Irpex lacteus Dotaz Zobrazit nápovědu
The ligninolytic fungus Irpex lacteus was shown as an efficient degrader of oligocyclic aromatic hydrocarbons (PAHs; 'polycyclic aromatic hydrocarbons') possessing 3-6 aromatic rings in complex liquid media. The strain produced mainly Mn-dependent peroxidase in media without pollutants. Activity of ligninolytic enzymes was higher in a N-limited medium. However, after contamination with PAHs (especially pyrene) the values increased and significant activity of Mn-independent peroxidase appeared in the complex medium. Other factors (such as the increase in nitrogen concentration or the presence of solvent(s) for dissolution of PAHs) had no effect. Cytochrome P-450 was detected in the microsomal fraction of biomass grown in the complex medium. The rate of PAH degradation was also affected by the presence of various combinations of PAHs. However, independently of the enzyme activities, anthracene was shown to have a positive influence on degradation of pyrene and fluoranthene.
White-rot fungi that are efficient lignin degraders responsible for its turnover in nature have appeared twice in the center of biotechnological research - first, when the lignin degradation process started being systematically investigated and major enzyme activities and mechanisms involved were described, and second, when the huge remediation potential of these organisms was established. Originally, Phanerochaete chrysosporium became a model organism, characterized by a secondary metabolism regulatory pattern triggered by nutrient (mostly nitrogen) limitation. Last decade brought evidence of more varied regulatory patterns in white-rot fungi when ligninolytic enzymes were also abundantly synthesized under conditions of nitrogen sufficiency. Gradually, research was focused on other species, among them Irpex lacteus showing a remarkable pollutant toxicity resistance and biodegradation efficiency. Systematic research has built up knowledge of biochemistry and biotechnological applicability of this fungus, stressing the need to critically summarize and estimate these scattered data. The review attempts to evaluate the information on I. lacteus focusing on various enzyme activities and bioremediation of organopollutants in water and soil environments, with the aim of mediating this knowledge to a broader microbiological audience.
- MeSH
- Basidiomycota enzymologie genetika metabolismus MeSH
- biodegradace MeSH
- biotechnologie MeSH
- financování organizované MeSH
- fungální proteiny genetika metabolismus MeSH
- látky znečišťující životní prostředí metabolismus MeSH
- lignin metabolismus MeSH
- regulace genové exprese u hub MeSH
- Publikační typ
- přehledy MeSH
The white rot fungus Irpex lacteus is able to decolorize such synthetic dyes as Reactive Orange 16 and Remazol Brilliant Blue R. Here, we demonstrate that this type of dye decolorization is mainly related to a laccase-like enzyme activity associated with fungal mycelium. In its bound form, the enzyme detected showed a pH optimum of 3.0 for the oxidation of ABTS, DMP and guaiacol, and a pH of 7.0 for syringaldazine. The highest enzymatic activity was obtained with ABTS as substrate. Enzyme activity was fully inhibited with 50mM NaN(3). Depending on the chemical structure of dyes, redox mediators had a positive effect on the dye decolorization by fungal mycelium. Enzyme isolated from fungal mycelium was able to decolorize synthetic dyes in vitro.
- MeSH
- anthrachinony metabolismus MeSH
- azosloučeniny metabolismus MeSH
- barvicí látky metabolismus MeSH
- Basidiomycota enzymologie účinky léků MeSH
- financování organizované MeSH
- inhibitory enzymů farmakologie MeSH
- koncentrace vodíkových iontů účinky léků MeSH
- kultivační média MeSH
- lakasa antagonisté a inhibitory izolace a purifikace metabolismus MeSH
- mycelium enzymologie účinky léků MeSH
- oxidace-redukce účinky léků MeSH
- substrátová specifita účinky léků MeSH
- teplota MeSH
Cordycepin is an essential nucleoside antibiotic with a broad spectrum of physiological functions, which is currently produced by the fermentation of Cordyceps militaris. Even though numerous efforts were made to enhance cordycepin production, the cordycepin yield is still limited. High-cordycepin-yielding strains are still a prerequisite for industrial cordycepin production in large amounts. Screening high-cordycepin-yielding strains from other sources may break new grounds for cordycepin. In this study, Cordyceps hawkesii Gray, with high homology to C. militaris, was selected as the source to screen the cordycepin manufacturing endophytic fungi. Four isolates capable of cordycepin production were successfully obtained among all isolated endophytic fungi. One of the four with better cordycepin yield was identified as Irpex lacteus CHG05, which belongs to the Phlebia species. The response surface methodology was applied to optimize the culture conditions for cordycepin fermentation. 162.05 mg/L of cordycepin with a 53.1% improvement was achieved compared to the original conditions. This study indicates that the endophytic fungi from C. hawkesii Gray could produce cordycepin and served as the first report for cordycepin by the white-rot fungus of I. lacteus. Even though the yield is low compared to C. militaris, this strain provided another choice for enhanced cordycepin in the future.
- MeSH
- Cordyceps * MeSH
- deoxyadenosiny MeSH
- Publikační typ
- časopisecké články MeSH
White rot fungi (WRF) are applicable to biodegradation of recalcitrant pollutants. However, excessive biomass growth typical for WRF cultivation can hinder their large scale applications. Therefore, immobilization of Irpex lacteus to liquid-core alginate beads restricting excessive mycelium growth and simultaneously keeping high degradation rate of pollutants was tested. Effective diffusivities of dyes to the beads varied from (2.98 ± 0.69) × 10(-10) to (10.27 ± 2.60) × 10(-10) m(2)/s. Remazol Brilliant Blue R (RBBR), Reactive Orange 16 (RO16), and Naphthol Blue Black (NBB) were used as model dyes. The immobilized fungus decolorized model dyes when applied both in microwell plates and in fluidized bed reactors. Using the microwell plates, the apparent reaction rate constants ranged from (2.06 ± 0.11) × 10(-2) to (11.06 ± 0.27) × 10(-2) 1/h, depending on the dye used and its initial concentration. High initial concentrations negatively affected the dye decolorization rate. No fungal growth outside the beads was observed in fluidized bed reactors and thus no operational problems linked to an excessive biomass growth occurred. When RBBR was decolorized in subsequent batches in the fluidized bed reactor, the apparent reaction rate constant increased from (11.63 ± 0.35) × 10(-2) to (29.26 ± 7.19) × 10(-2) 1/h.
- MeSH
- algináty chemie MeSH
- barvicí látky metabolismus MeSH
- biodegradace MeSH
- chemické látky znečišťující vodu metabolismus MeSH
- imobilizované buňky chemie metabolismus MeSH
- kyselina glukuronová chemie MeSH
- kyseliny hexuronové chemie MeSH
- mycelium chemie růst a vývoj metabolismus MeSH
- Polyporales chemie růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Use of fungal organisms in rotating biological contactors (RBC) for bioremediation of liquid industrial wastes has so far been limited in spite of their significant biodegradation potential. The purpose was to investigate the power of RBC using Irpex lacteus for decolorization and detoxification of industrial dyes and dyeing textile liquors. Recalcitrant dye Methylene Blue (150 mg L(-1)) was decolorized within 70 days, its mutagenicity removed, and the biological toxicity decreased more than 10-fold. I. lacteus biofilm in the RBC completely decolorized within 26 and 47 days dyeing liquors containing disperse or reactive dyes adjusted to pH4.5 and 5-fold diluted with the growth medium, respectively. Their respective biological toxicity values were reduced 10- to 10(4)-fold in dependence of the test used. A battery of toxicity tests comprising Vibrio fisheri, Lemna minor and Sinapis alba was efficient to monitor the toxicity of textile dyes and wastewaters. Strong decolorization and detoxification power of RBC using I. lacteus biofilms was demonstrated.
- MeSH
- Aliivibrio fischeri účinky léků MeSH
- Araceae účinky léků MeSH
- barva MeSH
- barvicí látky metabolismus MeSH
- biodegradace MeSH
- bioreaktory MeSH
- chemické látky znečišťující vodu metabolismus MeSH
- Magnoliopsida účinky léků MeSH
- methylenová modř metabolismus MeSH
- odpad tekutý - odstraňování přístrojové vybavení metody MeSH
- odpadní voda * toxicita MeSH
- Polyporales metabolismus MeSH
- testy toxicity MeSH
- textilní průmysl MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
he white-rot fungus Irpex lacteus has been reported to be an efficient degrader of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and pentachlorophenol. The fungus produces ligninolytic enzymes laccase, lignin peroxidase and manganese peroxidase (MnP), the latter being the major one produced. MnP was purified using anion exchange and size exclusion chromatography. SDS-PAGE showed the purified MnP to be a monomeric protein of 37 kDa (37.5 kDa using MALDI-TOF) with an isoelectric point at 3.55. The pH optimum was relatively broad, from 4.0 to 7.0 with a peak at pH 5.5. Kinetic constants K(m) were 8 microM for H(2)O(2) and 12 or 31 microM for Mn(2+) depending on the substrate. The enzyme did not perform oxidation in the absence of H(2)O(2) or Mn(2+). MnP was active at 5-70 degrees C with an optimum between 50-60 degrees C. At temperatures above 65 degrees C the enzyme rapidly lost activity. Degradation of four representatives of PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) was tested and the enzyme showed the ability to degrade them in vitro. Major degradation products of anthracene were identified. The results confirm the role of MnP in PAH degradation by I. lacteus, including cleavage of the aromatic ring.
- MeSH
- Basidiomycota enzymologie MeSH
- biodegradace MeSH
- chromatografie iontoměničová MeSH
- financování organizované MeSH
- látky znečišťující životní prostředí metabolismus MeSH
- pentachlorfenol metabolismus MeSH
- peroxidasy izolace a purifikace metabolismus MeSH
- polychlorované bifenyly metabolismus MeSH
- polycyklické aromatické uhlovodíky metabolismus MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
The aim of this study was to determine the efficacy of selected basidiomycetes in the removing of polycyclic aromatic hydrocarbons (PAH) from the creosote-contaminated soil. Fungi Pleurotus ostreatus and Irpex lacteus were supplemented with creosote-contaminated (50-200 mg kg(-1) PAH) soil originating from a wood-preserving plant and incubated at 15 °C for 120 d. Either fungus degraded PAH with 4-6 aromatic rings more efficiently than the microbial community present initially in the soil. PAH removal was higher in P. ostreatus treatments (55-67%) than in I. lacteus treatments (27-36%) in general. P. ostreatus (respectively, I. lacteus) removed 86-96% (47-59%) of 2-rings PAH, 63-72% (33-45%) of 3-rings PAH, 32-49% (9-14%) of 4-rings PAH and 31-38% (11-13%) of 5-6-rings PAH. MIS (Microbial Identification System) Sherlock analysis of the bacterial community determined the presence of dominant Gram-negative bacteria (G-) Pseudomonas in the inoculated soil before the application of fungi. Complex soil microbial community was characterized by phospholipid fatty acids analysis followed by GC-MS/MS. Either fungus induced the decrease of bacterial biomass (G- bacteria in particular), but the soil microbial community was influenced by P. ostreatus in a different way than by I. lacteus. The bacterial community was stressed more by the presence of I. lacteus than P. ostreatus (as proved by the ratio of the fungal/bacterial markers and by the ratio of trans/cis mono-unsaturated fatty acids). Moreover, P. ostreatus stimulated the growth of Gram-positive bacteria (G+), especially actinobacteria and these results indicate the potential of the positive synergistic interaction of this fungus and actinobacteria in creosote biodegradation.
- MeSH
- Bacteria metabolismus MeSH
- biodegradace MeSH
- biomasa MeSH
- kreosot analýza metabolismus MeSH
- látky znečišťující půdu analýza metabolismus MeSH
- mikrobiální společenstva MeSH
- Pleurotus metabolismus MeSH
- polycyklické aromatické uhlovodíky analýza metabolismus MeSH
- Polyporales metabolismus MeSH
- půdní mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
