TY - JOUR AB - Expanding industrialization and the associated usage and production of mineral oil products has caused a worldwide spread of polycyclic aromatic hydrocarbons. These pollutants accumulate and persist under anoxic conditions but little is known about the biochemical reactions catalyzing their anaerobic degradation. Recently, carboxylation of naphthalene was demonstrated for the sulfate-reducing culture N47. Proteogenomic studies on N47 allowed the identification of a gene cluster with products suggested to be involved in the initial reaction of naphthalene degradation. Here, we performed comparative proteomic studies with N47 proteins extracted from naphthalene versus 2-methylnapththalene-grown cells on blue native PAGE. The analysis led to the identification of subunits of the naphthalene carboxylase of N47. Moreover, we show that the identified subunits are encoded in an operon structure within the previously mentioned naphthalene carboxylase gene cluster. These findings were supported by a pull-down experiment revealing in vitro interaction partners of a heterologously produced GST-tagged naphthalene carboxylase subunit. Based on these lines of evidence, naphthalene carboxylase is proposed to be a complex of about 750kDa. Naphthalene carboxylase can be seen as a prototype of a new enzyme family of UbiD like de-/carboxylases catalyzing the anaerobic activation of non-substituted polycyclic aromatic hydrocarbons. AU - Kölschbach, J.S. AU - Mouttaki, H. AU - Merl-Pham, J. AU - Arnold, M.E.* AU - Meckenstock, R.U.* C1 - 55694 C2 - 46490 CY - 233 Spring St, New York, Ny 10013 Usa SP - 241-250 TI - Identification of naphthalene carboxylase subunits of the sulfate-reducing culture N47. JO - Biodegradation VL - 193 IS - 4 PB - Springer PY - 2019 SN - 0923-9820 ER - TY - JOUR AB - Aromatic hydrocarbons belong to the most abundant contaminants in groundwater systems. They can serve as carbon and energy source for a multitude of indigenous microorganisms. Predictions of contaminant biodegradation and microbial growth in contaminated aquifers are often vague because the parameters of microbial activity in the mathematical models used for predictions are typically derived from batch experiments, which don't represent conditions in the field. In order to improve our understanding of key drivers of natural attenuation and the accuracy of predictive models, we conducted comparative experiments in batch and sediment flow-through systems with varying concentrations of contaminant in the inflow and flow velocities applying the aerobic Pseudomonas putida strain F1 and the denitrifying Aromatoleum aromaticum strain EbN1. We followed toluene degradation and bacterial growth by measuring toluene and oxygen concentrations and by direct cell counts. In the sediment columns, the total amount of toluene degraded by P. putida F1 increased with increasing source concentration and flow velocity, while toluene removal efficiency gradually decreased. Results point at mass transfer limitation being an important process controlling toluene biodegradation that cannot be assessed with batch experiments. We also observed a decrease in the maximum specific growth rate with increasing source concentration and flow velocity. At low toluene concentrations, the efficiencies in carbon assimilation within the flow-through systems exceeded those in the batch systems. In all column experiments the number of attached cells plateaued after an initial growth phase indicating a specific "carrying capacity" depending on contaminant concentration and flow velocity. Moreover, in all cases, cells attached to the sediment dominated over those in suspension, and toluene degradation was performed practically by attached cells only. The observed effects of varying contaminant inflow concentration and flow velocity on biodegradation could be captured by a reactive-transport model. By monitoring both attached and suspended cells we could quantify the release of new-grown cells from the sediments to the mobile aqueous phase. Studying flow velocity and contaminant concentrations as key drivers of contaminant transformation in sediment flow-through microcosms improves our system understanding and eventually the prediction of microbial biodegradation at contaminated sites. AU - Garzorz-Stark, N.* AU - Speth, P.* AU - Jargosch, M.* AU - Biedermann, T.* AU - Eyerich, K.* AU - Eyerich, S. C1 - 53808 C2 - 45030 CY - 233 Spring St, New York, Ny 10013 Usa SP - S170-S170 TI - The relevance of CMV reactivation in immunocompromised patients suffering from chronic inflammatory skin diseases. JO - Biodegradation VL - 138 IS - 5 PB - Springer PY - 2018 SN - 0923-9820 ER - TY - JOUR AB - Aromatic hydrocarbons belong to the most abundant contaminants in groundwater systems. They can serve as carbon and energy source for a multitude of indigenous microorganisms. Predictions of contaminant biodegradation and microbial growth in contaminated aquifers are often vague because the parameters of microbial activity in the mathematical models used for predictions are typically derived from batch experiments, which don't represent conditions in the field. In order to improve our understanding of key drivers of natural attenuation and the accuracy of predictive models, we conducted comparative experiments in batch and sediment flow-through systems with varying concentrations of contaminant in the inflow and flow velocities applying the aerobic Pseudomonas putida strain F1 and the denitrifying Aromatoleum aromaticum strain EbN1. We followed toluene degradation and bacterial growth by measuring toluene and oxygen concentrations and by direct cell counts. In the sediment columns, the total amount of toluene degraded by P. putida F1 increased with increasing source concentration and flow velocity, while toluene removal efficiency gradually decreased. Results point at mass transfer limitation being an important process controlling toluene biodegradation that cannot be assessed with batch experiments. We also observed a decrease in the maximum specific growth rate with increasing source concentration and flow velocity. At low toluene concentrations, the efficiencies in carbon assimilation within the flow-through systems exceeded those in the batch systems. In all column experiments the number of attached cells plateaued after an initial growth phase indicating a specific "carrying capacity" depending on contaminant concentration and flow velocity. Moreover, in all cases, cells attached to the sediment dominated over those in suspension, and toluene degradation was performed practically by attached cells only. The observed effects of varying contaminant inflow concentration and flow velocity on biodegradation could be captured by a reactive-transport model. By monitoring both attached and suspended cells we could quantify the release of new-grown cells from the sediments to the mobile aqueous phase. Studying flow velocity and contaminant concentrations as key drivers of contaminant transformation in sediment flow-through microcosms improves our system understanding and eventually the prediction of microbial biodegradation at contaminated sites. AU - Grösbacher, M. AU - Eckert, D.* AU - Cirpka, O.A.* AU - Griebler, C. C1 - 53079 C2 - 44779 CY - 233 Spring St, New York, Ny 10013 Usa SP - 211-232 TI - Contaminant concentration versus flow velocity: Drivers of biodegradation and microbial growth in groundwater model systems. JO - Biodegradation VL - 29 IS - 3 PB - Springer PY - 2018 SN - 0923-9820 ER - TY - JOUR AB - Aromatic hydrocarbons belong to the most abundant contaminants in groundwater systems. They can serve as carbon and energy source for a multitude of indigenous microorganisms. Predictions of contaminant biodegradation and microbial growth in contaminated aquifers are often vague because the parameters of microbial activity in the mathematical models used for predictions are typically derived from batch experiments, which don't represent conditions in the field. In order to improve our understanding of key drivers of natural attenuation and the accuracy of predictive models, we conducted comparative experiments in batch and sediment flow-through systems with varying concentrations of contaminant in the inflow and flow velocities applying the aerobic Pseudomonas putida strain F1 and the denitrifying Aromatoleum aromaticum strain EbN1. We followed toluene degradation and bacterial growth by measuring toluene and oxygen concentrations and by direct cell counts. In the sediment columns, the total amount of toluene degraded by P. putida F1 increased with increasing source concentration and flow velocity, while toluene removal efficiency gradually decreased. Results point at mass transfer limitation being an important process controlling toluene biodegradation that cannot be assessed with batch experiments. We also observed a decrease in the maximum specific growth rate with increasing source concentration and flow velocity. At low toluene concentrations, the efficiencies in carbon assimilation within the flow-through systems exceeded those in the batch systems. In all column experiments the number of attached cells plateaued after an initial growth phase indicating a specific "carrying capacity" depending on contaminant concentration and flow velocity. Moreover, in all cases, cells attached to the sediment dominated over those in suspension, and toluene degradation was performed practically by attached cells only. The observed effects of varying contaminant inflow concentration and flow velocity on biodegradation could be captured by a reactive-transport model. By monitoring both attached and suspended cells we could quantify the release of new-grown cells from the sediments to the mobile aqueous phase. Studying flow velocity and contaminant concentrations as key drivers of contaminant transformation in sediment flow-through microcosms improves our system understanding and eventually the prediction of microbial biodegradation at contaminated sites. AU - Lovaszi, M.* AU - Gácsi, A.* AU - Csányi, E.* AU - Kovács, D.* AU - Eyerich, K.* AU - Kemeny, L.* AU - Szegedi, A.* AU - Zouboulis, C.C.* AU - Eyerich, S. AU - Torcsik, D.* C1 - 53809 C2 - 45029 CY - 233 Spring St, New York, Ny 10013 Usa SP - S174-S174 TI - Sebum component lipids penetrate through the epidermis and modulate macrophage - P-acnes interaction. JO - Biodegradation VL - 138 IS - 5 PB - Springer PY - 2018 SN - 0923-9820 ER - TY - JOUR AB - An anaerobic culture (1MN) was enriched with 1-methylnaphthalene as sole source of carbon and electrons and Fe(OH)(3) as electron acceptor. 1-Naphthoic acid was produced as a metabolite during growth with 1-methylnaphthalene while 2-naphthoic acid was detected with naphthalene and 2-methylnaphthalene. This indicates that the degradation pathway of 1-methylnaphthalene might differ from naphthalene and 2-methylnaphthalene degradation in sulfate reducers. Terminal restriction fragment length polymorphism and pyrosequencing revealed that the culture is mainly composed of two bacteria related to uncultured Gram-positive Thermoanaerobacteraceae and uncultured gram-negative Desulfobulbaceae. Stable isotope probing showed that a C-13-carbon label from C-13(10)-naphthalene as growth substrate was mostly incorporated by the Thermoanaerobacteraceae. The presence of putative genes involved in naphthalene degradation in the genome of this organism was confirmed via assembly-based metagenomics and supports that it is the naphthalene-degrading bacterium in the culture. Thermoanaerobacteraceae have previously been detected in oil sludge under thermophilic conditions, but have not been shown to degrade hydrocarbons so far. The second member of the community belongs to the Desulfobulbaceae and has high sequence similarity to uncultured bacteria from contaminated sites including recently proposed groundwater cable bacteria. We suggest that the gram-positive Thermoanaerobacteraceae degrade polycyclic aromatic hydrocarbons while the Desulfobacterales are mainly responsible for Fe(III) reduction. AU - Marozava, S. AU - Mouttaki, H. AU - Müller, H.* AU - Laban, N.A.* AU - Probst, A.J.* AU - Meckenstock, R.U.* C1 - 52412 C2 - 43951 CY - New York SP - 23-39 TI - Anaerobic degradation of 1-methylnaphthalene by a member of the Thermoanaerobacteraceae contained in an iron-reducing enrichment culture. JO - Biodegradation VL - 29 IS - 1 PB - Springer PY - 2018 SN - 0923-9820 ER - TY - JOUR AB - Pristine and energy-limited aquifers are considered to have a low resistance and resilience towards organic pollution. An experiment in an indoor aquifer system revealed an unexpected high intrinsic potential for the attenuation of a short-term toluene contamination. A 30 h pulse of 486 mg of toluene, used as a model contaminant, and deuterated water (D2O) through an initially pristine, oxic, and organic carbon poor sandy aquifer revealed an immediate aerobic toluene degradation potential. Based on contaminant and tracer break-through curves, as well as mass balance analyses and reactive transport modelling, a contaminant removal of 40 % over a transport distance of only 4.2 m in less than one week of travel time was obtained. The mean first-order degradation rate constant was λ = 0.178 day-1, corresponding to a half-life time constant T1/2 of 3.87 days. Toluene-specific stable carbon isotope analysis independently proved that the contaminant mass removal can be attributed to microbial biodegradation. Since average doubling times of indigenous bacterial communities were in the range of months to years, the aerobic biodegradation potential observed is assumed to be present and active in the pristine, energy-limited groundwater ecosystems at any time. Follow-up experiments and field studies will help to quantify the immediate natural attenuation potential of aquifers for selected priority contaminants and will try to identify the key-degraders within the autochthonous microbial communities. AU - Herzyk, A. AU - Maloszewski, P. AU - Qiu, S. AU - Elsner, M. AU - Griebler, C. C1 - 27483 C2 - 32692 CY - New York SP - 325-336 TI - Intrinsic potential for immediate biodegradation of toluene in a pristine, energy-limited aquifer. JO - Biodegradation VL - 25 IS - 3 PB - Springer PY - 2014 SN - 0923-9820 ER - TY - JOUR AB - The influence of transverse mixing on competitive aerobic and anaerobic biodegradation of a hydrocarbon plume was investigated using a two-dimensional, bench-scale flow-through laboratory tank experiment. In the first part of the experiment aerobic degradation of increasing toluene concentrations was carried out by the aerobic strain Pseudomonas putida F1. Successively, ethylbenzene (injected as a mixture of unlabeled and fully deuterium-labeled isotopologues) substituted toluene; nitrate was added as additional electron acceptor and the anaerobic denitrifying strain Aromatoleum aromaticum EbN1 was inoculated to study competitive degradation under aerobic / anaerobic conditions. The spatial distribution of anaerobic degradation was resolved by measurements of compound-specific stable isotope fractionation induced by the anaerobic strain as well as compound concentrations. A fully transient numerical reactive transport model was employed and calibrated using measurements of electron donors, acceptors and isotope fractionation. The aerobic phases of the experiment were successfully reproduced using a double Monod kinetic growth model and assuming an initial homogeneous distribution of P. putida F1. Investigation of the competitive degradation phase shows that the observed isotopic pattern cannot be explained by transverse mixing driven biodegradation only, but also depends on the inoculation process of the anaerobic strain. Transient concentrations of electron acceptors and donors are well reproduced by the model, showing its ability to simulate transient competitive biodegradation. AU - Ballarini, E.* AU - Beyer, C.* AU - Bauer, R.D. AU - Griebler, C. AU - Bauer, S.* C1 - 31111 C2 - 34119 CY - New York SP - 351-371 TI - Model based evaluation of a contaminant plume development under aerobic and anaerobic conditions in 2D bench-scale tank experiments. JO - Biodegradation VL - 25 IS - 3 PB - Springer PY - 2013 SN - 0923-9820 ER -