scholarly journals Utilization of Phenol as Carbon Source by the Thermoacidophilic Archaeon Saccharolobus solfataricus P2 Is Limited by Oxygen Supply and the Cellular Stress Response

2021 ◽  
Vol 11 ◽  
Author(s):  
Jacqueline Wolf ◽  
Julia Koblitz ◽  
Andreas Albersmeier ◽  
Jörn Kalinowski ◽  
Bettina Siebers ◽  
...  
Keyword(s):  
Carbon Source ◽  
Genome Rearrangement ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Degradation Pathway ◽  
Cellular Stress Response ◽  
Stress Reactions ◽  
Phenol Biodegradation ◽  
Efficient Integration

Present in many industrial effluents and as common degradation product of organic matter, phenol is a widespread compound which may cause serious environmental problems, due to its toxicity to animals and humans. Degradation of phenol from the environment by mesophilic bacteria has been studied extensively over the past decades, but only little is known about phenol biodegradation at high temperatures or low pH. In this work we studied phenol degradation in the thermoacidophilic archaeon Saccharolobus solfataricus P2 (basonym: Sulfolobus solfataricus) under extreme conditions (80°C, pH 3.5). We combined metabolomics and transcriptomics together with metabolic modeling to elucidate the organism’s response to growth with phenol as sole carbon source. Although S. solfataricus is able to utilize phenol for biomass production, the carbon source induces profound stress reactions, including genome rearrangement as well as a strong intracellular accumulation of polyamines. Furthermore, computational modeling revealed a 40% higher oxygen demand for substrate oxidation, compared to growth on glucose. However, only 16.5% of oxygen is used for oxidation of phenol to catechol, resulting in a less efficient integration of carbon into the biomass. Finally, our data underlines the importance of the phenol meta-degradation pathway in S. solfataricus and enables us to predict enzyme candidates involved in the degradation processes downstream of 2-hydroxymucconic acid.

The highest inhibition coefficient of phenol biodegradation using an acclimated mixed culture

2015 ◽  
Vol 73 (5) ◽  
pp. 1033-1040 ◽  
Author(s):  
Mojtaba Mohseni ◽  
Payman Sharifi Abdar ◽  
S. Mehdi Borghei
Keyword(s):  
Mixed Culture ◽  
Degradation Rate ◽  
Growth Parameters ◽  
Removal Rate ◽  
Substrate Inhibition ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Phenol Biodegradation ◽  
Culture Substrate

In this study a membrane biological reactor (MBR) was operated at 25 ± 1 °C and pH = 7.5 ± 0.5 to treat synthetic wastewater containing high phenol concentrations. Removal efficiencies of phenol and chemical oxygen demand (COD) were evaluated at four various hydraulic retention times (HRTs) of 24, 12, 8, and 4 hours. The removal rate of phenol (5.51 kg-Phenol kg-VSS−1 d−1), observed at HRT of 4 h, was the highest phenol degradation rate in the literature. According to COD tests, there were no significant organic matter in the effluent, and phenol was degraded completely by mixed culture. Substrate inhibition was calculated from experimental growth parameters using the Haldane, Yano, and Edward equations. The results show that the Haldane equation is fitted to the experimental data in an excellent manner. Kinetic parameters were derived by nonlinear regression with a correlation coefficient (R2) of 0.974. The values for Haldane constants μmax, Ks, and Ki were 0.3085 h−1, 416 mg L−1 and 1,886 mg L−1, respectively. The Ki value is the highest value obtained for mixed cultures degrading phenol under batch conditions.

Electrochemical Degradation of Phenol Using the Oxygen Diffusion Cathode in an Undivided Cell

2011 ◽  
Vol 183-185 ◽  
pp. 575-579
Author(s):  
Hui Wang ◽  
Zhao Yong Bian ◽  
Guang Lu ◽  
Xiang Jia Wei ◽  
Xiu Juan Yu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Supporting Electrolyte ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Degradation Pathway ◽  
Phenol Removal ◽  
Electrochemical Degradation ◽  
Undivided Cell

Electrochemical degradation of phenol was studied in an undivided cell with a Ti/IrO2/RuO2 anode and a carbon/polytetrafluoroethylene (C/PTFE) O2-fed cathode which produced hydrogen peroxide (H2O2) by the electro-reduction of dissolved oxygen. The effect of current density, supporting electrolyte concentration and initial pH on the removal efficiency of phenol were investigated systematically. Results indicated that the optimal removal efficiency of phenol was achieved under the conditions of current density of 39 mA/cm2 and supporting electrolyte concentration of 0.02 mol/L. The phenol removal efficiency in the neutral condition was higher than that of acidic and basic conditions. The chemical oxygen demand (COD) and total organic carbon (TOC) removal achieved 71.6% and 63.6% for 100 min’s electrolysis, respectively. Benzoquinone, maleic acid, oxalic acid, acetic acid and formic acid were identified as intermediates by HPLC. A general phenol degradation pathway involving all these intermediates was proposed.

scholarly journals Assessment of Voltage Influence in Carbon Dioxide Fixation Process by a Photo-Bioelectrochemical System under Photoheterotrophy

2021 ◽  
Vol 9 (3) ◽  
pp. 474
Author(s):  
Sara Díaz-Rullo Edreira ◽  
Silvia Barba ◽  
Ioanna A. Vasiliadou ◽  
Raúl Molina ◽  
Juan Antonio Melero ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Source ◽  
Future Development ◽  
Metabolic Pathways ◽  
Co2 Fixation ◽  
Oxygen Demand ◽  
Carbon Uptake ◽  
Bioelectrochemical System ◽  
Electron Sink ◽  
Soluble Carbon

Bioelectrochemical systems are a promising technology capable of reducing CO2 emissions, a renewable carbon source, using electroactive microorganisms for this purpose. Purple Phototrophic Bacteria (PPB) use their versatile metabolism to uptake external electrons from an electrode to fix CO2. In this work, the effect of the voltage (from −0.2 to −0.8 V vs. Ag/AgCl) on the metabolic CO2 fixation of a mixed culture of PPB under photoheterotrophic conditions during the oxidation of a biodegradable carbon source is demonstrated. The minimum voltage to fix CO2 was between −0.2 and −0.4 V. The Calvin–Benson–Bassham (CBB) cycle is the main electron sink at these voltages. However, lower voltages caused the decrease in the current intensity, reaching a minimum at −0.8 V (−4.75 mA). There was also a significant relationship between the soluble carbon uptake in terms of chemical oxygen demand and the electron consumption for the experiments performed at −0.6 and −0.8 V. These results indicate that the CBB cycle is not the only electron sink and some photoheterotrophic metabolic pathways are also being affected under electrochemical conditions. This behavior has not been tested before in photoheterotrophic conditions and paves the way for the future development of photobioelectrochemical systems under heterotrophic conditions.

Isolation and Characterization of the Phenol Degradation Bacterium Diaphorobacter P2 Strain from Coking Wastewater

2012 ◽  
Vol 550-553 ◽  
pp. 2296-2300 ◽  
Author(s):  
Xiao Jun Meng ◽  
Yu Xiu Zhang ◽  
Rong Jia ◽  
Xia Li ◽  
Tuan Yao Chai ◽  
...  
Keyword(s):  
Orthogonal Experiment ◽  
Phenol Degradation ◽  
Morphological Properties ◽  
Coking Wastewater ◽  
Aerobic Bacterium ◽  
Metal Compounds ◽  
Phenol Biodegradation ◽  
Rdna Sequences ◽  
Isolation And Characterization ◽  
Peptone Medium

A aerobic bacterium strain P2 isolated from coking wastewater, was able to utilize phenol, o-cresol and pyridine as its sole carbon and energy source. The morphological properties and the phylogenetic analysis based on 16S rDNA sequences showed strain P2 belonged to the genus Diaphorobacter sp.. The optimum biodegradation of phenol was 37°C, pH 7.0-9.0 and 0.25% NaCl , respectively. The growth arrearage period was prolonged with the phenol concentration. The growth of Diaphorobacter P2 and phenol-degradation were inhibited completely by 50 μmol/L metal ions, such as Cu2 +, Ni2+, Cd2+ or Cr6+. Orthogonal experiment indicated the order of metal toxicity to biodegradation of P2 was Zn2+>Mn2+>Pb2+ under various heavy-metal compounds. The phenol biodegradation in coking wastewater supplemented with 2/3 beef extract peptone medium was degraded fully in 3 days, indicating that nutrient solution was beneficial for P2 growth and phenol degradation in wastewater. Those results suggest that the Diaphorobacter P2 has potential for treatment of coking wastewater.

Fenton degradation of Cartap hydrochloride: identification of the main intermediates and the degradation pathway

2015 ◽  
Vol 72 (7) ◽  
pp. 1198-1205 ◽  
Author(s):  
Kaixun Tian ◽  
Cuixiang Ming ◽  
Youzhi Dai ◽  
Kouassi Marius Honore Ake
Keyword(s):  
Aqueous Medium ◽  
Flue Gas ◽  
High Performance ◽  
Oxygen Demand ◽  
Nitrogen Monoxide ◽  
Degradation Pathway ◽  
Gas Chromatograph ◽  
Gas Analyzer ◽  
Fenton System ◽  
Long Chain

The advanced oxidation of Cartap hydrochloride (Cartap) promoted by the Fenton system in an aqueous medium was investigated. Based on total organic carbon, chemical oxygen demand and high-performance liquid chromatography, the oxidation of Cartap is quite efficient by the Fenton system. Its long chain is easily destroyed, but the reaction does not proceed to complete mineralization. Ion chromatography detection indicated the formation of acetic acid, propionic acid, formic acid, nitrous acid and sulfuric acid in the reaction mixtures. Further evidence of nitrogen monoxide and sulfur dioxide formation was obtained by using a flue gas analyzer. Monitoring by gas chromatograph-mass spectrometer demonstrated the formation of oxalic acid, ethanol, carbon dioxide, and l-alanine ethylamide. Based on these experimental results, plausible degradation pathways for Cartap mineralization in an aqueous medium by the Fenton system are proposed.

Novel biofilm reactor for denitrification of municipal wastewater

2018 ◽  
Vol 78 (7) ◽  
pp. 1566-1575 ◽  
Author(s):  
S. S. Rathnaweera ◽  
B. Rusten ◽  
K. Korczyk ◽  
B. Helland ◽  
E. Rismyhr
Keyword(s):  
Carbon Source ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Removal Rates ◽  
Good Filter ◽  
Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

scholarly journals Efficient Catalytic Degradation of Phenol with Phthalocyanine-Immobilized Reduced Graphene–Bacterial Cellulose Nanocomposite

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2218
Author(s):  
Binbin Wu ◽  
Yikai Sun ◽  
Qiujin Fan ◽  
Jiahui Chen ◽  
Weizheng Fang ◽  
...  
Keyword(s):  
Organic Acids ◽  
Bacterial Cellulose ◽  
Phenol Degradation ◽  
Academic Research ◽  
Oxygen Demand ◽  
Functional Materials ◽  
Degradation Ratio ◽  
Reduced Graphene ◽  
Ft Ir ◽  
Phenol Wastewater

In this report, phthalocyanine (Pc)/reduced graphene (rG)/bacterial cellulose (BC) ternary nanocomposite, Pc-rGBC, was developed through the immobilization of Pc onto a reduced graphene–bacterial cellulose (rGBC) nanohybrid after the reduction of biosynthesized graphene oxide-bacterial cellulose (GOBC) with N2H4. Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to monitor all of the functionalization processes. The Pc-rGBC nanocomposite was applied for the treatment of phenol wastewater. Thanks to the synergistic effect of BC and rG, Pc-rGBC had good adsorption capacity to phenol molecules, and the equilibrium adsorption data fitted well with the Freundlich model. When H2O2 was presented as an oxidant, phenol could rapidly be catalytically decomposed by the Pc-rGBC nanocomposite; the phenol degradation ratio was more than 90% within 90 min of catalytic oxidation, and the recycling experiment showed that the Pc-rGBC nanocomposite had excellent recycling performance in the consecutive treatment of phenol wastewater. The HPLC result showed that several organic acids, such as oxalic acid, maleic acid, fumaric acid, glutaric acid, and adipic acid, were formed during the reaction. The chemical oxygen demand (COD) result indicated that the formed organic acids could be further mineralized to CO2 and H2O, and the mineralization ratio was more than 80% when the catalytic reaction time was prolonged to 4 h. This work is of vital importance, in terms of both academic research and industrial practice, to the design of Pc-based functional materials and their application in environmental purification.

scholarly journals Comparison of aerobic processes for olive mill wastewater treatment

2020 ◽  
Vol 81 (9) ◽  
pp. 1914-1926 ◽  
Author(s):  
Y. Jaouad ◽  
M. Villain-Gambier ◽  
L. Mandi ◽  
B. Marrot ◽  
N. Ouazzani
Keyword(s):  
Stable State ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Olive Mill Wastewater ◽  
Organic Loading Rate ◽  
Efficient Technology ◽  
Treated Water ◽  
Conventional Activated Sludge ◽  
Olive Mill

Abstract Membrane bioreactor (MBR) has been proven to be an efficient technology capable of treating various industrial effluents. However, the evaluation of its performances in the case of olive mill wastewater (OMW) over a conventional activated sludge (CAS) have not been determined yet. The present study aims to compare OMW treatment in two laboratory scale pilots: an external ceramic MBR and CAS starting with an acclimation step in both reactors by raising OMW concentration progressively. After the acclimation step, the reactors received OMW at 2 gCOD/L with respect to an organic loading rate of 0.2 and 0.3 kgCOD/kgMLVSS/d for MBR and CAS, respectively. Biomass acclimation occurred successfully in both systems; however, the MBR tolerated more OMW toxicity than CAS as the MBR always maintained an effluent with a better quality. At a stable state, a higher reduction of 95% chemical oxygen demand (COD) was obtained with MBR compared to CAS (86%), but both succeeded in polyphenols removal (80%). Moreover, a higher MLSS elimination from the MBR treated water (97%) was measured against 88% for CAS. Therefore, CAS was suitable for OMW treatment and MBR could be proposed as an alternative to CAS when a better quality of treated water is required.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

Anaerobic Degradation of PCP and Phenol in Fixed-Film Reactors: The Influence of an Additional Substrate

1991 ◽  
Vol 24 (3-4) ◽  
pp. 431-436 ◽  
Author(s):  
H. V. Hendriksen ◽  
S. Larsen ◽  
B. K. Ahring
Keyword(s):  
Sewage Sludge ◽  
Carbon Source ◽  
Anaerobic Degradation ◽  
Degradation Products ◽  
Phenol Degradation ◽  
Treatment Plant ◽  
Continuous Operation ◽  
Mineral Medium ◽  
Fixed Film ◽  
Digested Sewage Sludge

The anaerobic degradation of pentachlorophenol (PCP) and phenol was examined in two lab-scale fixed-film reactors. Anaerobic digested sewage sludge from a municipal treatment plant was used as inoculum. The reactors were fed a mineral medium containing PCP (1-2 mg/l) and phenol (4-6 mg/l). In addition one of the reactors received 1 g/l glucose as an easily degradable carbon source. After 6 months of continuous operation, the removal of PCP in the reactor with no glucose added was approximately 60%, whereas the removal in the reactor with glucose reached 98%. Tetrachlorophenol (TeCP) and trichloro-phenol (TCP) were found as degradation products and the removal of these compounds was also significantly enhanced by the presence of glucose. Phenol degradation was approximately 70% with glucose added and 95% without glucose.

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