular enzyme activities were optimized. The growth curves of the strains were determined to study mycelium dry weight and protein content changes. Gas chromatography and infrared spectroscopy were used to detect changes of functional groups before and after the action of the fungi on the model compounds. Possible decomposition products and degrada-tion mechanisms were proposed. The research findings show that C. Versicolor and Golden Mushroom can grow in presence of the model compounds. The optimum culture conditions were a pH of 6.0, a carbon-nitrogen ratio of five and a Tween-80 concentration of 0.1%. Newly produced substances were found by gas chromatography. Infrared analysis showed that the model compounds degraded under the action of the microorganisms.

Effects of White-Rot Fungi Composting on Wood Powder-Chicken Manure Mixture

[ Objective] To explore the possibility of treating livestock manure with white-rot fungi. [Method] The wood powder-chicken manure mixture was respectively composted by three kinds of white-rot fungi, the weight of lignin, cellulose, protein, fat, ash and crude polysaccharide as well as the mycelial growth was determined during this process. [ Result] The mixture was better composted with white-rot fungi than the control. The best effect was achieved in P. ostreatus composting group. In this group, the rate of weight reduction, lignin degradation and cellulose degradation were respectively 15.68% （6.79 times as great as that of the control group）, 39.92% （6.54 times as great as that of the control group） and 32.26% （2.77 times as great as that of the control group）. The weight of protein and fat were increased by 31.68% and 146.58%, respectively. The content of crude polysaccharide was 2.43%. No crude polysaccharide was detected, and the weight of protein and fat decreased by 21.96% and 70.99%, respectively. [ Conclusion] It is feasible to compost livestock and poultry manure with white-rot fungi.

Enzymatic activities and kinetic properties of β-glucosidase from selected white rot fungi

Beta-glucosidase is among the suite of enzymes produced by white rot fungi (WRF) to biodegrade plant biomass. This study investigated the enzymatic activities and kinetic properties of β-glucosidase from seventeen WRF comprised of the following species from various geographical locations: Pleurotus ostreatus, Auricularia auricular, Polyporus squamosus, Trametes versicolor, Lentinula edodes, and Grifola frondosa. All the WRF studied showed β-glucosidase activities. Significant variations in protein and carbohydrate contents were also recorded. Beta-glucosidase activities after 30 min of incubation ranged from 6.4 μg (T. versicolor) to 225 μg (G. frondosa). The calculated kinetic constant (Km) ranged from 0.47 μM (A. auricular-1120) to 719 μM (L. edodes-7). The Vmax depending on the kinetic transformation model ranged from 0.21 μg·min-1 (T. versicolor) to 9.70 μg·min-1 (G. frondosa-28). Beta-glucosidase activities also exhibited pH optima between 3.5 and 5.0 while temperature optima were between 60°C and 70°C with some media exhibiting a secondary temperature peak at 90°C attributable to the presence of thermostable isoenzyme. WRF if appropriately screened and purified can be harnessed to potentially improve the bio-conversion of cellulose to glucose and also facilitate efficient plant biomass biodegradation and production of useful plant bio-products.

BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus, Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus florida and Panus conchatus were selective to degrade lignin in reed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose, which was not good for biopulping.

Transcriptome Analysis of White-Rot Fungi in Response to Lignocellulose or Lignocellulose-Derived Material Using RNA Sequencing Technology

White-rot fungi are the only organisms that can completely degrade all components of lignocellulosic biomass, including the recalcitrant lignin polymer. Lignin degradation is important for the industrial application of lignocellulosic biomass as a raw material for producing value-added chemicals and materials. Therefore, elucidating the lignin degradation mechanism in white-rot fungi will help researchers develop efficient and eco-friendly methods enabling the production of value-added chemicals from lignocellulosic biomass. A transcriptome analysis is an effective way to compare gene expression patterns between different samples under diverse conditions and can provide insights into biological processes. The democratization of next-generation sequencing technology, especially RNA-sequencing, has made transcriptome sequencing and analysis a common research approach for many laboratories. In this review, we focus on the transcriptome profiles of two well-characterized white-rot fungi (Phanerochaete chrysosporium and Dichomitus squalens) in response to various lignocellulosic materials. The application of RNA-seq technology combining with other techniques remains the best approach for investigating fungal secretomes and elucidating the mechanisms of fungal responses to lignocellulose.

Conditional Optimization of Laccase Production by Whiterot Fungi through Fermentation

Phanerochaete chrysosporium was selected as the production strain of laccase,and the effects of stirring speed,ventilation volume,culture temperature,inoculation amount and initial p H of medium on laccase production by liquid fermentation in cylinder were studied. On the basis of single factor test,an orthogonal test was carried out to find optimal conditions for laccase production P. chrysosporium through liquid fermentation. These results showed that the stirring speed of fermentation cylinder had the highest effect on laccase production,and the optimal conditions were shown as follows： the temperature at 28 ℃,the rotating speed at 300 r/min,the ventilation volume of 5 L/min（ ventilation ratio of 1.0 vvm）,the initial p H of medium of 5,and the inoculation amount of 15%,which gave the highest laccase level of 14. 86 U/ml.

活检组织中真菌Calcofluor White荧光染色法的改良

目的:探索对Calcofluor White荧光染色法的改良,为活检诊断真菌感染提供一种快速、经济、对比更清晰的染色方法。方法:采用Calcofluor White M2R和苏木素、伊红染液,组合成3种染色步骤,对32例病例进行染色,筛选出适用于活检组织,并且在光镜与荧光镜下能同时观察的改良染色法步骤。结果:光镜下,组织呈现HE染色固有的形态。切换至荧光显微镜下,真菌则被显示为亮蓝色,组织背景呈黄绿色,结果清晰、醒目,对比强烈。结论:改良Calcofluor White荧光染色法能使同一张切片在光镜和荧光显微镜下同时观察,相互对照和定位,是提高真菌检出的好方法,值得在真菌的病理活检工作中广泛使用。

Experimental Study on Decolorization and Degradation of Reactive Brilliant Red X-3B in a White Rot Fungal Biofilm Reactor

Experimental results of an azo dye(reactive brilliant red X 3B, RBR X 3B) decolorization and degradation in a white rot fungal biofilm reactor were introduced and discussed. The fungal biofilm reactor is highly potential for dye decolorization and degradation with the highest decoloring rate of 95% within 96 hours reaction time at initial pH 4.5 under high nitrogen level (HN) (24 mmol/L ammonium tartrate) condition. Experimental conditions, such as nutrient nitrogen levels in reaction mixture and initial pH, significantly affected dye decolorization and degradation. Effluents from this biofilm reactor can be well treated to meet the discharging requirements by use of chemical flocculation.RBR X 3B was first absorbed onto fungal biomass and then degraded gradually. The SH 13 fungus monopolized the biofilm throughout the experiments, though the reactor was exposed to open air for 4 months.

丛枝菌根真菌和根瘤菌对白三叶氮同化的影响

为揭示丛枝菌根真菌(AMF)和根瘤菌在白三叶氮(N)同化中的作用,该研究对白三叶进行单一或联合接种隐类球囊霉(Paraglomus occultum)和三叶草根瘤菌(Rhizobium trifolii),分析其对白三叶的生长、光合作用、叶片N和氨基酸含量以及N同化相关酶活性的影响。结果表明:(1)单一接种AMF或根瘤菌以及联合接种AMF和根瘤菌均显著增加了白三叶的株高、匍匐茎长度、叶片数、地上部生物量、总生物量、叶绿素b和总叶绿素含量、稳态光量子效率和叶片N含量,这种增强效应是联合接种>单一AMF>单一根瘤菌>未接种处理。(2)联合接种AMF和根瘤菌显著增加了白三叶叶片中丙氨酸、精氨酸、天冬酰胺、天冬氨酸、谷氨酰胺、谷氨酸和组氨酸的含量,显著提升了叶片N同化相关酶如硝酸还原酶、亚硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶、谷氨酸脱氢酶、天冬酰胺合成酶和天冬氨酸转氨酶的活性,显著促进AMF对白三叶根系的侵染。综上认为,联合接种AMF和根瘤菌通过激活N同化相关酶活性有效促进N同化,产生更多氨基酸,进一步促进白三叶植株生长;联合接种AMF和根瘤菌具有协同作用,有效促进了白三叶的N同化。

香菇等食用菌固态发酵对白芸豆营养成分及抗氧化活性的影响

通过接种5种食用菌(香菇、平菇、羊肚菌、猴头菇、鸡腿菇)菌丝体进行固态发酵,研究其对白芸豆颗粒结构、营养成分及抗氧化活性的影响.结果表明,经食用菌固态发酵后白芸豆粉末粒径分布明显降低(P<0.05),灰分和总蛋白质含量显著升高(P<0.05),碳水化合物含量降低.食用菌固态发酵后的白芸豆总酚含量显著升高(P<0.05),对照组的总酚含量为104.85 mg GA/(100 g),经香菇、平菇、羊肚菌、猴头菇和鸡腿菇发酵后白芸豆总酚含量分别提高到389.10、340.04、168.80、345.65和252.31 mg GA/(100 g).食用菌固态发酵后白芸豆的抗氧化活性(DPPH自由基清除能力、ABTS+自由基清除能力)显著增强(P<0.05).相关性分析表明,总酚含量与ABTS+自由基清除率呈正相关(r=0.916,P<0.05).对白芸豆品质提升效果依次为香菇、平菇、羊肚菌、猴头、鸡腿菇.结果表明食用菌固态发酵显著改善了白芸豆的营养品质和抗氧化活性,尤其以香菇和平菇效果最好,这为白芸豆的深加工和功能化产品的开发提供理论依据和实践指导.

迷宫栓孔菌热激蛋白基因的生物信息学与表达分析

为了探究迷宫栓孔菌(Trametes gibbosa)热激蛋白(heat shock proteins,HSPs)家族的功能及结构,对经木屑处理不同时间点的菌丝样品进行cDNA建库,然后根据转录组数据筛选该菌株的所有HSPs基因并进行生物信息学分析;针对HSP100家族进行基因克隆和序列结构分析,并利用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,qRT-PCR)对其在木屑处理下的表达量进行验证。结果如下:在迷宫栓孔菌中共筛选出32个HSPs基因,其编码的蛋白分为5个亚类,分别为HSP100(2个)、HSP90(2个)、HSP70(7个)、HSP60(1个)和小分子热激蛋白[small HSPs(sHSPs),20个],它们在菌体生长调控中具有蛋白翻译后修饰、蛋白质折叠、伴侣蛋白等重要功能。这些HSPs都为疏水蛋白,不同亚类的HSPs理化性质有所差异。HSP100由N-端、核苷酸结合域1(nucleotide-binding domain 1,NBD1)、NBD2、2个NBDs间的接头构成,其中,NBDs具有十分保守的Walker A、Walker B基序及精氨酸指残基。qRT-PCR扩增结果表明,在木屑处理下迷宫栓孔菌HSP100基因表达量有明显上调趋势。综上所述,迷宫栓孔菌中HSPs家族种类多且复杂,在应激情况下HSP100家族承担了重要的蛋白质解聚功能,其序列及结构相对保守。本研究结果为迷宫栓孔菌在胁迫应激方面的研究提供了理论依据。

木霉菌对白腐真菌所致木材腐朽防效研究

筛选有效抑制白腐真菌生长并降低其对木材腐朽能力的生防菌株,为白腐真菌所致木材腐朽的生物防治提供新思路。以樟子松(Pinus sylvestris)倒木中分离纯化的3株木霉(Trichoderma spp.)作为生防菌株,利用离体对峙培养法测定分离菌株对多种白腐真菌的拮抗效果,结合形态学、分子生物学和系统进化树分析对拮抗效果较好的真菌进行鉴定,并通过检测生防真菌的代谢产物及其与白腐真菌菌丝间的作用关系初步探究其生防机制,最后利用质量损失法检测该生防菌株防治白腐真菌对樟子松木材腐朽的能力。结果表明:筛选得到1株有较好拮抗效果的生防真菌SF2,对峙培养8 d时,该菌株对5种白腐真菌的抑菌率从高到低排序为白囊耙齿菌(Irpex lacteus)>一色齿毛菌(Cerrena unicolor)>粗毛拟革盖菌(Coriolopsis aspera)>彩绒革盖菌(Coriolus versicolor)>裂褶菌(Schizophyllum commune);经过形态观察、ITS1/ITS4 DNA序列扩增比对和系统发育树分析,发现SF2菌株属于长枝木霉(Trichoderma longibrachiatum);生防菌对白腐真菌的抑菌机理显示,菌株SF2可以通过重寄生以及分泌代谢产物对白囊耙齿菌产生抑制;木材接种试验结果表明,接种SF2菌株能显著减少白囊耙齿菌所致樟子松木材质量损失,减少率达46.43%。综上,本研究筛选鉴定的SF2菌株为长枝木霉,其对白腐真菌生长及其所致木材腐朽具有一定的防治效果,本研究为木材白腐病的生物防治奠定理论基础。

Interfacial processes and mechanisms of synergistic degradation of dichlorobiphenyl by white rot fungi and magnetite nanoparticles

The rapid increase in the artificial syntheses of organic pollutants has raised widespread concern.However,the mechanisms by which fungi degrade these new organic pollutants in the environment and adapt to environmental stressors remain unclear.In this study,Phanerochaete chrysosporium,a model white rot fungus,was used to explore the interfacial processes and mechanisms for synergistic degradation of 4,4′-dichlorobiphenyl(PCB15)with magnetite nanoparticles.The results showed that after 3 and 5 days of cultivation with Phanerochaete chrysosporium alone,the rates for PCB15 degradation were 32%and 65%,respectively,indicating that the white rot fungus itself was able to degrade the organic pollutant.Moreover,the addition of magnetite nanoparticles significantly enhanced the degradation of PCB15 by Phanerochaete chrysosporium.After cocultivation for 3 and 5 days,the rates for PCB15 degradation increased to 42%and 84%,respectively.Synchrotron radiation-based Fourier transform infrared spectromicroscopy(SR-FTIR)showed that the magnetite particles were tightly adhered to the fungal hyphae and were unevenly distributed on the hyphal surfaces.Furthermore,cocultivation of the fungus and magnetite nanoparticles significantly enhanced the nanozymatic activity of magnetite.A linear regression model provided a significantly negative correlation(r=−0.96,p<0.001)between the nanozymatic activity of the magnetite and the concentration ratio of the PCB15,supporting the hypothesis that white rot fungi degraded the PCB15 by enhancing the nanozyme activity of magnetite.High-resolution X-ray photoelectron spectroscopy(XPS)revealed that the nanozymatic activity of magnetite was mainly governed by oxygen vacancies on the mineral surfaces rather than the iron valence.Together,these findings increase our understanding of the powerful capabilities of fungi in terms of stress resistance and adaptation to extreme environments and provide new insights into fungal-mediated degradation of organic pollutants for soil remediation in contaminated sites.

白腐真菌Phanerochaete sordida对土壤中吡虫啉的降解研究

为探究白腐真菌对土壤中吡虫啉的降解性能,采用控制变量方法进行了吡虫啉的提取实验和降解实验。结果表明:吡虫啉最优的提取方法为利用甲醇进行超声20 min;在降解实验中,Phanerochaete sordida YK-624对土壤中吡虫啉有良好的降解效果。然而,添加适量碳源,并且增加培养天数都不能提高降解效果,而菌种添加量的增加对降解效果具有积极作用。本项研究初步探索了P.sordida YK-624对土壤中吡虫啉的高效降解条件,对实际吡虫啉污染土壤的白腐真菌修复工作具有重要的理论指导意义。

耐锑白腐真菌的筛选及其吸附特性的研究

随着我国锑相关产业的大规模发展,大量含锑化合物被排入到环境中,对生态环境造成了严重的威胁,如何处理锑污染也成为当今环境科学的研究热点。本研究从几种白腐真菌中筛选出较为耐锑的菌种作为吸附材料,并研究初始浓度、吸附时间及p H条件的改变对锑吸附性能的影响。实验结果表明,最耐锑的白腐真菌是黄孢原毛平革菌(Phanerochaete chrysosporium),在锑初始浓度为50 mg/L、pH=3条件下吸附12 h,对锑的吸附效果最好,吸附量最高达291.76 mg/g。

中国储木及建筑木材腐朽菌(Ⅰ)

本文首次系统报道了生长在中国原木、建筑物(包括房屋、桥梁、涵洞、栅栏等木质结构材)、坑木、枕木、矿柱、电杆、薪材等上的腐朽菌107种。其中24种引起木材褐色腐朽,83种引起白色腐朽。褐色腐朽的种类主要发生在针叶树木材上,白色腐朽的种类在针叶树和阔叶树木材上都常见。在针叶树原木上常见的木材腐朽菌有黄薄孔菌、红缘拟层孔菌、深褐褶菌、硫磺绚孔菌、冷杉附毛孔菌。在阔叶树原木上常见的有紫褐多孢孔菌、黑管孔菌、一色齿毛菌、红贝俄氏孔菌、硬毛粗毛盖孔菌、皮生锐孔菌、淡黄木层孔菌、鲜红密孔菌、淡黄裂孔菌、毛栓孔菌、锗栓孔菌和云芝栓孔菌等。这些种类来自作者长期的采集、记载和鉴定,全部标本保存在中国科学院沈阳应用生态研究所生物标本馆。

4种木材腐朽菌对白桦木材降解能力的比较

Four wood rot fungi were used to decay 300 mature trees of white birch in Liangshui experiment stations,and the mass loss of the samples was measured to study bio-degradability of the wood by the fungi. The decaying susceptible and resistant populations in 10 trees each with the highest and lowest mass loss were selected,in which some main chemical components in decayed and non-decayed wood such as lignin and cellulose and so on was tested. The result showed that the decomposing power of Coriolus versicolor to wood samples was better,and then were Fomes fomentarius,Irpex lacteus and Pholiota adiposa were poor. 1%NaOH extraction in decayed wood was significant higher than that in non-decayed control. Benzene-alcohol extraction in the wood decayed by Coriolus versicolor and Fomes fomentarius was significant higher than that in non-decayed control,but much lower than the control in the wood decayed by Irpex lacteus. The lignin decomposing rate by Irpex lacteus,Pholiota adipose and Fomes fomentarius were faster than the cellulose decomposing rate,the contrary result was achieved by Coriolus versicolor. This paper would provide some useful information in future study in the course and mechanism of wood decaying by rot fungi,and select engineering fungi for paper-making industry and pollution control.

6种木材白腐菌对山杨材木质素分解能力的研究

由于不同的木材腐朽菌的生理特性不同 ,所分泌的酶及酶的活性各不相同 ,因此 ,不同的腐朽菌分解木材的各种成分及相对速度就各不相同 ,而且对于木质纤维基质会有不同的中间代谢产物。本项研究选择了火木层孔菌 (Phelliusigniarius)及另外 5种木材分解能力较强的阔叶树上的白腐菌 :粗毛盖菌 (Funaliagallica)、三色革裥菌 (Lenzitestricolor)、冬拟多孔菌 (Polyporellusbrumalis)、偏肿拟栓菌 (Pseudotrametesgibbosa)和血红密孔菌 (Pyc noporussanguineus) ,研究了它们对山杨木材木质素的分解能力 ,测定了经 6种白腐菌分解一定时期的山杨木材木质素的含量 ,作为木材白腐菌对山杨木材木质素生物降解机制的初步研究 ,旨在为山杨木材生物制浆造纸提供应用基础理论研究 ,同时也可为木质素合理的生物转化为有用的化学品、生物漂白、酶处理防止机械浆的返黄、废水治理、纤维素酶解糖化的微生物前处理等提供相关的借鉴研究 ,以期在生产实践中减轻环境污染并充分利用木质素资源。在无菌的条件下 ,将山杨木片样品分别放入以上 6种白腐菌的平板培养基中受菌侵染 ,一定时间后取出 ,去除木片表面的菌丝体 ,然后分别测定未腐朽材和受菌侵染 4 0d、6 0d、80d和 12 0d时木片样品中木质素的含量 ,分析

6种白腐菌腐朽后的山杨木材和木质素官能团变化的红外光谱分析

选择火木层孔菌及 5种木材降解能力较强的阔叶树上的白腐菌 :粗毛盖菌、偏肿拟栓菌、三色革裥菌、冬拟多孔菌和血红密孔菌 ,采用国内外红外光谱分析的标准方法 ,用傅里叶红外光谱仪测定未腐朽材木粉和受 6种白腐菌腐朽 12 0d后的腐朽材木粉试样的红外光谱图。刮取未腐朽的山杨木材样品和受 6种白腐菌腐朽 12 0d时的山杨木材样品表层少许 ,在干燥条件下 ,分别放入KBr中 ,磨细 ,压片 ,然后在FTIR光谱仪上进行测定 ,得到经 6种白腐菌降解 12 0d后的木材木粉和未腐朽材木粉其木材和木质素官能团谱峰位置和谱峰相对吸收强度的振动变化状况 ,进而分析腐朽后的山杨木材和木质素官能团的变化情况 ,以作为木材白腐菌对山杨材生物降解机制的进一步研究。结果表明 ,受 6种白腐菌腐朽后的山杨木材和木质素官能团都受到一定程度的降解 ,但各自的变化情况有所不同。对木质素的降解主要是存在于侧链上 ,虽然苯环骨架变化不明显 ,但木质素苯环间的羰基、CH2 结构、紫丁香基和愈疮木基等侧链已部分被降解。从各吸收峰相对吸收强度的变化大小来看 ,血红密孔菌、冬拟多孔菌。