scholarly journals Fast Location and Isolation of Phenanthrene-degrading Halophilic Microbial Community and its Degradation Pathway

2021 ◽  
Author(s):  
Peng Peng ◽  
Linjie Yuan ◽  
Qing Li ◽  
Chaobei Wang ◽  
Taiming Shen ◽  
...  
Keyword(s):  
Phthalic Acid ◽  
High Salinity ◽  
Microbial Consortium ◽  
Treatment Plant ◽  
Degradation Pathway ◽  
Biodegradation Pathway ◽  
Blast Search ◽  
Metagenome Sequencing ◽  
Aerobic Sludge ◽  
Main Carbon

Abstract Microbial consortium WZ-4, which could degrade phenanthrene (PHE) as the main carbon and energy source, was isolated from the aerobic sludge of Weizhou wastewater treatment plant. Under the condition of high salinity (3%), the degradation of PHE (100 mg/L) was 87.76% in 7d. Its metabolites, genome sequence and biodegradation pathway were studied. The main metabolites include 1,2-dihydroxynaphthalene, 1-hydroxy-2-naphthalene, 5,6-benzocoumarin and phthalic acid. 12 PHE degrading enzyme genes appeared in the metagenome sequencing of WZ-4, and the genes involved in PHE degradation were included phdE, phdF, phdG, and pcaL. Based on the metabolites detected by GC-MS and the potential PHE-degrading genes identified by BLAST search, biodegradation pathway of PHE by WZ-4 was predicted.

Deemulsification of Water-in-Oil Emulsion with Sludges

1987 ◽  
Vol 22 (3) ◽  
pp. 437-443 ◽  
Author(s):  
N. Kosaric ◽  
Z. Duvnjak
Keyword(s):  
Activated Sludge ◽  
Room Temperature ◽  
Petroleum Refinery ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Activated Sludge Process ◽  
Sludge Treatment ◽  
Oil Emulsion ◽  
Water In Oil Emulsion ◽  
Aerobic Sludge

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.

scholarly journals Rhizospheric Microbiome Profiling of Capsicum annuum L. Cultivated in Amended Soils by 16S and Internal Transcribed Spacer 2 rRNA Amplicon Metagenome Sequencing

2017 ◽  
Vol 5 (30) ◽  
Author(s):  
Ali Asaff-Torres ◽  
Mariana Armendáriz-Ruiz ◽  
Manuel Kirchmayr ◽  
Raúl Rodríguez-Heredia ◽  
Marcos Orozco ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Internal Transcribed Spacer ◽  
Root Exudate ◽  
Microbial Consortium ◽  
Amended Soils ◽  
Internal Transcribed Spacer 2 ◽  
Capsicum Annuum L ◽  
Metagenome Sequencing ◽  
Microbiome Profiling

ABSTRACT Rhizospheric microbiomes of Capsicum annuum L. cultivated either conventionally or amended with a synthetic microbial consortium or a root exudate inductor, were characterized by 16S/internal transcribed spacer 2 (ITS2) rRNA amplicon metagenome sequencing. The most abundant taxa found, although differently represented in each treatment, were Gammaproteobacteria, Alphaproteobacteria, Actinobacteria, and Bacilli, as well as Chytridiomycetes and Mortierellomycotina.

scholarly journals Degradation of Anthracene by Mycobacterium sp. Strain LB501T Proceeds via a Novel Pathway, through o-Phthalic Acid

2003 ◽  
Vol 69 (1) ◽  
pp. 186-190 ◽  
Author(s):  
René van Herwijnen ◽  
Dirk Springael ◽  
Pieter Slot ◽  
Harrie A. J. Govers ◽  
John R. Parsons
Keyword(s):  
Energy Source ◽  
Type Strain ◽  
Phthalic Acid ◽  
Protocatechuic Acid ◽  
Wild Type Strain ◽  
Degradation Pathway ◽  
Wild Type ◽  
Catabolic Pathway ◽  
Naphthalene Degradation

ABSTRACT Mycobacterium sp. strain LB501T utilizes anthracene as a sole carbon and energy source. We analyzed cultures of the wild-type strain and of UV-generated mutants impaired in anthracene utilization for metabolites to determine the anthracene degradation pathway. Identification of metabolites by comparison with authentic standards and transient accumulation of o-phthalic acid by the wild-type strain during growth on anthracene suggest a pathway through o-phthalic acid and protocatechuic acid. As the only productive degradation pathway known so far for anthracene proceeds through 2,3-dihydroxynaphthalene and the naphthalene degradation pathway to form salicylate, this indicates the existence of a novel anthracene catabolic pathway in Mycobacterium sp. LB501T.

A Performance Study of Aerobic Sludge Digestion

1973 ◽  
Vol 8 (1) ◽  
pp. 26-35
Author(s):  
K.S. Hogg ◽  
J. Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Climatic Conditions ◽  
Anaerobic Sludge ◽  
Process Conditions ◽  
Performance Study ◽  
Digested Sludge ◽  
Sludge Digestion ◽  
Aerobic Sludge

Abstract The aerobic sludge digestion system at the sewage treatment plant at Dunnville, Ontario was designed as a one-stage aeration process (by means of the Inka system) of moderately concentrated excess activated sludge (less than 1 percent of TS), followed by continuous sludge thickening and sludge drying lagoons for the final dewatering of the digestion product. An evaluation of this system was conducted in the summer of 1972. It included the study of sludge and supernatant characteristics, phosphorus balance and an economical comparison of the costs associated with this type of aerobic digestion and anaerobic sludge digestion for similar size (about 1.7 IMGD) activated sludge process plants. Results of the investigations disclosed that the aerobic digester with sludge loading of about 0.03 lb VS/cu ft/day and an average hydraulic detention time of only 9.2 days, operated satisfactorily at the summer climatic conditions of Southern Ontario. This process, however, could not be judged on the basis of volatile solids reduction, which proved to be only equal to 6 percent. This phenomenon was probably due to the solubility in water of a part of the mineral constituents of the sludge under the process conditions. The change in the sludge specific oxygen uptake rates from 8.9 to 2.75 mg 02/gVSS/hr at 25°C, was a more reliable indicator of the digested sludge characteristics. Supernatant quality (average COD of 170 mg/l and SS of 110 mg/l) and the dewaterability of the digested sludge (average resistance to filtration equal to 0.86 x 1013 m/kg) provided additional information of the digester’s performance.

scholarly journals An Aerobic Hybrid Phthalate Degradation Pathway via Phthaloyl-Coenzyme A in Denitrifying Bacteria

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Christa Ebenau-Jehle ◽  
Christina I. S. L. Soon ◽  
Jonathan Fuchs ◽  
Robin Geiger ◽  
Matthias Boll
Keyword(s):  
Phthalic Acid ◽  
Coenzyme A ◽  
Anaerobic Bacteria ◽  
Degradation Pathway ◽  
Phthalic Acid Esters ◽  
Content Type ◽  
Facultatively Anaerobic ◽  
Oxygen Sensitive ◽  
Acid Esters ◽  
Facultatively Anaerobic Bacteria

ABSTRACT The degradation of the xenobiotic phthalic acid esters by microorganisms is initiated by the hydrolysis to the respective alcohols and ortho-phthalate (hereafter, phthalate). In aerobic bacteria and fungi, oxygenases are involved in the conversion of phthalate to protocatechuate, the substrate for ring-cleaving dioxygenases. In contrast, anaerobic bacteria activate phthalate to the extremely unstable phthaloyl-coenzyme A (CoA), which is decarboxylated by oxygen-sensitive UbiD-like phthaloyl-CoA decarboxylase (PCD) to the central benzoyl-CoA intermediate. Here, we demonstrate that the facultatively anaerobic, denitrifying Thauera chlorobenzoica 3CB-1 and Aromatoleum evansii KB740 strains use phthalate as a growth substrate under aerobic and denitrifying conditions. In vitro assays with extracts from cells grown aerobically with phthalate demonstrated the succinyl-CoA-dependent activation of phthalate followed by decarboxylation to benzoyl-CoA. In T. chlorobenzoica 3CB-1, we identified PCD as a highly abundant enzyme in both aerobically and anaerobically grown cells, whereas genes for phthalate dioxygenases are missing in the genome. PCD was highly enriched from aerobically grown T. chlorobenzoica cells and was identified as an identical enzyme produced under denitrifying conditions. These results indicate that the initial steps of aerobic phthalate degradation in denitrifying bacteria are accomplished by the anaerobic enzyme inventory, whereas the benzoyl-CoA oxygenase-dependent pathway is used for further conversion to central intermediates. Such a hybrid pathway requires intracellular oxygen homeostasis at concentrations low enough to prevent PCD inactivation but sufficiently high to supply benzoyl-CoA oxygenase with its cosubstrate. IMPORTANCE Phthalic acid esters (PAEs) are industrially produced on a million-ton scale per year and are predominantly used as plasticizers. They are classified as environmentally relevant xenobiotics with a number of adverse health effects, including endocrine-disrupting activity. Biodegradation by microorganisms is considered the most effective process to eliminate PAEs from the environment. It is usually initiated by the hydrolysis of PAEs to alcohols and o-phthalic acid. Degradation of o-phthalic acid fundamentally differs in aerobic and anaerobic microorganisms; aerobic phthalate degradation heavily depends on dioxygenase-dependent reactions, whereas anaerobic degradation employs the oxygen-sensitive key enzyme phthaloyl-CoA decarboxylase. We demonstrate that aerobic phthalate degradation in facultatively anaerobic bacteria proceeds via a previously unknown hybrid degradation pathway involving oxygen-sensitive and oxygen-dependent key enzymes. Such a strategy is essential for facultatively anaerobic bacteria that frequently switch between oxic and anoxic environments.

scholarly journals Aerobic Sludge Granulation in a Full-Scale Sequencing Batch Reactor

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Li ◽  
Li-Bin Ding ◽  
Ang Cai ◽  
Guo-Xian Huang ◽  
Harald Horn
Keyword(s):  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Granule Formation ◽  
Sludge Granulation ◽  
Aerobic Sludge ◽  
Raw Wastewater

Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR) with 50,000 m3 d−1for treating a town’s wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30of 47.1 mL g−1, diameter of 0.5 mm, and settling velocity of 42 m h−1were obtained. Compared to an anaerobic/oxic plug flow (A/O) reactor and an oxidation ditch (OD) being operated in this wastewater treatment plant, the sludge from full-scale SBR has more compact structure and excellent settling ability. Denaturing gradient gel electrophoresis (DGGE) analysis indicated thatFlavobacteriumsp., uncultured beta proteobacterium, unculturedAquabacteriumsp., and unculturedLeptothrixsp. were just dominant in SBR, whereas uncultured bacteroidetes were only found in A/O and OD. Three kinds of sludge had a high content of protein in extracellular polymeric substances (EPS). X-ray fluorescence (XRF) analysis revealed that metal ions and some inorganics from raw wastewater precipitated in sludge acted as core to enhance granulation. Raw wastewater characteristics had a positive effect on the granule formation, but the SBR mode operating with periodic feast-famine, shorter settling time, and no return sludge pump played a crucial role in aerobic sludge granulation.

scholarly journals Integrated multi-omics investigations reveal the key role of synergistic microbial networks in removing plasticizer di-(2-ethylhexyl) phthalate from estuarine sediments

2021 ◽  
Author(s):  
Sean Ting-Shyang Wei ◽  
Yi-Lung Chen ◽  
Yu-Wei Wu ◽  
Tien-Yu Wu ◽  
Yi-Li Lai ◽  
...  
Keyword(s):  
Phthalic Acid ◽  
Profile Analysis ◽  
Metabolite Profile ◽  
Degradation Pathway ◽  
Estuarine Sediments ◽  
Side Chain ◽  
Side Chains ◽  
Human Beings ◽  
Alkyl Side Chains ◽  
Ethylhexyl Phthalate

Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plasticizer worldwide with an annual global production of over eight million tons. Because of its improper disposal, endocrine-disrupting DEHP often accumulates in estuarine sediments in industrialized countries at sub-millimolar levels, resulting in adverse effects on both ecosystems and human beings. The microbial degraders and biodegradation pathways of DEHP in O2-limited estuarine sediments remain elusive. Here, we employed an integrated meta-omics approach to identify the DEHP degradation pathway and major degraders in this ecosystem. Estuarine sediments were treated with DEHP or its derived metabolites, o-phthalic acid and benzoic acid. The rate of DEHP degradation in denitrifying mesocosms was two times slower than that of o-phthalic acid, suggesting that side-chain hydrolysis of DEHP is the rate-limiting step of anaerobic DEHP degradation. On the basis of microbial community structures, functional gene expression, and metabolite profile analysis, we proposed that DEHP biodegradation in estuarine sediments is mainly achieved through synergistic networks between denitrifying proteobacteria. Acidovorax and Sedimenticola are the major degraders of DEHP side-chains; the resulting o-phthalic acid is mainly degraded by Aestuariibacter through the UbiD-dependent benzoyl-CoA pathway. We isolated and characterized Acidovorax sp. strain 210-6 and its extracellular hydrolase, which hydrolyzes both alkyl side-chains of DEHP. Interestingly, genes encoding DEHP/MEHP hydrolase and phthaloyl-CoA decarboxylase—key enzymes for side-chain hydrolysis and o-phthalic acid degradation, respectively—are flanked by transposases in these proteobacterial genomes, indicating that DEHP degradation capacity is likely transferred horizontally in microbial communities.

scholarly journals Arhodomonas sp. Strain Seminole and Its Genetic Potential To Degrade Aromatic Compounds under High-Salinity Conditions

2014 ◽  
Vol 80 (21) ◽  
pp. 6664-6676 ◽  
Author(s):  
Sonal Dalvi ◽  
Carla Nicholson ◽  
Fares Najar ◽  
Bruce A. Roe ◽  
Patricia Canaan ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
High Salinity ◽  
Sequence Similarity ◽  
Tca Cycle ◽  
Degradation Pathway ◽  
Rrna Gene ◽  
Content Type ◽  
Catabolic Genes ◽  
Benzene Toluene ◽  
Tca Cycle Intermediates

ABSTRACTArhodomonassp. strain Seminole was isolated from a crude oil-impacted brine soil and shown to degrade benzene, toluene, phenol, 4-hydroxybenzoic acid (4-HBA), protocatechuic acid (PCA), and phenylacetic acid (PAA) as the sole sources of carbon at high salinity. Seminole is a member of the genusArhodomonasin the classGammaproteobacteria, sharing 96% 16S rRNA gene sequence similarity withArhodomonas aquaeoleiHA-1. Analysis of the genome predicted a number of catabolic genes for the metabolism of benzene, toluene, 4-HBA, and PAA. The predicted pathways were corroborated by identification of enzymes present in the cytosolic proteomes of cells grown on aromatic compounds using liquid chromatography-mass spectrometry. Genome analysis predicted a cluster of 19 genes necessary for the breakdown of benzene or toluene to acetyl coenzyme A (acetyl-CoA) and pyruvate. Of these, 12 enzymes were identified in the proteome of toluene-grown cells compared to lactate-grown cells. Genomic analysis predicted 11 genes required for 4-HBA degradation to form the tricarboxylic acid (TCA) cycle intermediates. Of these, proteomic analysis of 4-HBA-grown cells identified 6 key enzymes involved in the 4-HBA degradation pathway. Similarly, 15 genes needed for the degradation of PAA to the TCA cycle intermediates were predicted. Of these, 9 enzymes of the PAA degradation pathway were identified only in PAA-grown cells and not in lactate-grown cells. Overall, we were able to reconstruct catabolic steps for the breakdown of a variety of aromatic compounds in an extreme halophile, strain Seminole. Such knowledge is important for understanding the role ofArhodomonasspp. in the natural attenuation of hydrocarbon-impacted hypersaline environments.

scholarly journals Research on Phthalic Acid Esters Removal and Its Health Risk Evaluation by Combined Process for Secondary Effluent of Wastewater Treatment Plant

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Simin Li ◽  
Yongkang Lv ◽  
Na Zhao
Keyword(s):  
Wastewater Treatment ◽  
Health Risk ◽  
Wastewater Treatment Plant ◽  
Phthalic Acid ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Phthalic Acid Esters ◽  
Combined Process ◽  
Acid Esters

This paper analyses the treatment effect of the “coagulation-sedimentation-O3-biological sand filtration-GAC” combined process on phthalic acid esters in secondary effluent of municipal wastewater treatment plant and meanwhile evaluate its health risk. The results indicated that when the concentrations of DBP and DiOP in secondary effluent were at range of 0.41 mg/L–0.814 mg/L and 0.23 mg/L–0.36 mg/L, the average total removal rates of DBP and DiOP were 85.10% and 68.11%, and the average concentration of DBP and DiOP in effluent were 0.089 mg/L and 0.091 mg/L, respectively. The quality of the effluent met the requirement of the ornamental scenic environment water inThe Quality of Urban Wastewater Recycling and Scenic Environment Water (GB/T 18921-2002), and the health risks of DBP and DiOP in effluent were at range of 1.99 × 10−12 –2.15 × 10−12/a and 1.48 × 10−11 –1.85 × 10−11/a, respectively, which is lower than the acceptable maximum risk level: 1.0 × 10−6.

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