Toxicity and bioaccumulation of heavy metals in Phanerochaete chrysosporium

The responses of the growth and metabolism activity of Phanerochaete chrysosporium （P. chrysosporium） to cadmium （Cd）, lead （Pb） and their combined pollution stress, were investigated in plate and liquid culture conditions. The diameter of colony, biomass ofP. chrysosporium, ligninolytic enzyme activities and bioaccumulation quantity of heavy metals were detected. The results indicated that Cd was more toxic than Pb to P. chrysosporium and the toxicity of Cd and Pb to P. chrysosporium was further strengthened under Cd＋Pb combined pollution in different culture conditions. Heavy metals Cd and Pb had indirect influence on the production of ligninolytic enzymes by directly affecting the fungal growth and metabolic activity, and by another way in liquid culture. In addition, the results provided an evidence of the accumulation of Cd and Pb on the mycelia ofP. chrysosporium.

Influence of Phanerochaete chrysosporium on degradation and preg-robbing capacity of activated carbon

The effect of Phanerochaete chrysosporium on degradation and preg-robbing capacity of activated carbon,which was used as a substitute of carbonaceous matter in carbonaceous gold ores,was studied.After 14 d treatment with Phanerochaete chrysosporium,the degradation rate of activated carbon reached 27.59%.The XRD and FTIR analyses indicate that Phanerochaete chrysosporium can distort the micro-crystalline structure of activated carbon,increase the number of oxygen-containing groups and aliphatics and make the aromatic structures be oxidized and exfoliated.The gold-adsorption tests show that Phanerochaete chrysosporium can reduce the preg-robbing capacity of activated carbon by 12.88%.This indicates that Phanerochaete chrysosporium is an available microorganism,and it can be employed to reduce the preg-robbing capacity of carbonaceous matter and improve the gold leaching rate.The combined effect of passivation,alkalization and oxidation of biological enzymes-free radicals of Phanerochaete chrysosporium on carbonaceous matter was also discussed.

Effect of nitrogen concentration in culture mediums on growth and enzyme production of Phanerochaete chrysosporium

Effect of different nitrogen concentration in the mediums on growth and enzyme production of Phanerochaete chrysosporium was studied when glucose concentration was 10 g/L. The results showed that the medium contained 0.8 g/L ammonium tartrate is the best. It not only supply abundant nutrients for the growth of Phanerochaete chrysosporium, which make mycelia the best grow compared with the other medium, but also produce higher manganese-dependent peroxidase(Mnp) and laccase(Lac) activity. In addition, it is observed that the variation of mycelia surface is related to ligninolytic enzyme secreted by Phanerochaete chrysosporium. When the surface of mycelium pellets appeared burs, it predicts secondary metabolism begin. This experimentation demonstrated that when the ratio of carbon and nitrogen in nitrogen limited medium is equal to 100∶8, growth and enzyme production of Phanerochaete chrysosporium is the best, it could achieve the maximum Mnp and Lac activity.

Polycyclic aromatic hydrocarbon biodegradation and extracellular enzyme secretion in agitated and stationary cultures of Phanerochaete chrysosporium

The extracellular enzyme secretion and biodegradation of polycyclic aromatic hydrocarbons （PAHs） were studied in agitated and shallow stationary liquid cultures of Phanerochaete chrysosporium. Veratryl alcohol and Tween80 were added to cultures as lignin peroxidase （LIP） and manganese peroxidase （MnP） inducer, respectively. Shallow stationary cultures were suitable for the production of enzyme, whereas agitated cultures enhanced overall biodegradation by facilitating interphase mass transfer of PAHs into aqueous phases. The use of a LiP stimulator, veratryl alcohol, did not increase PAH degradation but significantly enhanced LiP activity. In contrast, Tween80 increased both MnP secretion and PAH degradation in shallow stationary cultures. On the other hand, high PAH degradation was observed in agitated cultures in the absence of detectable LiP and MnP activities. The results suggested that extracellular peroxidase activities are not directly related to the PAH degradation, and the increased solubility rather than enzyme activity may be more important in the promotion of PAH degradation.

Biodegradation of Gaseous Chlorobenzene by White-rot Fungus Phanerochaete chrysosporium

Objective To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene. Methods Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amount of chlorobenzene was injected into the headspace of the bottles under different conditions. At a certain interval, the concentrations in the headspace were analyzed to evaluate the degradation of chlorobenzene by P. chrysosporium. Results The degradation effects of P. chrysosporium on chlorobenzene under different conditions were investigated. The difference in the optimum temperature for the growth of the fungi and chlorobenzene degradation was observed. The data indicated that a lower temperature （28℃） would promote the degradation of chlorobenzene than the optimum temperature for the growth of the fungi （37℃）. A low nitrogen source concentration （30 mg N/L） had a better effect on degrading chlorobenzene than a high nitrogen source concentration （higher than 100 mg N/L）. A high initial concentration （over 1100 mg/m3） of chlorobenzene showed an inhibiting effect on degradation by P chrysosporium. A maximum removal efficiency of 95% was achieved at the initial concentration of 550 mg/m3. Conclusion P. chrysosporium has a rather good ability to remove gaseous chlorobeuzene. A low nitrogen source concentration and a low temperature promote the removal of chlorobenzene by P. chrysosporium. However, a high initial chlorobenzene concentration can inhibit chlorobenzene degradation.

Manganese peroxidase production from cassava residue by Phanerochaete chrysosporium in solid state fermentation and its decolorization of indigo carmine

Bioconversion of lignocellulosic wastes to higher value products through fungal fermentation has economic and ecological benefits. In this study, to develop an effective strategy for production of manganese peroxidase(Mn P)from cassava residue by Phanerochaete chrysosporium in solid state fermentation, the stimulators of Mn P production were screened and their concentrations were optimized by one-at-a-time experiment and Box–Behnken design. The maximum Mn P activity of 186.38 nkat·g-1dry mass of the sample was achieved after 6 days of fermentation with the supplement of 79.5 mmol·L-1·kg-1acetic acid, 3.21 ml·kg-1soybean oil, and 28.5 g·kg-1alkaline lignin, indicating that cassava residue is a promising substrate for Mn P production in solid state fermentation. Meanwhile, in vitro decolorization of indigo carmine by the crude Mn P was also carried out, attaining the ratio of 90.18% after 6 h of incubation. An oxidative mechanism of indigo carmine decolorization by Mn P was proposed based on the analysis of intermediate metabolites with ultra-high performance liquid chromatography and gas chromatography tandem mass spectrometry. Using the crude Mn P produced from cassava residue for indigo carmine decolorization gives an effective approach to treat dyeing effluents.

Bio-dissolution of pyrite by Phanerochaete chrysosporium

The dissolution of pyrite was studied with Phanerochaete chrysosporium(P.chrysosporium).This fungus resulted in the dissolution of 18%iron and 33%sulfur.The oxidization layer was formed on the pyrite surface,which probably consisted of iron oxide,iron oxy-hydroxide,iron sulfate,elemental sulfur and mycelia.The electrochemical characteristics of pyrite were studied in the systems without and with P.chrysosporium.P.chrysosporium could accelerate the dissolution of pyrite by decreasing pitting potential and polarization resistance plus improving polarization current,corrosion potential and corrosion current density.The dissolution of pyrite is the combined effect of enzymes,hydrogen peroxide,ferric iron and organic acids.Enzymes attack the chemical bonds by free radicals.Organic acids dissolve pyrite by acidolysis and complexolysis.Enzymes and hydrogen peroxide play an essential role in this process.

Experimental research on Phanerochaete chrysosporium as coal microbial flocculant

The flocculation effect of the Phanerochaete chrysosporium on the coal slurry were studied by orthogonal experimental method in this study.The results of research show that the P.chrysosporium has a good effect on flocculating coal slurry.The optimum combination of the experimental is the P.chrysosporium,which is cultured in 2 days,mixed with 2 mL coagulant and 2 mL broth.The flocculant is a broken liquid with pH value of 6.The hightest flocculation ratio is 93.5%.The result of FTIR shows that the biological extraction of P.chrysosporium contains a lot of acidic polysaccharides that has the effect on flocculation.Microbial flocculant molecules and particles of coal slurry could be flocculated by‘‘absorption bridge’’.

Variation of peroxidase isoenzyme and biofilm of Phanerochaete chrysosporium in continuous membrane bioreactor for Reactive Brilliant Red X3-B treatment

The influence of a Reactive Brilliant Red X-3B （RBR X-3B） dye on the peroxidase isoenzyme ofPhanerochaete chrysosporium was determined, and the biofilm structure in a white rot fungal continuous membrane bioreactor （MBR） was also investigated by scanning electron microscope （SEM）. The variation of peroxidase isoenzyme and the decolorization rate in the continuous MBR were evaluated. The results showed that the 100 mg/L RBR X-3B could stimulate the production of the peroxidase isoenzyme in the shaking-flask culture. In addition, two new peroxidase isoenzyme bands with relative mobility （Rf） value of 0.27 and 0.28 appeared, but the activity was lower than the blank control of 11 d. In the continuous MBR, the system worked stably during the first 60 d, the main peroxidase isoenzyme bands existed and three new bands with Rf value of 0.10, 0.27, and 0.28 appeared. Meanwhile, the biofilm grew well and the average decolorization rate could reach 90.6%. But the bands of peroxidase isoenzyme decreased rapidly at day 65, only two bands with Rf value 0.24 and 0.26 existed, and the decolorization rate decreased to 78.3%. Therefore, 5 bottles of P. chrysosporium mycelial pellet were added into the MBR, and then the activity of the peroxidase isoenzyme and the decolorization rate had a slight recovery. Finally, the decolorization rate finally decreased to 75.2%. These results contribute to a comprehensive understanding of the variation of peroxidase isoenzyme and biofilm in continuous MBR by white rot fungi.

Construction of hybrid cell with Phanerochaete chrysosporium to degrade terephthalic acid wastewater——(I) phenotype evidence

The fungi Phanerochaete chrysosporium (PC) and Saccharomyces cerevisiae Y99 and the native bacterium YZ1 were the three parental strains for construction of hybrid cells through protoplast fusion to degrade terephthalic acid (TPA) wastewater. The results showed that the native bacterium YZ1 protoplasm could integrate with that of PC to form the hybrid cell Fhh and the fungus Y99 protoplasm also could integrate with that of Fhh to form the hybrid cell Fhhh. The protoplasts of YZ1 and Y99 could change the morphology of PC spore and mycelium for two times. The hybrid cell Fhhh got the best growth and degradation abilities in the wastewater. It suggested that the hybrid strains obtained from the inter\|kingdom protoplast fusion of the three parental strains could create potential for the purification of TPA wastewater.

Biosorption of lead by Phanerochaete chrysosporium in the form of pellets

The growth of Phanerochaete chrysosporium (ATCC 24725) in pellets was influenced by culture time, medium pH, C/N, surfactant concentration, spore number in inoculum, and shaking rate. The removal of Pb 2+ from aqueous solution by this kind of mycelial pellets was studied. The results indicated that many factors affected biosorption. These factors included pH, Pb 2+ concentration, co ion, adsorption time, and chemical pretreatments of biomass. Under optimum biosorption conditions(pH 4 5, 27℃, 16h), the highest lead uptake of 108 mg/g, was observed with mycelial pellets of 1 5-1 7 mm in diameter which were treated with 0 1 mol/L NaOH solution before adsorption. Pretreatment of biomass with NaOH further increased its biosorption capacity.

Biodegradation of pyrene by Phanerochaete chrysosporium and enzyme activities in soils:Effect of SOM,sterilization and aging

The impacts of soil organic matter （SOM）, aging and sterilization on the production of lignin peroxidase （LIP） and manganese peroxidase （MnP） by Phanerochaete chrysosporium during the biodegradation of pyrene in soils were investigated. The biodegradation of pyrene by P. chrysosporium decreased with increasing SOM content, whereas the maximum activities of LiP and MnP increased, which indicates that SOM outweighed pyrene in controlling enzyme production. Sterilization enhanced the degradation of pyrene due to the elimination of competition from indigenous microbes, whereas aging led to a reduction in the degradation of pyrene primarily through changes in its sorbed forms. Both sterilization and aging could reduce SOM content and alter its structure, which also influenced the bioavailability of pyrene and the enzyme activity. The sterilization and aging processes caused changes in the degradation of pyrene, and the enzyme activities were greater in soils with high SOM contents. MnP was related to the degradation of pyrene to a greater extent, whereas LiP was more related to the decomposition of SOM.

Enhancing Hydrocarbon-Rich Bio-Oil Production via Catalytic Pyrolysis Fortified with Microorganism Pretreatment

A new method of pretreatment of corn straw with Phanerochaete chrysosporium combined with pyrolysis was proposed to improve the quality of bio-oil.The characterization results demonstrated that microbial pretreatment was an effective method to decrease the lignin,which can achieve a maximum removal rate of 44.19%.Due to the destruction of biomass structure,the content of alkali metal and alkaline earth metal is reduced.Meanwhile,the depolymerized biomass structure created better pyrolysis conditions to promote the pyrolysis efficiency,increase the average decomposition rate of pyrolysis and reduce the residue.In fast pyrolysis,because of the enrichment of cellulose and the removal of lignin,the contents of acids,linear carbonyls,furans,and sugars increased while the contents of phenols decreased.As for the catalytic pyrolysis,due to the hydrocarbon pool reaction and shape selection deoxidation of ZSM-5 catalyst,the total hydrocarbon and aromatics contents can significantly increase up to 34.37%and 30.59%,respectively,with 3 weeks of pretreatment.And the the low molecular content of bio-oil increased after pretreatment,which can significantly benefit the entry of primary pyrolysis steam into the catalyst pores to improve the catalytic efficiency and hydrocarbon contents.This method provides a new treatment idea for high-quality utilization of biomass.

Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

Fluorescence spectroscopy characteristics of humic acid by inoculating white-rot fungus during different phases of agricultural waste composting

The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic acid (HA) was studied. The results show that the emission spectra have a sharp peak at 400 nm and a broad shoulder with the maximum centered at 460 nm. The excitation spectra have two peaks and exhibit red shift (shift to longer wavelengths) at 470 nm. The synchronous scan spectra present a number of peaks and shoulders, and the peaks at shorter wavelengths disappear gradually and form a shoulder. At the final stage of composting, the fluorescence spectra have similar shapes, but the fluorescence intensities decrease. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase. Compared with the fluorescence spectroscopy characteristics of HA from soil, the structure of HA from compost is simpler and the activity is higher.

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.

Noncovalent immobilization of manganese peroxidases from P.chrysosporium on carbon nanotubes

Manganese peroxidases(MnP)from Phanerochaete chrysosporium were adsorbed onto multi-walled carbon nanotubes(MWNT).Four different loadings of MnP on MWNTs were investigated,and the maximum enzyme loading of 47.5µg/mg of MWNTs was obtained in 12 h.The adsorbed MnP showed a catalytic activity of up to 0.1 U/mg of the weight of the system of MnP/MWNTs,with 23%of its original activity retained.The AFM image of the adsorbed enzymes indicated that a layer of MnP covered the surface of the MWNTs and retained its original three-dimensional shape.Amino-based nonspecific interactions may play the dominant role in the adsorption of MnP on MWNTs.

Enhancement of Essential Oil Yield from Melaleuca Leucadendra L.Leaves by Lignocellulose Degradation Pre-Treatment Using Filamentous Fungi

The essential oil from Melaleuca leucadendra L.leaves has been widely used as a perfume and traditional remedy,cosmetics and pharmaceutical products ingredient since many years ago.The common technology to recover the oil is hydro-distillation and steam-distillation.However,all oil can not be fully extracted from the leaves by this method due to the recalcitrant structure of leaves that hindrance the access of the solvent.Adding a submerged fermentation as a pretreatment step prior to the extraction process helped to loosen the lignocellulose structure and enhance oil release in the extraction process.In this study,the raw materials were collected from the natural forest in Buru Island,Maluku,Indonesia.The biological agents applied in these processes were Phanerochaete chrysosporium ITBCC136 and Trichoderma viride ITBCC143.The oil extraction process was conducted by method of steam-distillation,the oil was analysed using gas chromatography-mass spectroscopy(GC-MS),and the lignocellulose content in the biomass was measured by the fractionation method.The treatment using T.viride provided the highest increase in yield percentage up to 3.47%as compared with control of 1.45%,with the lowest percentages of the remained cellulose,while the fermentation with the presence of P.chrysosporium did not affect the oil yield even the lignin content was decrease as much as 21%.The percentages of 1,8-cineole in the oil were almost unchanged,which was about 20%of the oil.