Effects of Material Physical Properties on White-rot Fungi Mycelial Growth

[ Objective] The research aimed to study effects of material physical properties on white-rot fungi mycelial growth and provide theoretical basis for further expanding the application range of white-rot fungi. [ Method Four common species of white-rot fungi were cultivated by wood meal fowl dung mixture in test tube and culture dishes. The relationship between physical properties of culture material and the growth of these mycelials were studied. [Result] The results showed the water retention capacity of culture material was decreased with the increasing of its grain size and porosity, but the decrease of its specific gravity reduced the material water retention. And the dehydration rate of medium prepared with these materials at the same moisture conditions tended to increase. These physical properties of material, such as grain size, specific gravity, porosity, water retention and water drainage, influenced the growth of white-rot fungi mycelial by affecting the moisture and ventilation condition of media. The results hinted that above material physical properties had feedback effects on the growth of white-rot fungi mycelia. [ Conclution] Physical properties of culture material have significant effects on the growth of white-rot fungi mycelial.

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.

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.

多环芳烃(PAHs)污染土壤中接种平滑白蛋巢菌对蒿柳光合作用的影响

【目的】虽然已有研究表明植物-白腐真菌联合修复是一种更高效的多环芳烃(PAHs)污染土壤修复策略,但由于该策略的作用机理尚不清楚,其在土壤修复实践中的应用前景仍存有疑问。光合作用不仅是植物生长发育的基础,也影响根系分泌物的释放水平,进而影响根际微生物的生长和土壤中PAHs的降解。基于此,我们研究了PAHs污染土壤中接种白腐真菌对植物光合作用的影响。【方法】在温室中设置了PAHs污染土壤的盆栽修复实验,以蒿柳做为植物修复材料,选取光合色素含量、气体交换参数的光响应曲线和叶绿素荧光参数做为蒿柳的光合生理指标,探究了PAHs污染土壤中接种白腐真菌对蒿柳光合作用的影响。【结果】PAHs污染土壤中接种白腐真菌对蒿柳光合色素含量、净光合速率(Pn)、蒸腾速率(Tr)、最大光化学效率(Fv/Fm)、光系统Ⅱ(PSⅡ)潜在活性(Fv/F0)等指标均有积极的促进作用,但降低了叶片的气孔导度(Gs)、胞间CO2浓度(Ci)、非光化学淬灭(NPQ)和光化学淬灭(qP)参数。不同的接种方法能改变Gs、Tr的光响应曲线的变化趋势。此外蒿柳-白腐真菌联合修复显著提高了土壤菲(PHE)、芘(PYR)的去除率。【结论】PAHs污染土壤中,白腐真菌能提高蒿柳的光合能力和蒸腾效率,促进土壤PHE和PYR的去除,这对揭示植物-白腐真菌联合修复的作用机理有重要意义。

Cooperation between ligninolytic enzymes produced by superior mixed flora

Since the ability to degrade lignin with one kind of white-rot fungi or bacteria was very limited, superior mixed flora's ability to degrade lignin was investigated by an orthogonal experiment in this paper. The results showed that superior mixed flora reinforced the ability to degrade lignin, the degradation rates of both sample 9 and 10 were beyond 80% on the day 9 The cooperation between lignin peroxidase(LiP), Mn-dependent peroxidase(MnP) and laccase (Lac) for lignin degradation was also studied. By examining the activities of three enzymes produced by superior mixed flora, it was found that Lac was a key enzyme in the process of biological degradation of lignin but Lip was not; the enzyme activity ratios of Lac/MnP and Lac/LiP were significantly correlative with the degradation rate of lignin at the 0 01 level; and the ratio of MnP/LiP was an important factor affecting the degradation rate of lignin.

Effect of Soya Lecithin on Solubilization and Biodegradation of Pentachlorophenol by <i>Anthracophyllum discolor</i>

The effect of soya lecithin (SL) on solubilization and biodegradation of pentachlorophenol (PCP) by Anthracophyllum discolor was evaluated. Besides, the PCP effect on critical micelle concentration (CMC) of SL and the effect of PCP and SL on the ligninolytic activity of A. discolor were evaluated. The PCP solubilization test was performed for 100, 200 and 400 mg·L-1 with SL solution varying concentrations of ranging from 0 to 0.9 g·L-1. The effect of PCP (5 to 20 mg·L-1) on CMC of SL by conductivity was evaluated. The effect of SL (0 to 0.9 g·L-1) on biodegradation of PCP (21.4 mg·L-1) in modified Kirk medium was studied. The results showed that SL addition enhanced PCP solubility in water. The solubilities of 100, 200 and 400 mg·L-1 of PCP were about 4.2, 5.0 and 2.5 times higher than their solubility in pure water when the system was added with 0.9 g·L-1 of SL. We found that the increase in PCP concentration caused a decrease in the CMC value. In the biodegradation assay, in liquid medium supplemented with 0.9 g·L-1 of SL, the 94.4% of PCP was biodegraded after 26 days of incubation. In contrast, in the control assay (without SL), the 76.5% of PCP was removed. The PCP degradation was confirmed by the presence of its metabolites. During biodegradation assay, A. discolor mainly produced manganese peroxidase reaching a maximum of 96.8 U·g-1 (dw) when the culture medium was added with 0.6 g·L-1 of SL. These results show that SL can be applied to increasing the bioavailability and biodegradation of PCP.

Reducing sugars production from pretreated rapeseed straw

Lignocellulosic biomass, being treated only with ammonia, treated with ammonia and then autoclaved, and treated with white-rot fungi after being mechanically chipped, were carried out to access the effects of lignocellulose degradation by white-rot fimgi cultured on rapeseed straw. Fourier transform infrared spectroscopic analysis was used to show that the white-rot fungus Bjerkandera sp. strain increase the susceptibility of straw to enzymatic saccharification by modifying the lignin component, revealing the effect of these pretreatments on enzymatic saccharification. Reducing sugar production from straws pretreated by ammonia/mechanical chipping/fungi degradation was 29.80% higher than the samples treated with ammonia/autoclaving, indicating an effective degradation of phenolic compounds. After ammonia pretreatment 41% of the straw was converted to RS （reducing sugars） （glucose 50%）. After 5 weeks pretreatment with the white-rot fungus, 54.8% of rapeseed straw was further converted to RS, 74% of which was glucose; while only 12% of the control straw was converted （glucose 42%）. The white-rot fungus Bjerkandera sp. strain degraded rapeseed straw preferentially at the early stage （before 20 d）, and the degradation selectivity was 0.181 1 （cellulose）, 0.364 1 （hemicellulose）, and 0.454 8 （lignin）, suggesting that removal of the phenolic barriers enhanced reducing sugar yield, and the efficiency of fungal pretreatment was comparable with that after alkali treatment, resulting a higher proportion of glucose in the hydrolysates.

Mycoremediation of Petroleum： A Literature Review

Mycoremediation is a cleanup technique within the larger field of bioremediation. In this literature review, the history, species and methods of mycoremediation are investigated. The literature suggests that many fungi have the ability to degrade a wide variety of pollutants. The functional group white-rot fungi have previously been shown to biodegrade petroleum using extracellular enzymes, and have received much popular attention. For this reason, the white-rot basidiomycete Pleurotus ostreatus is the focus of this review. The extracellular enzymes that make mycoremediation possible, fungi＇s synergy with bacteria, and the effects of temperature are discussed. The authors compare mycoremediation to other bioremediation methods. The authors conclude that environmental factors such as aeration, soil structure, nutrient level and especially temperature, may have stronger effects on petroleum loss than inoculation with white-rot fungi. For volatile pollutants such as diesel, the use of fungal inoculation may be economical only when fungal spawn compost is abundantly available. Composting also may be an inexpensive method to increase temperature, enhancing remediation of hydrocarbons.

Species diversity,taxonomy and phylogeny of Polyporaceae(Basidiomycota)in China

Polyporaceae is one of the most important families of Basidiomycota.Investigations on the species diversity,taxonomy and phylogeny of Polyporaceae in China are carried out.So far 217 species belonging to 42 genera are reported from China.Two new genera:Amylosporia gen.nov.and Murinicarpus gen.nov.,twelve new species:Coriolopsis dendriformis sp.nov.,C.hainanensis sp.nov.,Funalia cystidiata sp.nov.,Haploporus microsporus sp.nov.,Perenniporia citrinoalba sp.nov.,P.yinggelingensis sp.nov.,Picipes hainanensis sp.nov.,P.jiajinensis sp.nov.,P.pseudovarius sp.nov.,Trametes duplexa sp.nov.,T.ellipsoidea sp.nov.and T.stiptica sp.nov.,and six new combinations,Amylosporia hattorii comb.nov.,Hornodermoporus latissimus comb.nov.,Murinicarpus subadustus comb.nov.,Picipes pumilus comb.nov.,Vanderbylia delavayi comb.nov.and Vanderbylia robiniophila comb.nov.,are proposed.All the species are described based on the Chinese collections.Keys to genera of Polyporaceae occurring in China and keys to species of each genus are provided.This monograph provides a revised classification of Polyporaceae in China according to the modern taxonomy.The phylogeny of Polyporaceae from China are reconstructed based on DNA sequences of multiple loci including the internal transcribed spacer(ITS)regions,the large subunit nuclear ribosomal RNA gene(nLSU),the small subunit nuclear ribosomal RNA gene(nSSU),the small subunit mitochondrial rRNA gene sequences(mtSSU),the translation elongation factor 1-αgene(TEF1),theβ-tubulin gene(TBB1),the RNA polymerase II largest subunit(RPB1)and second largest subunit(RPB2)genes.In addition,full morphological descriptions,illustrations,color photographs,taxonomic notes,ecology and all the available sequences of Polyporaceae species found from China are provided.

Comparing the removal of polycyclic aromatic hydrocarbons in soil after different bioremediation approaches in relation to the extracellular enzyme activities

A 120-day experiment was conducted to compare the removal of polycyclic aromatic hydrocarbons(PAHs) from agricultural soil after natural attenuation(NA), phytoremediation(P), mycoremediation(M), and plant-assisted mycoremediation(PAM) approaches in relation to the extracellular enzyme activities in soil. The NA treatment removed the total soil PAH content negligibly. The P treatment using maize(Zea mays) enhanced only the removal of low and medium molecular PAHs. The Pleurotus ostreatus cultivated on 30–50 mm wood chip substrate used in M treatment was the most successful in the removal of majority PAHs. Therefore,significantly(p < 0.05) highest total PAH removal by 541.4 μg/kg dw(dry weight)(36%) from all tested M treatments was observed. When using the same fungal substrate together with maize in PAM treatment, the total PAH removal was not statistically different from the previous M treatment. However, the maize-assisted mycoremediation treatment significantly boosted fungal biomass, microbial and manganese peroxidase activity in soil which strongly correlated with the removal of total PAHs. The higher PAH removal in that PAM treatment could be reflected in the following post-harvest time. Our suggested M and PAM approaches could be promising in situ bioremediation strategies for PAH-contaminated soils.

A comparison of lignin-degrading enzyme activities in forest floor layers across a global climatic gradient

Rapid litter turnover in tropical forests and during summer seasons might be due to increases in ligninolytic enzyme activities during warmer periods.We compared ligninolytic enzyme activity[lignin peroxidase(LiP),manganese peroxidase(MnP),and laccase(Lac)]in the organic layers of forest soils across a global climate gradient.As expected,MnP activities in fresh litter layers increased with increasing air temperature.Litter Mn/lignin ratios correlate positively with MnP activity and more rapid litter turnover in warmer climates.In contrast,LiP and Lac activities are regulated by site-specific conditions.Lac activity is commonly observed in less acidic fresh litter layers,while LiP activity localizes in acidified and lignin-rich deeper organic layers.The widespread occurrence of MnP and an increase in MnP activities in warmer climates support efficient lignin degradation in the tropics and during summer seasons.High Mn/lignin ratios in fresh litter could be an indicator of lignin degradability by MnPproducing fungi across global climate gradients.