- Klíčová slova
- Mucidin,
- MeSH
- antibakteriální látky * dějiny MeSH
- antifungální látky dějiny MeSH
- dějiny 20. století MeSH
- objevování léků * dějiny MeSH
- Check Tag
- dějiny 20. století MeSH
- Publikační typ
- biografie MeSH
- historické články MeSH
Polyesteramides based on epsilon-caprolactam and epsilon-caprolactone differing in the content of ester-amide structural units were subjected to biodegradation - composting in a big compost pile under controlled conditions (controlled composting) and in small composters at a steady temperature of 60 degrees C (isothermal composting). Both types of composting resulted in degradation of the polyesteramides depending on copolymer composition, isothermal composting being more robust. The contribution of abiotic hydrolysis to the degradation of polyesteramides was studied at 60 degrees C in buffer solutions with pH 5.4, 7.4 and 8.4. The prevailing effect of abiotic hydrolysis over biological one was shown at 60 degrees C. Ester bonds in polyestramide chains were preferentially cleaved; therefore, the scope of degradation increased with the content of ester units in the copolymer.
- MeSH
- biodegradace MeSH
- financování organizované MeSH
- houby metabolismus MeSH
- hydrolýza MeSH
- kaprolaktam chemická syntéza chemie metabolismus MeSH
- kapronáty chemická syntéza chemie metabolismus MeSH
- laktony chemická syntéza chemie metabolismus MeSH
- polymery chemická syntéza chemie metabolismus MeSH
- půda analýza MeSH
- teplota MeSH
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 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.
Vyd. 1. 263 s., [16] s. obr. příl. : il., tab. ; 24 cm
- Klíčová slova
- jedlé houby,
- MeSH
- fytoterapie MeSH
- zemědělství trendy MeSH
- Publikační typ
- populární práce MeSH
- Konspekt
- Zahrádkářství
- NLK Obory
- zájmy a záliby
Supercritical fluid extraction (SFE) with pure carbon dioxide was used to obtain desorption curves of PAHs from four contaminated industrial soils. Total PAH concentrations ranged from 1495 to 2439 mg/kg. The desorption curves were fitted with a simple two-site model to determine the rapidly released fraction (F) representing bioavailability of PAHs. The Fdata obtained under various SFE pressures were compared with degradation results of a composting method applied on the soils. After composting and consequent long-term maturation, the residual PAH contaminations ranged from 4 to 36% of the original values. A possible explanation of the result variations is the different bioavailability of the pollutants. The best correlations between degradation results and F fraction were obtained applying 50 degrees C and 300 bar. The F values gave very good agreement with degradation efficiencies and the total regression coefficients (r) ranged from 0.81 to 0.99. The degradation results together with bioavailable fractions appeared to be consistentwith organic carbon contents in the soils and with volatile fractions of organics. The results indicate that SFE could be a rapid testto predict bioremediation results of composting of PAH-contaminated soils.
