Pentachlorophenol and spent engine oil degradation by Mucor ramosissimus

Pentachlorophenol (PCP) has been widely used for many years and belongs to the most toxic pollutants. Spent engine oils enter environment every day in many ways. Both of them cause great environmental concern. In the present work we focused on identifying metabolites of PCP biodegradation formed in the cultures of Mucor ramosissimus IM 6203 and optimizing medium composition to enhance PCP removal in the presence of engine oil acting as a carbon source. Pentachlorophenol (PCP) to tetrachlorohydroquinone (TCHQ) transformation was the most interesting transformation conducted by the tested strain. TCHQ was further transformed to 2,3,5,6-TCP and 2,3,4,6- TCP. Strain IM 6203 is also capable of PCP transformation to corresponding anisoles – pentachloromethoxybenzene (PCMB) and pentachloroethoxybenzene (PCEB). Characterization of enzymatic background involved in PCP to TCHQ transformation showed that TCHQ formation is catalyzed by inductive and cytochrome P-450 dependent enzymatic system. Experiments conducted on mineral medium allowed defining the optimal quantitative and qualitative medium make-up for PCP to TCHQ transformation. Biodegradation of PCP on the optimized synthetic medium X was more efficient than on rich Sabouraud medium. The tested strain is capable of growing in the presence of spent engine oil therefore we checked the ability of PCP transformation on optimized synthetic medium containing oil as a carbon source. The obtained results showed that PCP removal and TCHQ formation occurred were found to be the most efficient on the oil containing medium (OX medium). PCP removal and TCHQ formation after 240 h of culturing reached 1.19 mg/l and 0.89 mg/l, respectively. Additionally, 55.5% of oil introduced to the medium was removed during 10 days of the experiment. PCP biodegradation mechanisms used by Mucor species have not been sufficiently explained. The presented results point to the tested strain as an interesting model for the research on fungal PCP biodegradation in the areas highly contaminated with engine oil and for its future application in PCP and oils removal

Mikrobiologiczny rozkład pentachlorofenolu

Pentachlorophenol (PCP) is a toxic xenobiotic of great environmental concern. It has been widely used for many years as a bactericide, fungicide, defoliant, herbicide and wood preservative. In this article, PCP properties, microbial biodegradation and other approaches of this xenobiotic elimination from contaminated areas are reviewed.Pracê finansowano w ramach badań własnych Uniwersytetu Łódzkiego nr 505/387, 505/488 i 505/705 oraz z grantu międzynarodowego otrzymanego przez KMPiB U£ z Unii Europejskiej, DG XII, INCO-COPERNICUS (Contract No. 15-CT 98-0114). Rafał Szewczyk, Jerzy Długoński 132 P

Alachlor oxidation by the filamentous fungus Paecilomyces marquandii

Alachlor, a popular chloroacetanilide herbicide, can be a potential health risk factor. Soil microorganisms are primarily responsible for conversion and migration of alachlor in natural environment, but knowledge concerning alachlor biodegradation is not complete. Therefore, we studied the ability of Paecilomyces marquandii, soil fungus tolerant to heavy metals, to eliminate alachlor and proposed a new pathway of its transformation. After 7 days of incubation only 3.3% of alachlor was detected from an initial concentration 50 mg L-1 and 20.1% from a concentration 100 mg L-1. The qualitative IDA LC-MS analysis showed the presence of ten metabolites. All of them were dechlorinated mainly through oxidation, but also reductive dechlorination was observed. The main route of alachlor conversion progressed via N-acetyl oxidation resulting in the formation of mono-, di- and trihydroxylated byproducts. N-acetyl oxidation as a dominant route of alachlor metabolism by fungi has not been described so far. The toxicity of alachlor tested with Artemia franciscana did not increase after treatment with P. marquandii cultures. Paecilomyces marquandii strain seems to be an interesting model for the research on alachlor conversion by soil microscopic fungi, due to its dechlorination and hydroxylation ability as well as high tolerance to heavy metals.Grant of the National Centre for Science in Cracow, Poland, No UMO-2011/01/B/NZ9/0289

Intracellular proteome expression during 4-n-nonylphenol biodegradation by the filamentous fungus Metarhizium robertsii

4-n-nonylphenol (4-n-NP) is an endocrine disrupting compound (EDC); pollutants that cause serious disturbances in the environment. This study shows the degradation pathway and initial proteome analysis in cultures of a fungus that actively degrades 4-n-NP, Metarhizium robertsii. The research revealed the presence of 14 4-n-NP metabolites formed as a result of the oxidation of the alkyl chain and benzene ring, which leads to the complete decomposition of the compound. Based on the trend and quantitative analysis of the formation of 4-n-NP derivatives, the best conditions for proteome analysis were established. The data collected allowed the formulation of an explanation of the microorganism's strategy towards the removal of 4-n-NP. The main groups of proteins engaged in the removal of the xenobiotic are: oxidation-reduction systems related to nitroreductase-like proteins, ROS defense systems (peroxiredoxin and superoxide dismutase), the TCA cycle and energy-related systems. Principal components analysis was applied to unidentified proteins, resulting in the formulation of three subgroups and initial classification of these proteins

Use of Styrene as Sole Carbon Source by the Fungus Exophiala oligosperma: Optimization and Modeling of Biodegradation, Pathway Elucidation, and Cell Membrane Composition

Biodegradation of styrene by Exophiala sp. was tested at different initial concentrations (19.3–170.6 mg l−1), pH (2.8–8.7), and temperatures (19.8–45.1 °C), for 120 h according to a 23 full-factorial central composite design. The specific growth rate (SGR, per hour) and specific styrene utilization rate (SUR, milligrams of styrene per milligram of biomass per hour) values were used as the response variables for optimization purposes. The interactions between concentration and temperature (P = 0.022), and pH and temperature (P = 0.010) for SGR, and interactions between concentration and temperature (P = 0.012) for SUR were found to be statistically significant. The optimal values for achieving high SGR (0.15 h−1) and SUR (0.3622 mg styrene mg−1 biomass h−1) were calculated from the regression model equation. Those values are C o  = 89.1 mg l−1, pH = 5.4, and T = 31.5 °C for SGR and C o  = 69.2 mg l−1, pH = 5.5, and T = 32.4 °C for SUR. It was also observed that the Exophiala strain degrades styrene via phenylacetic acid, involving initial oxidation of the vinyl side chain. Besides, in the presence of styrene, changes in the fatty acids profile were also observed. It is hypothesized that an increasing amount of linoleic acid (18:2) may be involved in the protection of the fungus against toxic substrate

Utilization of 4-n-nonylphenol by Metarhizium sp. isolates*

Nonylphenol (4-NP) is a xenobiotic classified as an endocrine disrupting compound with an ability to interfere with hormonal systems of numerous organisms including humans. It is widely distributed not only in aquatic but also in terrestrial systems. The aim of this study was to evaluate the ability of cosmopolitan fungus Metarhizium (commonly persistent in soil as a facultative insect pathogen, controlling populations of arthropods in natural environment) to degrade 4-n-nonylphenol. All isolates examined in this work were identified to a species rank based on five, independent genetic markers. Among eight Metarhizium strains; six of them have been identified as M. robertsii, and two others as M. brunneum and M. lepidiotae. All investigated Metarhzium isolates were found to eliminate 4-n-NP with significant efficiency (initial xenobiotic concentration 50 mg L -1 ). The degradation process was very effective and at 24h of incubation 50-90% of 4-n-NP was eliminated by certain strains, while extended incubation resulted in further utilization of this compound. At the end of the experiments 64-99% of 4-n-NP was removed from the culture medium. Additionally, in all tested cultures three major metabolites were detected: 4-hydroxybenzoic acid; 2-(4-hydroxyphenyl)acetic acid and 4-hydroxyphenylpentanoic acid. The obtained results indicate that Metarhizium sp. possesses an ability to degrade NP and can serve as a potential candidate for further biodegradation studies

Di(n-butyl) phthalate has no effect on the rat prepubertal testis despite its estrogenic activity in vitro

The aim of this study was to assess the impact of di(n-butyl) phthalate (DBP) on the rat’s prepubertal testis. Male Wistar rats were given daily subcutaneous injections with DBP (20 or 200 μg) or a vehicle from the 5th to the 15th postnatal day (pd). On the 16th pd, the rats were euthanized, and the testes were dissected, weighed, and paraffin embedded. The blood was collected to determine the serum levels of testosterone (T), estradiol (E) and FSH. The following parameters were assessed in the testis sections: diameter and length of seminiferous tubules (st), numbers of spermatogonia A + intermediate + B (A/In/B), preleptotene spermatocytes (PL), leptotene + zygotene + pachytene spermatocytes (L/Z/PA) and Sertoli cells per testis, percentage of st containing gonocytes or pachytene spermatocytes or lumen. An estrogenicity in vitro test was performed by means of a transgenic yeast strain expressing human estrogen receptor alpha. At both doses, DBP had no influence on testis and seminal vesicle weight, st diameter and length, number of germ and Sertoli cells per testis, percentage of st containing gonocytes or pachytene spermatocytes or lumen. DBP did not change E, T or FSH serum levels. The in vitro yeast screen showed that DBP was a weak estrogenic compound, approximately six to seven orders of magnitude less potent than 17β-estradiol. In conclusion, exposure of a rat to DBP in doses 100 or 1,000-fold higher than a Tolerable Daily Intake for humans had no effect on its testicular development. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 685–689

Mechanism study of alachlor biodegradation by Paecilomycesmarquandii with proteomic and metabolomic methods

Alachlor is an herbicide that is widely used worldwide to protect plant crops against broadleaf weedsand annual grasses. However, due to its endocrine-disrupting activity, its application had been bannedin the European Union. As described in our earlier work, Paecilomyces marquandii is a microscopic funguscapable of alachlor removal by N-acetyl oxidation. Our current work uses proteomics and metabolomicsto gain a better understanding of alachlor biodegradation by the microscopic fungus P. marquandii.The data revealed that the addition of alachlor reduced the culture growth and glucose consump-tion rates. Moreover, the rates of glycolysis and the tricarboxylic acids (TCA) cycle increased duringthe initial stage of growth, and there was a shift toward the formation of supplementary materials(UDP-glucose/galactose) and reactive oxygen species (ROS) scavengers (ascorbate). Proteomic analy-sis revealed that the presence of xenobiotics resulted in a strong upregulation of enzymes related toenergy, sugar metabolism and ROS production. However, the unique overexpression of cyanide hydratasein alachlor-containing cultures may implicate this enzyme as the key protein involved in the alachlorbiodegradation pathway. The characterization of P. marquandii-mediated alachlor removal in terms of cellstructure and function provides a deeper insight into the strategies of microorganisms toward xenobioticbiodegradation.This study was supported by the grant of the National Science Centre, Poland (Project No. UMO-2011/01/B/NZ9/02898)