Chlorhexidine (CHX) and octenidine (OCT), antimicrobial compounds used in oral care products (toothpastes and mouthwashes), were recently revealed to interfere with human sex hormone receptor pathways. Experiments employing model organisms-white-rot fungi Irpex lacteus and Pleurotus ostreatus-were carried out in order to investigate the biodegradability of these endocrine-disrupting compounds and the capability of the fungi and their extracellular enzyme apparatuses to biodegrade CHX and OCT. Up to 70% ± 6% of CHX was eliminated in comparison with a heat-killed control after 21 days of in vivo incubation. An additional in vitro experiment confirmed manganese-dependent peroxidase and laccase are partially responsible for the removal of CHX. Up to 48% ± 7% of OCT was removed in the same in vivo experiment, but the strong sorption of OCT on fungal biomass prevented a clear evaluation of the involvement of the fungi or extracellular enzymes. On the other hand, metabolites indicating the enzymatic transformation of both CHX and OCT were detected and their chemical structures were proposed by means of liquid chromatography-mass spectrometry. Complete biodegradation by the ligninolytic fungi was not achieved for any of the studied analytes, which emphasizes their recalcitrant character with low possibility to be removed from the environment.

• Keywords
• chlorhexidine, dental hygiene, laccase, ligninolytic fungi, manganese-dependent peroxidase, octenidine, personal care products, quaternary ammonium compounds, recalcitrant pollutant,
• MeSH
• Anti-Infective Agents, Local metabolism   MeSH
• Biodegradation, Environmental * MeSH
• Chlorhexidine chemistry   metabolism   MeSH
• Fungi metabolism   MeSH
• Imines MeSH
• Humans MeSH
• Metabolomics methods   MeSH
• Pyridines chemistry   metabolism   MeSH
• Dental Care MeSH
• Transformation, Genetic MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Infective Agents, Local MeSH
• Chlorhexidine MeSH
• Imines MeSH
• octenidine MeSH Browser
• Pyridines MeSH

Secondary plant metabolites (SPMEs) play an important role in plant survival in the environment and serve to establish ecological relationships between plants and other organisms. Communication between plants and microorganisms via SPMEs contained in root exudates or derived from litter decomposition is an example of this phenomenon. In this review, the general aspects of rhizodeposition together with the significance of terpenes and phenolic compounds are discussed in detail. We focus specifically on the effect of SPMEs on microbial community structure and metabolic activity in environments contaminated by polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Furthermore, a section is devoted to a complex effect of plants and/or their metabolites contained in litter on bioremediation of contaminated sites. New insights are introduced from a study evaluating the effects of SPMEs derived during decomposition of grapefruit peel, lemon peel, and pears on bacterial communities and their ability to degrade PCBs in a long-term contaminated soil. The presented review supports the "secondary compound hypothesis" and demonstrates the potential of SPMEs for increasing the effectiveness of bioremediation processes.

• Keywords
• bioremediation, carbon flow, community structure, secondary plant metabolites (SPMEs),
• MeSH
• Bacteria classification   isolation & purification   metabolism   MeSH
• Biodegradation, Environmental * MeSH
• Soil Pollutants chemistry   toxicity   MeSH
• Polychlorinated Biphenyls toxicity   MeSH
• Soil Microbiology * MeSH
• Plants metabolism   microbiology   MeSH
• Secondary Metabolism MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Soil Pollutants MeSH
• Polychlorinated Biphenyls 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 enzymology   genetics   metabolism   MeSH
• Biodegradation, Environmental MeSH
• Biotechnology * MeSH
• Fungal Proteins genetics   metabolism   MeSH
• Environmental Pollutants metabolism   MeSH
• Lignin metabolism   MeSH
• Gene Expression Regulation, Fungal MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Fungal Proteins MeSH
• Environmental Pollutants MeSH
• Lignin 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.

• MeSH
• Basidiomycota enzymology   genetics   metabolism   MeSH
• Biodegradation, Environmental MeSH
• Fungal Proteins genetics   metabolism   MeSH
• Lignin metabolism   MeSH
• Peroxidases genetics   metabolism   MeSH
• Polycyclic Aromatic Hydrocarbons chemistry   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Fungal Proteins MeSH
• Lignin MeSH
• Peroxidases MeSH
• Polycyclic Aromatic Hydrocarbons MeSH

Enzyme activity was determined in cultures of Pleurotus ostreatus and Trametes versicolor with cellulose as a sole C source and high C/N ratio. The fungi were able to grow and produce laccase and Mn-peroxidase (MnP) at 5-35 degrees C, the highest production being recorded at 25-30 degrees C in P. ostreatus and at 35 degrees C in T. versicolor. Production of both enzymes at 10 degrees C accounted only for 4-20% of the maximum value. Temperature optima for enzyme activity were 50 and 55 degrees C for P. ostreatus and T. versicolor laccases, respectively, and 60 degrees C for MnP. Temperatures causing 50% loss of activity after 24 h were 32 and 47 degrees C for laccases and 36 and 30 degrees C for MnP from P. ostreatus and T. versicolor, respectively.

• MeSH
• Fungal Proteins chemistry   metabolism   MeSH
• Laccase chemistry   metabolism   MeSH
• Lignin metabolism   MeSH
• Peroxidases metabolism   MeSH
• Pleurotus enzymology   growth & development   MeSH
• Polyporales enzymology   growth & development   MeSH
• Enzyme Stability MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Fungal Proteins MeSH
• Laccase MeSH
• Lignin MeSH
• manganese peroxidase MeSH Browser
• Peroxidases MeSH

The extracellular enzyme activity and changes in soil bacterial community during the growth of the ligninolytic fungus Pleurotus ostreatus were determined in nonsterile soil with low and high available carbon content. In soil with P. ostreatus, the activity of ligninolytic enzymes laccase and Mn-peroxidase was several orders of magnitude higher than in soil without the fungus. Addition of lignocellulose to soil increased the activity of cellulolytic fungi and the production of Mn-peroxidase by P. ostreatus. The counts of heterotrophic bacteria were more significantly affected by the presence of lignocellulose than by P. ostreatus. The effects of both substrate addition and time (succession) were more significant factors affecting the soil bacterial community than the presence of P. ostreatus. Bacterial community structure was affected by fungal colonization in low carbon soil, where a decrease of diversity and changes in substrate utilization profiles were detected.

• MeSH
• Bacteria growth & development   MeSH
• Cellulose metabolism   MeSH
• Fungal Proteins biosynthesis   MeSH
• Laccase biosynthesis   MeSH
• Lignin metabolism   MeSH
• Peroxidases biosynthesis   MeSH
• Pleurotus enzymology   growth & development   MeSH
• Soil MeSH
• Soil Microbiology * MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cellulose MeSH
• Fungal Proteins MeSH
• Laccase MeSH
• Lignin MeSH
• lignocellulose MeSH Browser
• manganese peroxidase MeSH Browser
• Peroxidases MeSH
• Soil MeSH
• Carbon MeSH