Removal of PAHs at high concentrations in a soil washing solution containing TX-100 via simultaneous sorption and biodegradation processes by immobilized degrading bacteria in PVA-SA hydrogel beads

2020 ◽  
pp. 124533
Author(s):  
Weixiao Chen ◽  
Haiyun Zhang ◽  
Meng Zhang ◽  
Xiaofang Shen ◽  
Xinyu Zhang ◽  
...  
Keyword(s):  
Soil Washing ◽  
Hydrogel Beads ◽  
Degrading Bacteria ◽  
High Concentrations ◽  
Simultaneous Sorption

Degradation of phenol at high concentrations using immobilization of Pseudomonas putida P53 into sawdust entrapped in sodium-alginate beads

2019 ◽  
Vol 79 (7) ◽  
pp. 1387-1396 ◽  
Author(s):  
Moslem Abarian ◽  
Mehdi Hassanshahian ◽  
Akramsadat Esbah
Keyword(s):  
Sodium Alginate ◽  
Bacterial Biomass ◽  
Alginate Beads ◽  
Free Form ◽  
Sem Images ◽  
Phenol Biodegradation ◽  
Degrading Bacteria ◽  
The Matrix ◽  
High Concentrations ◽  
Positive Results

Abstract Phenols are distributed either as natural or artificial mono-aromatic compounds in various environmental sites as major pollutants. The objective of this study was the immobilization of the phenol degrading bacteria P. putida P53 and A. scleromae P69 in sodium-alginate beads and sawdust as carriers and evaluate the biodegradation ability. The biodegradation ability of strains in free form were evaluated and P. putida P53 was shown to biodegrade up to 1,800 mg/L phenol. Bacterial biomass was prepared and attached to carrier with entrapment and attachment methods. Prepared beads were added to Erlenmeyer flasks containing different concentrations of phenol in BH medium (1,800, 2,200, 2,600 and 3,000 mg/L). According to the results, phenol biodegradation efficiency of immobilized bacteria in sawdust was more than free form. Strain P53 had better biodegradation than P69 strain. Attachment and entrapments into carriers had positive results, Scanning electron micrograph (SEM) images indicated that alginate beads were globular shapes (10 nm), and strains aggregated between the large cavities of the matrix. Comparison of sawdust and alginate as carriers for degradation of phenol at high concentrations demonstrated that sawdust improved biodegradation better, and immobilized P53 into sawdust entrapped in sodium-alginate beads can be used for biodegradation purposes.

scholarly journals Comparing Metabolic Functionalities, Community Structures, and Dynamics of Herbicide-Degrading Communities Cultivated with Different Substrate Concentrations

2012 ◽  
Vol 79 (1) ◽  
pp. 367-375 ◽  
Author(s):  
Erkin Gözdereliler ◽  
Nico Boon ◽  
Jens Aamand ◽  
Karen De Roy ◽  
Michael S. Granitsiotis ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Nucleic Acid Content ◽  
Cell Physiology ◽  
Rrna Gene ◽  
Low Concentrations ◽  
Degrading Bacteria ◽  
Gradient Gel Electrophoresis ◽  
Herbicide Concentration ◽  
Single Cell Physiology ◽  
High Concentrations

ABSTRACTTwo 4-chloro-2-methylphenoxyacetic acid (MCPA)-degrading enrichment cultures selected from an aquifer on low (0.1 mg liter−1) or high (25 mg liter−1) MCPA concentrations were compared in terms of metabolic activity, community composition, population growth, and single cell physiology. Different community compositions and major shifts in community structure following exposure to different MCPA concentrations were observed using both 16S rRNA gene denaturing gradient gel electrophoresis fingerprinting and pyrosequencing. The communities also differed in their MCPA-mineralizing activities. The enrichments selected on low concentrations mineralized MCPA with shorter lag phases than those selected on high concentrations. Flow cytometry measurements revealed that mineralization led to cell growth. The presence of low-nucleic acid-content bacteria (LNA bacteria) was correlated with mineralization activity in cultures selected on low herbicide concentrations. This suggests that LNA bacteria may play a role in degradation of low herbicide concentrations in aquifers impacted by agriculture. This study shows that subpopulations of herbicide-degrading bacteria that are adapted to different pesticide concentrations can coexist in the same environment and that using a low herbicide concentration enables enrichment of apparently oligotrophic subpopulations.

Response of cold-adapted microbial populations in a permafrost profile to hydrocarbon contaminants

Polar Record ◽  
2001 ◽  
Vol 37 (202) ◽  
pp. 239-248 ◽  
Author(s):  
A.G. Rike ◽  
M. Børresen ◽  
A. Instanes
Keyword(s):  
Microbial Populations ◽  
Contaminated Site ◽  
Permafrost Soil ◽  
Limiting Factor ◽  
Cold Adapted ◽  
Degrading Bacteria ◽  
Population Sizes ◽  
Different Depths ◽  
High Concentrations

AbstractHeterotrophic and hydrocarbon-degrading microbial populations in soils from different depths in a permafrost soil profile at a hydrocarbon-contaminated site at Ny-Ålesund, Svalbard, were examined and compared to the populations present at a pristine site. The objective was to investigate whether the populations were enhanced after 12 years of exposure to hydrocarbons. Based on air and soil temperature data, it is concluded that the microorganisms living in these environments are cold-adapted. Proliferation of the populations by a factor of 100–1000 was measured in the layers where mineral oil was present in high concentrations. This indicates that the populations responded to the additional carbon source by degradation and growth on hydrocarbons or hydrocarbon metabolites. A high number of intrinsic heterotrophic and hydrocarbon-degrading bacteria is a prerequisite forin situbioremediation of contaminated sites. Although the hydrocarbon-degrading activities of the populations are not known, the results show that the population sizes probably do not represent the limiting factor in a bioremedial action at this contaminated Arctic permafrost site.

scholarly journals Metagenomic Analysis for Evaluating Change in Bacterial Diversity in TPH-Contaminated Soil after Soil Remediation

Toxics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 319
Author(s):  
Jin-Wook Kim ◽  
Young-Kyu Hong ◽  
Hyuck-Soo Kim ◽  
Eun-Ji Oh ◽  
Yong-Ha Park ◽  
...  
Keyword(s):  
Soil Remediation ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Soil Bacteria ◽  
Bacterial Species ◽  
Soil Washing ◽  
Alpha Diversity ◽  
Metagenomic Analysis ◽  
Degrading Bacteria ◽  
The Impact

Soil washing and landfarming processes are widely used to remediate total petroleum hydrocarbon (TPH)-contaminated soil, but the impact of these processes on soil bacteria is not well understood. Four different states of soil (uncontaminated soil (control), TPH-contaminated soil (CS), after soil washing (SW), and landfarming (LF)) were collected from a soil remediation facility to investigate the impact of TPH and soil remediation processes on soil bacterial populations by metagenomic analysis. Results showed that TPH contamination reduced the operational taxonomic unit (OTU) number and alpha diversity of soil bacteria. Compared to SW and LF remediation techniques, LF increased more bacterial richness and diversity than SW, indicating that LF is a more effective technique for TPH remediation in terms of microbial recovery. Among different bacterial species, Proteobacteria were the most abundant in all soil groups followed by Actinobacteria, Acidobacteria, and Firmicutes. For each soil group, the distribution pattern of the Proteobacteria class was different. The most abundant classed were Alphaproteobacteria (16.56%) in uncontaminated soils, Deltaproteobacteria (34%) in TPH-contaminated soils, Betaproteobacteria (24%) in soil washing, and Gammaproteobacteria (24%) in landfarming, respectively. TPH-degrading bacteria were detected from soil washing (23%) and TPH-contaminated soils (21%) and decreased to 12% in landfarming soil. These results suggest that soil pollution can change the diversity of microbial groups and different remediation techniques have varied effective ranges for recovering bacterial communities and diversity. In conclusion, the landfarming process of TPH remediation is more advantageous than soil washing from the perspective of bacterial ecology.

scholarly journals Genetic and physiological characterisation of phenol- and p-cresol-degrading bacteria selected for bioaugmentation in oil- and phenol-polluted area

2019 ◽  
pp. 441-449
Author(s):  
Merike Merimaa ◽  
Eeva Heinaru ◽  
Merit Lehiste ◽  
Signe Viggor ◽  
Ain Heinaru
Keyword(s):  
Phenolic Compounds ◽  
Culture Conditions ◽  
Polluted Area ◽  
Donor Strain ◽  
Bacterial Strains ◽  
Catabolic Activity ◽  
Catabolic Genes ◽  
Degrading Bacteria ◽  
High Concentrations ◽  
Set Up

Successful bioaugmentation requires that bacterial strains introduced into the polluted area must be able to adapt to new environmental conditions and retain high enough catabolic activity. The strains should degrade pollutant present at high concentrations, while having high affinity for the pollutants for their thorough degradation. The transfer of genetic information from introduced donor strain to indigenous bacterial population increases the biodegradation potential. As laboratory-selected strains can be poor survivors and lose catabolic activity in mixed microbial ecosystems, the indigenous biodegradative strains isolated from the river water continuously polluted with phenolic compounds of oil shale leachate may serve as inoculants for bioaugmentation. We have shown that the native phenol- and p-cresol-degrading community could be grouped according to the presence of catabolic genes involved in catabolism of aromatic compounds. The selected representative strains of different catabolic types of degradation of phenol and p-cresol were identified as Pseudomonas mendocina (strain PCl) and P. jluorescens (strains PC! 8, PC24). Catabolic potential of these strains was studied on the basis of phenol hydroxylase, p-cresol methylhydroxylase and catechol 2,3-dioxygenase genes. The occurrence and conjugation of plasmid DNA were revealed in these strains. The ability of the selected strains to degrade several phenolic compounds in natural phenolic wastewater in which the compounds were present in multicomponent mixtures, was investigated through laboratory microcosm studies, To elucidate the extent of interactions among the used bacterial strains single and mixed cultures were set up. The biodegradation activity of strains in microcosms was examined through viable counts, consumption of phenolic compounds and detecting the presence of catabolic genes by hybridization, During the experiments (30 days) the introduced bacteria remained viable even when the substrates were depleted. The mixture of strains was more effective in the decomposition of phenolic compounds from the natural wastewater as compared with the single culture conditions and the metabolic activity and cell density of each strain were co-ordinated within a specific time scale. The behaviour of strains in the phenolic leachate depended on the growth kinetics of the strains (K,,µ).

scholarly journals Bioaugmentation of Native Fungi, an Efficient Strategy for the Bioremediation of an Aged Industrially Polluted Soil With Heavy Hydrocarbons

2021 ◽  
Vol 12 ◽  
Author(s):  
María Cecilia Medaura ◽  
Miriam Guivernau ◽  
X. Moreno-Ventas ◽  
Francesc X. Prenafeta-Boldú ◽  
Marc Viñas
Keyword(s):  
Vibrio Fischeri ◽  
Climatic Conditions ◽  
Polluted Soil ◽  
Total Petroleum Hydrocarbons ◽  
Hydrocarbon Biodegradation ◽  
Soil Bioremediation ◽  
Degrading Bacteria ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Native Fungi

The concurrence of structurally complex petroleum-associated contaminants at relatively high concentrations, with diverse climatic conditions and textural soil characteristics, hinders conventional bioremediation processes. Recalcitrant compounds such as high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) and heavy alkanes commonly remain after standard soil bioremediation at concentrations above regulatory limits. The present study assessed the potential of native fungal bioaugmentation as a strategy to promote the bioremediation of an aged industrially polluted soil enriched with heavy hydrocarbon fractions. Microcosms assays were performed by means of biostimulation and bioaugmentation, by inoculating a defined consortium of six potentially hydrocarbonoclastic fungi belonging to the genera Penicillium, Ulocladium, Aspergillus, and Fusarium, which were isolated previously from the polluted soil. The biodegradation performance of fungal bioaugmentation was compared with soil biostimulation (water and nutrient addition) and with untreated soil as a control. Fungal bioaugmentation resulted in a higher biodegradation of total petroleum hydrocarbons (TPH) and of HMW-PAHs than with biostimulation. TPH (C14-C35) decreased by a 39.90 ± 1.99% in bioaugmented microcosms vs. a 24.17 ± 1.31% in biostimulated microcosms. As for the effect of fungal bioaugmentation on HMW-PAHs, the 5-ringed benzo(a)fluoranthene and benzo(a)pyrene were reduced by a 36% and 46%, respectively, while the 6-ringed benzoperylene decreased by a 28%, after 120 days of treatment. Biostimulated microcosm exhibited a significantly lower reduction of 5- and 6-ringed PAHs (8% and 5% respectively). Higher TPH and HMW-PAHs biodegradation levels in bioaugmented microcosms were also associated to a significant decrease in acute ecotoxicity (EC50) by Vibrio fischeri bioluminiscence inhibition assays. Molecular profiling and counting of viable hydrocarbon-degrading bacteria from soil microcosms revealed that fungal bioaugmentation promoted the growth of autochthonous active hydrocarbon-degrading bacteria. The implementation of such an approach to enhance hydrocarbon biodegradation should be considered as a novel bioremediation strategy for the treatment of the most recalcitrant and highly genotoxic hydrocarbons in aged industrially polluted soils.

scholarly journals Molecular Diversity of Chlorpyrifos Degrading Bacteria Isolated from Apple Orchard Soils of Himachal Pradesh

2021 ◽  
Author(s):  
Anish Kumar Sharma ◽  
Jyotsana Pandit ◽  
Khyati Harkhani
Keyword(s):  
Molecular Diversity ◽  
Enrichment Culture ◽  
Biochemical Properties ◽  
Culture Technique ◽  
Apple Orchard ◽  
Bacterial Isolates ◽  
Degrading Bacteria ◽  
Pure Cultures ◽  
High Concentrations ◽  
Orchard Soils

A total of seventy-two bacterial isolates were obtained employing enrichment culture technique from apple orchard soils contaminated with chlorpyrifos. Pure cultures of bacterial isolates were obtained using streak plate method on mineral salt medium. Bacterial isolates were characterized on the basis of morphology, culture and biochemical properties. Six bacterial isolates exhibited high extracellular organophosphorus hydrolase activity along with high tolerance towards high concentrations of chlorpyrifos. Genomic DNA extraction from bacterial isolates was done with phenol/chloroform method. Molecular Diversity of six chlorpyrifos degrading bacterial isolates was done employing RAPD-PCR technique by using 25 decamer primers, where amplification was showed by only 20 primers. A total of 337 amplified bands and 64 unique bands ranging in size from 100 to 4900bps were produced after RAPD analysis. The similarity coefficient estimated by Jaccard’s coefficient for these bacterial isolates was found to range between 31 to 64 percent.

Development of a groundwater biobarrier for the removal of polycyclic aromatic hydrocarbons, BTEX, and heterocyclic hydrocarbons

2008 ◽  
Vol 58 (7) ◽  
pp. 1349-1355 ◽  
Author(s):  
A. Tiehm ◽  
A. Müller ◽  
S. Alt ◽  
H. Jacob ◽  
H. Schad ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Full Scale ◽  
Permeable Reactive Barrier ◽  
Column Studies ◽  
Degrading Bacteria ◽  
Polycyclic Aromatic ◽  
Tar Oil ◽  
High Concentrations ◽  
The City

A full scale funnel-and-gate biobarrier has been developed for the removal of tar oil pollutants at an abandoned tar factory site near the city of Offenbach, Germany. Laboratory and on-site column studies were done to determine the operation parameters for microbiological clean-up of the groundwater polluted with 12,000 μg/L mono- aromatic hydrocarbons such as benzene and the xylenes, 4,800 μg/L polycyclic aromatic hydrocarbons such as naphthalene and acenaphthene, and 4,700 μg/L heterocyclic aromatic hydrocarbons such as benzofuran and benzothiophene. In the laboratory study, a residence time of approx. 70 h proved to be sufficient for aerobic pollutant biodegradation. Up to 180 mg/L H2O2 were added and did not lead to any toxic effects to the degrading bacteria. The feasibility of the concept was confirmed in an on-site pilot study performed with a sedimentation tank (removal of ferric iron) and two bioreactors. In the bioreactors, >99.3% of the pollutants were degraded. Biodegradation activity corresponded to a significant increase in numbers of pollutant degrading bacteria. In the bioreactors, a fast dissociation of H2O2 was observed resulting in losses of oxygen and temporary gas clogging. Therefore, a repeated addition of moderate concentrations of H2O2 proved to be more favourable than the addition of high concentrations at a single dosing port. The full scale biobarrier consists of three separated bioreactors thus enabling extended control and access to the reactors. The operation of the funnel-and-gate biobarrier started in April 2007, and represents the first biological permeable reactive barrier with extended control (EC-PRB) in Germany.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

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