Hebeloma mesophaeum is an ectomycorrhizal fungus frequently associated with metal disturbed environments. In this work, we examined Ag, Cd, and Zn tolerance of H. mesophaeum isolates from heavy metal-polluted (isolate Prib) and clean (isolate Rez) sites. Both mycelia showed essentially the same level of Ag and Zn tolerance, but Prib was more Cd tolerant. In short-term exposures, Prib accumulated slightly less Cd than Rez. Size exclusion chromatography of cell-free extracts and fluorescence microscopy of hyphae with a Cd-specific fluorescent tracer revealed that substantial proportion of Cd was contained in the vacuoles in both isolates. Considering that the proportion of Cd associated with fractions attributable to Cd complexes with cytosolic, metallothionein (MT) peptides was higher in Prib, we examined the copy number and basal levels of HmMTs genes in Rez and Prib. While no difference between the isolates was observed in the gene copy numbers and basal levels of HmMT1 transcripts, the basal transcription of HmMT3 was 3-fold higher in Prib. These observations suggest that MTs provide in Prib better protection against Cd. Furthermore, the higher Cd tolerance in Prib can be to some extent also supported by the efflux or reduced uptake of Cd in the hyphae.
- MeSH
- antifungální látky metabolismus MeSH
- exprese genu * MeSH
- Hebeloma účinky léků izolace a purifikace MeSH
- kadmium toxicita MeSH
- látky znečišťující životní prostředí metabolismus MeSH
- metalothionein biosyntéza genetika MeSH
- mikrobiologie životního prostředí MeSH
- mycelium účinky léků MeSH
- stříbro metabolismus MeSH
- těžké kovy metabolismus MeSH
- tolerance léku * MeSH
- zinek metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Three different transformation strategies were tested and compared in an attempt to facilitate and improve the genetic transformation of Acremonium chrysogenum, the exclusive producer of the pharmaceutically relevant β-lactam antibiotic cephalosporin C. We investigated the use of high-voltage electric pulse to transform germinated conidia and young mycelium and compared these procedures with traditional PEG-mediated protoplast transformation, using phleomycin resistance as selection marker in all cases. The effect of the field strength and capacitance on transformation frequency and cell viability was evaluated. The electroporation of germinated conidia and young mycelium was found to be appropriate for transforming A. chrysogenum with higher transformation efficiencies than those obtained with the conventional protoplast-based transformation procedures. The developed electroporation strategy is fast, simple to perform, and highly reproducible and avoids the use of chemicals toxic to cells. Electroporation of young mycelium represents an alternative method for transformation of fungal strains with reduced or no sporulation, as often occurs in laboratory-developed strains in the search for high-yielding mutants for industrial bioprocesses.
- MeSH
- Acremonium účinky léků genetika metabolismus MeSH
- bakteriální léková rezistence MeSH
- cefalosporiny biosyntéza MeSH
- elektroporace metody MeSH
- fleomyciny farmakologie MeSH
- mikrobiální viabilita MeSH
- mycelium účinky léků genetika metabolismus MeSH
- protoplasty fyziologie MeSH
- spory hub účinky léků genetika metabolismus MeSH
- transformace genetická * MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Aspergillus oryzae G15 was cultured on Czapek yeast extract agar medium containing different concentrations of copper and lead to investigate the mechanisms sustaining metal tolerance. The effects of heavy metals on biomass, metal accumulation, metallothionein (MT), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were evaluated. Cu and Pb treatment remarkably delayed sclerotial maturation and inhibited mycelial growth, indicating the toxic effects of the metals. Cu decreased sclerotial biomass, whereas Pb led to an increase in sclerotial biomass. G15 bioadsorbed most Cu and Pb ions on the cell surface, revealing the involvement of the extracellular mechanism. Cu treatment significantly elevated MT level in mycelia, and Pb treatment at concentrations of 50-100 mg/L also caused an increase in MT content in mycelia. Both metals significantly increased MDA level in sclerotia. The variations in MT and MDA levels revealed the appearance of heavy metal-induced oxidative stress. The activities of SOD, CAT, and POD varied with heavy metal concentrations, which demonstrated that tolerance of G15 to Cu and Pb was associated with an efficient antioxidant defense system. In sum, the santioxidative detoxification system allowed the strain to survive in high concentrations of Cu and Pb. G15 depended mostly on sclerotial differentiation to defend against Pb stress.
- MeSH
- Aspergillus oryzae účinky léků genetika růst a vývoj metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- katalasa genetika metabolismus MeSH
- malondialdehyd metabolismus MeSH
- měď farmakologie MeSH
- mycelium účinky léků genetika růst a vývoj metabolismus MeSH
- olovo farmakologie MeSH
- oxidační stres účinky léků MeSH
- superoxiddismutasa genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Activity of some enzymes of a Pb-adapted strain of Rhizopus arrhizus augmented significantly during bioaccumulation of Pb from a chemically defined medium. The mycelium of a Pb-adapted strain exposed to 1 microg/mL Pb in a defined medium for 10 d at 28 +/- 2 degrees C exhibited, relative to a wild-type strain, increased activities of antioxidant enzymes, i.e. SOD, CAT and GPX and of enzymes like AP and PPO involved in defense against pathogens. Another response is a significant increase in the cellular thiol content after 4 d. The responses to Pb exposure thus include an increase in the antioxidant and anti-pathogen defense, and an increased metal-chelating ability.
- MeSH
- antifungální látky metabolismus MeSH
- enzymy metabolismus MeSH
- fungální léková rezistence MeSH
- fungální proteiny metabolismus MeSH
- kultivační média chemie MeSH
- mycelium enzymologie metabolismus účinky léků MeSH
- olovo metabolismus MeSH
- Rhizopus enzymologie metabolismus účinky léků MeSH
- sulfhydrylové sloučeniny metabolismus 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
Significant effects of humic acid-like material (HALM) extracted from sewage sludge on dry matter production of cultures of ectomycorrhizal basidiomycetes were found in vitro. Mycelial growth of the majority of isolates tended to increase in the presence of the HALM and this effect was significant for 6 isolates. Strongest stimulation was observed in the case of Amanita muscaria, Leccinum aurantiacum and Lactarius deterrimus. The results suggest that the HALM can be used as an additive to media for cultivation of ectomycorrhizal basidiomycetes.
- MeSH
- Amanita růst a vývoj účinky léků MeSH
- financování organizované využití MeSH
- houby růst a vývoj účinky léků MeSH
- huminové látky parazitologie MeSH
- interpretace statistických dat MeSH
- kokultivační techniky metody statistika a číselné údaje využití MeSH
- mycelium růst a vývoj účinky léků MeSH
- mykorhiza růst a vývoj účinky léků MeSH
- MeSH
- aminy farmakokinetika metabolismus MeSH
- antioxidancia farmakokinetika metabolismus MeSH
- Aspergillus niger metabolismus patogenita účinky léků MeSH
- mitochondrie patologie účinky léků ultrastruktura MeSH
- mycelium metabolismus účinky léků ultrastruktura MeSH
- oxidační stres genetika MeSH
- Publikační typ
- srovnávací studie MeSH
