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.

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.

Relative efficacy of heartwood extracts and proprietory wood preservatives as wood protectants

The relative potentials of either heartwood extracts (air dry extracts in 60 percent methanol) of very durable woods (Afzelia africana J.E. Smith; Erythrophleum suaveolens (Guill & Perr.) Brenam. Syn. E guinensis G.Don. or Milicia excelsa (Welw) C.C. Berg. Syn. Chlorophora excelsa (Welw) Benth.) or any of two proprietary wood preservatives (AWPA type 揅? Chromated Copper Arsenate (CCA) or 5 percent solution of AWPA Standard Designation P ??type 揅? Pentanchlorophenol (Penta) in light oil solvent) to suppress attack on pressure treated Antiaris toxicaria Lesch Sapwood by either any of three species of decaying fungi (Coridopsis Polyzona Klotzch; Lenzites trabea; or Trametes cingulata Fr.) under soil block exposure conditions were investigated and threshold values determined. Extract/preservative dosages were either 8.009; 24.778; 48.056; 96.111 or 144.167 kg穖-3 (0.5; 1.5; 3.0; 6.0 or 9.0 1b/ft3). Exposure was for either 14 or 28 weeks and in accordance with ASTM D1413 72 Provisions. Conclusions reached were that at threshold values the ability of either any of the heartwood extracts or proprietary wood preservatives to suppress attack under conditions in this study was significant at 0.01. Relative efficacy of those biocides was dependent on fungal species. Neither any of the heartwood extracts nor any of the proprietary wood preservatives (except in the case of Trametes cingulata attack on CCA treated wood at highest retention level) was able to confer 搗ery durable?rating on treated wood. Possible reasons for the reduced relative durability of extracts visa vis native heartwood were advanced. At the highest retention level (144.167 kg穖-3) there was no significant difference (at 0.05 level) between efficacy of each of the heartwood extracts and any of the proprietary wood preservatives (CCA or Penta).

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.

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.

Inhibitory Effect of N,N-Dimethylhexadecylamine on the Growth of White-Rot Fungus Trametes versicolor(L.)in Wood

Wood is an organic material that is a source of carbon of organisms called Wood-decay fungi,and to preserve the wood,various toxic compounds to man and the environment have been used.To analyze the effect of N,NDimethylhexadecylamine(DMHDA)on wood attacked by the rotting fungus Trametes versicolor L.We used an in vitro system to expose the fungus T.versicolor to different concentrations of the DMHDA(50,150 and 450µM).We quantified the diameter of mycelial growth and laccase activity,also,under these experimental conditions we studied morphological details of the organisms using different scanning equipment including scanning electron microscopy.The growth of T.versicolor exposed to DMHDA for 60 days,showed a concentration-dependent dose behavior,also,the electron microscopy analysis revealed that the morphology and mycelial density was affected by the DMHDA,showing a formation of atypical morphological and thickener folds.Finally,the pieces of wood treated with DMHDA and exposed to the fungus had a lower mass loss,after a period of 60 days of exposure,the values obtained were 0.7,1.0 and 0.5 g of mass lost for the control,LoC and LoDMHDA treatments respectively.Wood-rot fungi have represented economic losses worldwide,the strategies used have been supported by toxic compounds for the environment.The DMHDA both in the Petri dish system and as a wood preservative was shown to significantly inhibit the growth of T.versicolor.

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.

黄肉猕猴桃‘金实4号’果实采后蒂腐病病原菌的分离及鉴定

以猕猴桃新品种‘金实4号’采后病果为试材,取果实果蒂病组织分离腐烂病病原菌,按照柯赫氏法则确定分离病株的致病性,同时采用形态学结合分子生物学鉴定技术对病原菌种类进行鉴定,明确黄肉猕猴桃果实采后贮藏期引起腐烂的病菌种类,以期为黄肉猕猴桃采后腐烂病防治研究提供参考依据。结果表明:共有8种软腐病病原菌被鉴定,分别是拟茎点霉菌(Phomopsis sp.)、间座壳菌(Diaporthe cotoneastri)、小孢拟盘多毛孢(Pestalotiopsis microspora)、灰葡萄孢(Botrytis cinerea)、新壳梭孢(Neofusicoccum parvum)、链格孢(Alternaria sp.)、镰刀菌(Fusarium sp.)、葡萄座腔菌(Botryosphaeria dothidea)。

草莓连作根腐病原菌及根际真菌群落变化多样性研究

草莓是一种兼具营养和经济价值的水果,草莓连年栽培导致连作障碍发生严重,发病率逐渐增加,严重影响了草莓的产量。从连作3年且患有根腐病的草莓根际土壤中分离出病原菌,经鉴定分别为Fusarium pseudocircinatum、Fusarium solani、Fusarium luffae、Aspergillus westerdijkiae、Cladosporium oxysporum、Ectophoma multirostrata、Neopestalotiopsis rosae和Neocosmospora rubicola。进一步对连作前后草莓根际土壤真菌变化进行分析,结果表明,连作后真菌总数量下降,在属水平上,Pulvinula、Aspergillus、Acremonium、Funneliformis、unclassified_Cercozoa和unclassified_Pezizaceae等真菌的相对丰度均显著或极显著增加,unclassified_Hypocreales、Mortierella和Rhizophlyctis等真菌的相对丰度均显著或极显著降低。对连作后土壤的理化性质进行检测,结果表明,有机质含量极显著降低,全磷、硝态氮含量极显著增加,pH值显著增加。这说明土壤理化性质的改变和优势菌种的更替都是导致草莓连作障碍发生的原因,可为防治草莓根腐病和连作障碍提供科学依据。

绿木霉NY45对木材腐朽菌的抑制作用及机理研究

为探索木材生物防腐,以绿木霉(Trichoderma virens,NY45株系)为对象,研究其对木材白腐菌彩绒栓菌(Trametes versicolor,Tv)及褐腐菌密粘褶菌(Gloeophyllum trabeum,Gt)的抑制效果并探索抑制机理。结果表明:NY45对两种腐朽菌均有明显的抑制作用,经NY45孢子液处理的毛白杨木材,其耐腐等级从IV级(不耐腐)提升到I级(强耐腐);NY45生长速度远快于木材腐朽菌,可以迅速抢占空间和竞争营养,并能寄生、覆盖、消解木材腐朽菌菌丝,其易挥发性物质对Tv和Gt抑制率分别为18.55%和45.69%,难挥发性代谢产物对两种木材腐朽菌的抑制率均超过90%。NY45有潜力作为木材腐朽生物防治菌进一步开发利用。

新疆甜瓜采后致腐菌及拮抗菌的分离、筛选与鉴定

[目的]对甜瓜采后主要致腐微生物进行分离鉴定,并筛选出防腐效果最佳的拮抗菌株,丰富甜瓜采后保鲜拮抗菌资源。[方法]利用组织块分离法在腐烂的甜瓜果实中分离致腐菌,采用梯度稀释法从甜瓜种植地土壤分离拮抗菌,通过平板对峙法筛选出拮抗作用较强的生防菌,并通过形态学观察、生理生化测定、生物学鉴定确定其种属,测定拮抗菌对菌丝生长及分生孢子萌发的作用,明确拮抗菌对致腐菌的防治效果。[结果]本研究分离出1株主要病原菌CH-3,通过对ITS、tef和tub基因序列进行BLAST比对及系统发育分析,结合菌落形态特征观察,病原菌CH-3鉴定为尖孢镰刀菌。从甜瓜种植地土壤中分离得到67株细菌,通过拮抗试验得到3株抑菌活性很强的拮抗菌,分别为BG-1、BG-2和BG-3,选取抑菌效果更好的BG-2作为供试菌株,结合生理生化测定、菌落和菌体形态特征观察及16S rDNA、gyrB和rpoB基因序列分析结果,明确拮抗菌BG-2为贝莱斯芽孢杆菌。致病性测定结果表明,致腐菌CH-3对甜瓜有致病性,拮抗菌BG-2对甜瓜致腐菌尖孢镰刀菌CH-3孢子萌发、菌丝生长的相对抑制率分别为90.00%、60.11%。[结论]获得1株拮抗效果最佳的拮抗菌BG-2,鉴定为贝莱斯芽孢杆菌,分离到1株甜瓜主要致腐菌CH-3,鉴定为尖孢镰刀菌。贝莱斯芽孢杆菌BG-2对尖孢镰刀菌CH-3有较强的拮抗作用,致腐菌CH-3对甜瓜有致病性,拮抗菌BG-2能有效抑制甜瓜致腐菌尖孢镰刀菌CH-3孢子萌发和菌丝生长,且拮抗菌浓度越高对孢子萌发的抑制效果越好,在甜瓜采后贮藏及生物保鲜中具有潜在的应用价值。

健康与罹病三七内生真菌的分离鉴定及其群落特征差异分析

[目的]本文旨在探究健康与罹患根腐病三七内生真菌群落特征差异及在不同植株部位的分布特征与随生长年限的变化规律。[方法]选取1年、2年生健康与罹患根腐病的三七植株,采用组织分离法对其根、茎部位的内生真菌进行分离,基于形态特征和ITS序列分析对分离得到的菌株进行分类鉴定,并对内生真菌群落组成及多样性特征进行分析。[结果]共分离获得966株内生真菌,经鉴定隶属于3门、5纲、14目、25科、31属。从菌株分离数及分离率看:罹病植株>健康植株,2年生>1年生,根部>茎部。健康和罹病三七的可培养内生真菌组成存在明显差异,其中曲霉属、耙齿菌属、毛壳属和青霉属在健康三七内生真菌群落中占主导,而镰刀菌属、曲霉属、篮状菌属、毛壳属和木霉属是罹病三七内生真菌的优势属。植株部位对三七内生真菌群落组成具有明显影响,其中罹病三七根部镰刀菌属的分离频率高达52%,显著高于其茎部的11.2%,且在罹病三七根部大量分离到木霉属和篮状菌属等有益真菌,其分离频率分别为11.0%和14.5%,而三七茎部内生真菌群落多样性、丰富度和均匀度均高于根部。此外,随着生长年限的增加,三七内生真菌群落的发育更加完善,健康和罹病三七内生真菌群落组成及多样性特征也随之变化,其中尖孢镰刀菌和腐皮镰刀菌在罹病三七植株中的分离频率大幅增加,达到14.5%和32.9%。健康三七内生真菌多样性、丰富度和均匀度随生长年限增加逐渐上升,而罹病三七内生真菌多样性和均匀度逐渐降低。[结论]三七植株内生真菌多样性丰富,健康和罹病三七可培养内生真菌定殖数量及群落组成具有显著差异,且植株部位与生长年限均对三七可培养内生真菌群落特征具有显著影响。

白腐真菌预处理农作物秸秆的研究进展

农作物秸秆资源丰富,对反刍动物来说是一种低成本的可再生粗饲料来源,但秸秆在饲喂动物时其高含量的木质纤维素限制了反刍动物瘤胃微生物的作用,以致不能被有效利用,在实际生产中缺乏理想的处理方式,没有开发出其应有的营养价值。白腐真菌预处理可以提高农作物秸秆的消化率,该菌能够在营养价值相对较低的秸秆上生长,可以通过分泌1种或多种木质纤维素降解酶以及自由基等,将木质纤维素分解为能够被反刍动物消化的糖类等小分子化合物。本文就农作物秸秆的饲料化应用现状、处理方式展开讨论,并对白腐真菌处理木质纤维素的作用机制和影响因素以及在动物生产上的应用进行了综述,旨在为提高农作物秸秆的营养价值提供理论参考。

镉胁迫下复合菌剂对大豆的光合修复及其固定化效果的探究

镉(cadmium,Cd)作为对大豆等粮食类作物毒害最大的重金属之一,不仅会抑制植物生长发育,还会损害其光合系统致使光合速率下降。目前对于镉修复技术的探讨多集中于施加植物激素、改变种植模式等方向,微生物与植物互作的研究仍有待探索。本研究为探究复合白腐真菌(White rot fungi)对镉污染的修复效果和固定化技术的实际应用价值,以4种白腐真菌和大豆作为供试材料,制备固态菌剂并对大豆设置土培处理,且模拟镉污染土壤的浓度为0、50、100 mg L^(-1),对应每个浓度分别进行3种处理(CK组-不做处理、EG1组-加入游离菌株、EG2组-加入固态菌剂),研究混菌发酵与固定化技术对菌株吸附效能的影响,同时探明镉毒害、固定化菌球以及大豆植株三者间的关联性。结果表明:(1)除黄孢原毛平革菌外,其余3种菌株兼容性良好。(2)当混菌菌株组别为凤尾:云芝等于1∶1时,处理浓度为50 mg L^(-1)的镉溶液时可达到87.33%的吸附率。(3)为延长混合菌株的使用时效,提高吸附效果,以海藻酸钠(SA)质量浓度为10 g L^(-1)、生物炭(BC)质量浓度为15 g L^(-1)、加菌量为2%制得的PVA固定化小球,在加入适量添加剂后96 h吸附率可达(95.12±1.68)%。(4)将固定化混菌菌剂施加入模拟镉污染土壤后,大豆的各项生长和光合指标受到的抑制作用均得到缓释,其中Fo的最大降幅为42.5%,Fv/Fm最大增幅为17.2%。(5)大豆的抗氧化系统在菌剂处理14 d时得到增强,CK组中SOD、POD、CAT 3种酶最高活性均得以提升,分别为27.34%、12.41%、13.58%;此外,Pro及MDA含量分别呈上升和下降趋势,共同表现出植物抗性的提高。综上,镉胁迫下植株的PSII光化学反应中心受到抑制,混合菌株固定化与单个或游离状态的菌株相比吸附效率更高,施加固态菌剂后可有效开启大豆的光保护机制,产生渗透调节物质,同时激活抗氧化系统,保证了大豆体内稳定的氧化还原环境以应对镉胁迫。

响应面法优化白腐菌Pleurotus ostreatus降解六氯苯

采用响应面法优化白腐菌侧耳属菌株(Pleurotus ostreatus)降解六氯苯(HCB)的条件。结果表明,对HCB降解率影响显著性较大的是摇床转速和pH。在摇床转速125r/min、pH为7.0、培养温度为28℃、HCB初始质量浓度为10mg/L、接种量为5%(体积分数)、培养时间为2d的优化条件下,HCB降解率和降解速率分别为92.73%和2.318mg/(L.d)。

Pleurotus ostreatus BP连续开放预处理玉米秸秆的研究

通过筛选开放性菌株以及对开放状态下玉米秸秆糖化率随预处理时间变化规律的研究,建立了菌株Pleurotus ostreatus BP连续开放预处理玉米秸秆体系,并进一步对该体系的稳定性进行了评价。从14株自腐菌中筛选出5株在秸秆上萌发时间短、生长速率快的菌株,其中只有P.ostreatus BP能在玉米秸秆上开放培养,预处理15 d时糖化率最高。由此建立了P.ostreatus BP开放预处理玉米秸秆15 d的连续体系并预处理5批。结果表明,前3批的预处理效果较稳定,糖化率均比对照提高了20%以上。在连续的第4、5批次中,糖化率提高很少,这主要是由于开放体系中的杂菌数量急剧增多造成的。

白腐菌Pleurotus ostreatus漆酶的生产及其最佳诱导条件

漆酶可催化酚类化合物和芳香胺的氧化,在小分子介体物质存在下,漆酶氧化范围可进一步扩大。白腐菌Pleurotusostreatus3.42产漆酶能力强,可成为工业用漆酶的重要生产者。研究结果表明,其在静止培养条件下,菌体生长及产漆酶能力都优于摇床培养,同时限氮培养也利于漆酶的生产。在所选的碳氮源中,纤维素和酪蛋白为最佳碳氮源。在诱导剂中ABTS诱导效果最佳,添加后漆酶酶活可达1000U／mL。

马尾松木材防霉防蓝变研究进展

马尾松(Pinus massoniana Lamb.)是我国南方分布最广,最主要的用材树种之一,生长速度快、适应能力强、木材力学性能好,被广泛应用于建筑、造纸、装饰、家具、交通等行业。然而,由于其内部含有许多营养物质,易受到霉菌和蓝变菌的侵害。本文重点对国内外传统和新型的马尾松木材防霉防蓝变药剂和处理方法进行了阐述,同时对存在的问题进行了分析,并对研究方向进行了展望,旨在为今后开发新型防霉防蓝变药剂和方法提供理论支持。

鄂西北烟草根腐病病原菌的分离及鉴定

镰刀菌属引起的根腐病是烟草的重要病害,根腐病危害严重可导致烟草产品质量和产量出现重大损失。为明确鄂西北烟草根腐病病原,从湖北十堰烟区采集典型症状标本分离病原菌,对其进行了形态学和分子生物学鉴定,结合基因系统发育学分析和致病性验证,确定鄂西北烟草根腐病的病原为尖孢镰刀菌、腐皮镰刀菌、木贼镰刀菌和接骨木镰刀菌。