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1.
Ecotoxicol Environ Saf ; 282: 116694, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38971101

RESUMO

In this study, a microcosm experiment was conducted to investigate the effects of Na2S2O8 preoxidation combined with biostimulation on petroleum-contaminated soil remediation. The response of microbial community during this process was explored using BIOLOG ECO microplate carbon utilization method and 16 s rDNA high-throughput sequencing. The results showed that use of 10 mg/g Na2S2O8 removed 19.8 % of the petroleum hydrocarbons, reduced soil biotoxicity and did not affect soil microbial activity compared to other concentrations. Therefore, sodium persulfate of ca. 10 mg/g was used to oxidize petroleum in soil before the biostimulation experiment with organic and inorganic fertilizers. Our finding showed that the content of total petroleum hydrocarbons (TPHs) in soil was reduced by 43.3 % in inorganic fertilizer treatment after 60 days. The results of BIOLOG ECO microplate carbon utilization analysis and 16 S rDNA high-throughput sequencing further confirmed that biostimulation quickly restored the microbial activities in oxidant treated soil. The main marker bacteria in chemical oxidation combined with biostimulation remediation were Arthrobacter and Paenarthrobacter, and their relative abundances were both significantly negatively correlated with the content of petroleum hydrocarbons in soil.


Assuntos
Biodegradação Ambiental , Oxirredução , Petróleo , Microbiologia do Solo , Poluentes do Solo , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Fertilizantes/análise , Sulfatos , Hidrocarbonetos , Compostos de Sódio/toxicidade , Solo/química , Arthrobacter , Recuperação e Remediação Ambiental/métodos , Bactérias/efeitos dos fármacos , Bactérias/genética
2.
Ecotoxicol Environ Saf ; 269: 115739, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38016191

RESUMO

The root-associated microbiome assembly substantially promotes (hyper)accumulator plant growth and metal accumulation and is influenced by multiple factors, especially host species and environmental stress. Athyrium wardii (Hook.) is a phytostabilizer that grows in lead (Pb)-zinc (Zn) mine tailings and shows high root Pb accumulation. However, there remains little information on the assembly of the root-associated microbiome of A. wardii and its role in phytostabilization. A field study investigated the structural and functional variation in the root-associated bacterial microbiome of Athyrium wardii (Hook.) exposed to different levels of contamination in Pb-Zn mine tailings. The root compartment dominated the variation in the root-associated bacterial microbiome but the levels of contaminants showed less impact. Bacterial co-occurrence was enhanced in the rhizosphere soil and rhizoplane but tended to be much simpler in the endosphere in terms of network complexity and connectivity. This indicates that the microbial community assembly of A. wardii was non-random and shaped by root selective effects. Proteobacteria, Chloroflexi, Actinobacteria, Cyanobacteria, and Acidobacteriota were generally the dominant bacterial phyla. The genera Crossiella and Bradyrhizobium were enriched in the rhizosphere and cyanobacterial genera were enriched in the endosphere, demonstrating substantial advantages to plant survival and adaptation in the harsh mine environment. Functional categories involved in amino acid and carbohydrate metabolism were abundant in the rhizosphere soil, thus contributing to metal solubility and bioavailability in the rhizosphere. Membrane transporters, especially ATP-binding cassette transporters, were enriched in the endosphere, indicating a potential role in metal tolerance and transportation in A. wardii. The study shows substantial variation in the structure and function of microbiomes colonizing different compartments, with the rhizosphere and endophytic microbiota potentially involved in plant metal tolerance and accumulation during phytostabilization.


Assuntos
Microbiota , Traqueófitas , Chumbo/toxicidade , Chumbo/metabolismo , Plantas , Bactérias , Zinco/toxicidade , Zinco/metabolismo , Solo/química , Rizosfera , Raízes de Plantas/metabolismo , Microbiologia do Solo
3.
Bull Environ Contam Toxicol ; 103(1): 140-146, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30600392

RESUMO

Para-chloronitrobenzene (p-CNB) in soil has posed significant health risks because of its persistence and high toxicity. The efficacy of catalyzed Zero-Valent Iron (ZVI), activated persulfate, and ZVI-persulfate processes for the degradation of p-CNB in soil was investigated. The p-CNB removal rate significantly increased from 10.8 to 90.1% with increased ZVI dosage from 0.1 mmol g-1 to 1.0 mmol g-1. The p-CNB removal increased with the decrease of initial pH and a removal efficiency of 85.3% was obtained at an initial pH value of 6.8 in combined system. The p-CNB removal rate in the single persulfate system and ZVI system was 36.5% and 60.2%, while the ZVI-persulfate system showed more sufficient p-CNB removal capacity and the removal rate of p-CNB was 88.7%. Scanning electron microscopy (SEM) and Electron paramagnetic resonance (EPR) was adopted in order to explore the degradation mechanism by ZVI-Persulfate system in soil.


Assuntos
Nitrobenzenos/química , Poluentes do Solo/química , Solo/química , Sulfatos/química , Poluentes Químicos da Água/química , Catálise , Ferro/química , Oxirredução
4.
Chemosphere ; 360: 142379, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38777200

RESUMO

Biodegradation is difficult at high temperatures due to the limited capacity of microorganisms to survive and function outside their optimum temperature range. Here, a thermophilic petroleum-degrading consortium was enriched from compost at a temperature of 55 °C. 16S rDNA and metagenomic techniques were used to analyze the composition of the consortium and the mechanisms of degradation. The consortium degraded 17000 mg total petroleum hydrocarbons (TPHs) L-1 with a degradation efficiency of 81.5% in 14 days. The consortium utilized a range of substrates such as n-hexadecane, n-docosane, naphthalene and pyrene and grew well over a wide range of pH (4-10) and salinity (0-90 g L-1). The hydrocarbon-degrading extremophilic consortium contained, inter alia, (relative abundance >1%) Caldibacillus, Geobacillus, Mycolicibacterium, Bacillus, Chelatococcus, and Aeribacillus spp. Metagenomic analysis was conducted to discover the degradation and environmental tolerance functional genes of the consortium. Two alkane hydroxylase genes, alkB and ladA, were found. A microcosm study shows that the consortium promoted the bioremediation of soil TPHs. The results indicate that the consortium may be a good candidate for the high-temperature bioremediation of petroleum-contaminated soils.


Assuntos
Bactérias , Biodegradação Ambiental , Metagenômica , Petróleo , Microbiologia do Solo , Poluentes do Solo , Petróleo/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Bactérias/metabolismo , Bactérias/genética , Bactérias/classificação , Consórcios Microbianos , Hidrocarbonetos/metabolismo , Poluição por Petróleo , Solo/química , RNA Ribossômico 16S/genética , Alcanos/metabolismo
5.
Sci Total Environ ; 904: 166759, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37659531

RESUMO

A bacterial consortium, termed WPB, was obtained from polycyclic aromatic hydrocarbons (PAHs) contaminated soil from a coking site. The consortium effectively degraded 100 mg L-1 pyrene by 94.8 % within 12 days. WPB was also able to degrade phenanthrene (98.3 %) and benzo[a]pyrene (24.6 %) in 12 days, while the individual isolates showed no PAHs degrading ability. Paracoccus sp. dominated the bacterial consortium (65.0-86.2 %) throughout the degradation process. Metagenomic sequencing reveals the proportion of sequences with xenobiotics biodegradation and metabolism increased throughout the degradation process indicating the great potential of WPB to degrade pollutants. The annotation of genes by metagenomic analysis help reconstruct the degradation pathways ("phthalate pathway" and "naphthalene degradation") and reveal how different bacteria contribute to the degradation process. Mycobacterium gilvum was found to carry nidAB genes that catalyze the first step of high-molecular-weight (HMW) PAHs in the degradation process despite Mycobacterium gilvum accounting for only 0.005-0.06 %. In addition, genomes of Paracoccus denitrificans and some other genera affiliated with Devosia, Pusillimonas caeni and Eoetvoesia caeni were successfully recovered and were found to carry genes responsible for the degradation of the intermediates of pyrene. These results enable further understanding of the metabolic patterns of pyrene-degrading consortia and provide direction for further cultivation and discovery of key players in complex microbial consortia.


Assuntos
Coque , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pirenos/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Poluentes do Solo/metabolismo
6.
Sci Total Environ ; 863: 160917, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36529394

RESUMO

Microbial communities are closely related to plant performance and numerous studies have shown their involvement with the growth and development of host plants, resistance to pathogen invasion and adaptation to environmental stress. Here we described in detail the ecological process of the microbial community assembly in hyperaccumulator plant Sedum plumbizincicola. We divided the microbiota into four ecological compartments (bulk soil, rhizosphere, root endosphere and aboveground endosphere). The results showed that host selection strongly controlled the aggregation of microbial community. So that microbes occupied different niches from the bulk soil to the aboveground endosphere, and bacterial diversity and network complexity decreased gradually. Soil types were the second influencing factor, especially for the microbial community in the root endosphere. The SourceTracker analysis further confirmed the vertical migration of microbes from bulk soil to aboveground endosphere. In addition, under the condition of heavy metal pollution, the microbial community of S. plumbizincicola tended to form a microbial pool dominated by Proteobacteria and Actinobacteria. Ellin6067, Sphingomonas, Ralstonia, SC-I-84_uncultured bacterium, Burkholderiaceae_Undibacterium and Pedosphaeraceae_uncultured bacterium etc. were identified as the vital biomarker taxa. Among these genera, the relative abundance of last three was significantly positively correlated with the activation and transfer of cadmium, and they mainly enriched in paddy soil. This study provides evidence for the mechanism by which the microbial community assembly occurs and experience for regulating the microbial community and increasing the accumulation efficiency of potentially toxic metals in S. plumbizincicola.


Assuntos
Microbiota , Sedum , Poluentes do Solo , Cádmio/análise , Solo , Biodegradação Ambiental , Poluentes do Solo/análise , Bactérias , Plantas , Raízes de Plantas/microbiologia
7.
Chemosphere ; 322: 138225, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36828103

RESUMO

Surfactant-enhanced bioremediation (SEBR) is frequently employed to clean up soil polluted with petroleum hydrocarbons, but few studies have focused on how surfactants affect microbial communities and different fractions of petroleum hydrocarbons, particularly in the field. Here, the surfactants sodium dodecyl benzene sulfonate (SDBS), alpha olefin sulfonate (AOS), Triton X-100 (TX-100), Tween80, and rhamnolipid were combined with the oil-degrading bacterium Pseudomonas sp. SB to remediate oil-contaminated soil in the laboratory. AOS gave the highest removal efficiency (65.1%) of total petroleum hydrocarbons (TPHs). Therefore, AOS was used in a field experiment with Pseudomonas sp. SB and the removal efficiency of TPHs and long-chain hydrocarbons C21-C40 reached 57.4 and 53.0%, respectively, significantly higher than the other treatments. During bioremediation the addition of Pseudomonas sp. SB significantly stimulated the growth of bacterial genera such as Alcanivorax, Luteimonas, Parvibaculum, Stenotrophomonas, and Pseudomonas and AOS further stimulated the growth of Sphingobacterium, Pseudomonas and Alcanivorax. This study validates the feasibility of surfactant-enhanced bioremediation in the field and partly reveals the mechanism of surfactant-enhanced bioremediation from the perspective of changes in different fractions of petroleum and microbial community dynamics.


Assuntos
Microbiota , Petróleo , Surfactantes Pulmonares , Poluentes do Solo , Biodegradação Ambiental , Tensoativos , Poluentes do Solo/análise , Microbiologia do Solo , Hidrocarbonetos , Pseudomonas , Alcenos , Bactérias , Solo
8.
Sci Total Environ ; 855: 159023, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36167126

RESUMO

Microplastic pollution is an issue of major environmental concern worldwide. Land-use type may affect the abundance, polymer types, and distribution characteristics of soil microplastics but their distribution remains unknown on the coastal plain of east China. Here, the abundance of microplastics in farmland (FL), plantation (P), and orchard/secondary forest (OSF) soils was determined on the east China coastal plain, and characteristics of the microplastics (shape, size, colour, and polymer composition) were analysed in soil samples collected from 33 sites. The average abundances of microplastics in FL, P, and OSF soils on the coastal plain of the east China coast were 185, 109, and 150 items kg-1, respectively. Small particles, fibres and transparent particles were the main characteristics of the microplastics observed. The polymer types were mainly PP and PET. The abundance of microplastics in farmland was positively correlated with population density in the study area. Therefore, agricultural activities associated with high population density are the main factors leading to the high abundance of microplastics in farmland soil.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos/análise , Solo , Monitoramento Ambiental , Poluentes Químicos da Água/análise , China
9.
J Hazard Mater ; 452: 131220, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37003001

RESUMO

Chlorinated aliphatic hydrocarbons (CAHs) are potentially toxic substances that have been detected in various contaminated environments. Biological elimination is the main technique of detoxifying CAHs in the contaminated sites, but the soil bacterial community at CAH-contaminated sites have been little investigated. Here, high-throughput sequencing analysis of soil samples from different depths (to 6 m depth) at an aged CAH-contaminated site has been conducted to investigate the community composition, function, and assembly of soil bacteria. The alpha diversity of the bacterial community significantly increased with increasing depth and bacterial community also became more convergent with increasing depth. Organohalide-respiring bacteria (OHRB) is considered keystone taxa to reduce the environmental stress of CAHs by reductive dechlorinate CAHs into nontoxic products, increases the alpha diversity of bacterial community and improves the stability of bacterial co-occurrence network. The high concentration of CAHs in deep soil and the stable anaerobic environment make deterministic processes dominate bacterial community assembly, while the topsoil is dominated by dispersal limitation. In general, CAHs at contaminated sites have a great impact on bacterial community, but the CAHs metabolic community acclimated in deep soil can reduce the environmental stress of CAHs, which provides foundation for the monitored natural attenuation technology in CAHs-contaminated sites.


Assuntos
Hidrocarbonetos Clorados , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Hidrocarbonetos Clorados/análise , Bactérias/genética , Hidrocarbonetos , Solo , Microbiologia do Solo
10.
Nat Food ; 4(10): 912-924, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37783790

RESUMO

Aluminium (Al) toxicity impedes crop growth in acidic soils and is considered the second largest abiotic stress after drought for crops worldwide. Despite remarkable progress in understanding Al resistance in plants, it is still unknown whether and how the soil microbiota confers Al resistance to crops. Here we found that a synthetic community composed of highly Al-resistant bacterial strains isolated from the rice rhizosphere increased rice yield by 26.36% in acidic fields. The synthetic community harvested rhizodeposited carbon for successful proliferation and mitigated soil acidification and Al toxicity through extracellular protonation. The functional coordination between plants and microbes offers a promising way to increase the usage of legacy phosphorus in topsoil. These findings highlight the potential of microbial tools for advancing sustainable agriculture in acidic soils.


Assuntos
Microbiota , Oryza , Solo , Fósforo , Alumínio/toxicidade , Produtos Agrícolas , Ácidos
11.
Chemosphere ; 291(Pt 3): 132912, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34785179

RESUMO

Hazardous oil sludge (OS) poses a great challenge to the environment, whereas conventional treatment methods (i.e., incineration or pyrolysis-incineration) are relatively less value-added and will bring about air pollution problems. To realize the high-value utilization of OS, catalytic co-pyrolysis with waste biomass to produce platform chemicals was studied using TG-FTIR and Py (pyrolyzer)-GC/MS methods. Results showed that for the non-catalytic co-pyrolysis of RH (rice husk) and OS, the main synergy on weight loss was the greatly lowered initial pyrolysis temperature of RH (for ∼55 °C) at the lower temperatures and the reduced weight loss ratio of OS (∼10-18 wt%) within the higher temperature range. ZSM-5 catalyst promoted the degradation of OS and RH mixtures at < 150 °C, yet showed minor effects on their weight loss at higher temperatures. The oxygenated and aliphatic compounds from non-catalytic co-pyrolysis were efficiently converted, resulting in an increased relative yield of aromatics to the highest of 46% and an elevated selectivity to BTX (as high as 60%). Despite the relatively short carbon chain length of OS components, ZSM-5 was proved effective to activate the OS pyrolysis products, thus enhancing the further aromatization reactions with biomass pyrolysis intermediates. This study provides a novel method for value-added co-utilization of hazardous OS waste and abundant biomass waste, and thus is beneficial to producing renewable chemicals while reducing the environment pollutant.


Assuntos
Pirólise , Esgotos , Biocombustíveis , Biomassa , Catálise , Temperatura Alta
12.
J Hazard Mater ; 433: 128802, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35366451

RESUMO

Zero-valent iron (ZVI) is widely used to mitigate environmental pollutants such as chlorinated pesticides through reductive reactions accompanied by extensive impacts on the soil microbial community. However, whether and how ZVI changes the biodegradation of target compounds remain poorly understood. Here, we monitor the fate of lindane using a 14C-labled tracer and evaluate the growth and functions of the bacterial community in ZVI-stressed conditions in a historically γ-hexachlorocyclohexane (lindane)-contaminated soil using a combination of isotopic (18O-H2O) and metagenomic methods. ZVI promoted the biomineralization of lindane in a dose-dependent manner. Soil bacteria were inhibited by amendment with ZVI during the initial stages of incubation (first three days) but recovered during the subsequent six weeks. Metagenomic study indicates that the todC1/bedC1 genes involved in the oxidation of dechlorinated lindane intermediates were upregulated in the 18O-labeled bacterial community but the presence of the lin genes responsible for lindane dechlorination was not confirmed. In addition, the benzoate biodegradation pathway that links to downstream catabolism of lindane was enhanced. These findings indicate successive chemical and biological degradation mechanisms underlying ZVI-enhanced lindane mineralization and provide a scientific basis for the inclusion of an extended bioremediation stage in the environmental application of ZVI materials.


Assuntos
Hexaclorocicloexano , Ferro , Biodegradação Ambiental , Ferro/química , Isótopos , Solo/química
13.
Chemosphere ; 286(Pt 2): 131750, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34352537

RESUMO

The remediation effects of hydrogen peroxide (H2O2) oxidation and surfactant-leaching alone or in combination on three typical oilfield sludges were studied. The removal efficiency of total petroleum hydrocarbons (TPHs) of Jidong, Liaohe and Jiangsu oil sludges by hydrogen peroxide oxidation alone was very poor (6.5, 6.8, and 3.4 %, respectively) but increased significantly (p < 0.05), especially of long-chain hydrocarbons, by combining the use of H2O2 with surfactants (80.0, 79.8 and 82.2 %, respectively). Oxidation combined with leaching may impair microbial activity and organic manure was therefore added to the treated sludges for biostimulation and the composition and function of the microbial community were studied. The addition of manure rapidly restored sludge microbial activity and significantly increased the relative abundance of some salt-tolerant and alkali-tolerant petroleum-degrading bacteria such as Corynebacterium, Pseudomonas, Dietzia and Jeotgalicoccus. Moreover, the relative abundance of two classic petroleum-degrading enzyme genes, alkane 1-monooxygenase and catechol 1, 2-dioxygenase, increased significantly.


Assuntos
Microbiota , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Peróxido de Hidrogênio , Petróleo/análise , Esgotos , Microbiologia do Solo , Poluentes do Solo/análise , Tensoativos
14.
Sci Total Environ ; 792: 148411, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465037

RESUMO

Biodegradation of soil contaminants may be promoted near plant roots due to the "rhizosphere effect" which may enhance microbial growth and activity. However, the effects of different plant cultivars within a single species on degradation remains unclear. Here, we evaluated the removal of soil total petroleum hydrocarbons (TPHs) by ten different cultivars of tall fescue grass (Festuca arundinacea L.) and their associated rhizosphere microbiomes. TPH removal efficiency across the ten different cultivars was not significantly correlated with plant biomass. Rhizing Star and Greenbrooks cultivars showed the maximum (76.6%) and minimum (62.2%) TPH removal efficiencies, respectively, after 120 days. Significant differences were observed between these two cultivars in the composition of rhizosphere bacterial and fungal communities, especially during the early stages (day 30) of remediation but the differences decreased later (day 90). Putative petroleum-degrading bacterial and fungal guilds were enriched in the presence of tall fescue. Moreover, the complexity of microbial networks declined in treatments with higher TPH removal efficiency. The relative abundances of saprotrophic fungi and putative genes alkB and C12O in bacetria involved in petroleum degradation increased, especially in the presence of Rhizing Star cultivar, and this was consistent with the TPH removal efficiency results. These results indicate the potential of tall fescue grass cultivars and their associated rhizosphere microbiomes to phytoremediate petroleum hydrocarbon-contaminated soils.


Assuntos
Festuca , Microbiota , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
15.
Environ Geochem Health ; 32(1): 23-9, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19363671

RESUMO

In situ bioremediation of oily sludge-contaminated soil by biostimulation of indigenous microbes through adding manure was conducted at the Shengli oilfield in northern China. After bioremediation for 360 days, total petroleum hydrocarbon (TPH) content was reduced by 58.2% in the treated plots compared with only 15.6% in the control plot. Moreover, bioremediation significantly improved the physicochemical properties of the soil in the treated plot. Soil microbial counts and community-level physiological profiling were also examined. Manure addition increased TPH degraders and polycyclic aromatic hydrocarbon (PAH) degraders in the contaminated soil by one to two orders of magnitude. The activity and biodiversity of soil microbial communities also increased markedly in the treated plot compared with that of the control. Finally, biotoxicity was used to evaluate the soils and a sharp increase in the EC50 of the soil after bioremediation was observed, indicating that bioremediation had reduced the toxicity of the soil.


Assuntos
Bactérias/metabolismo , Petróleo/análise , Poluentes do Solo/análise , Biodegradação Ambiental , Biodiversidade , Contagem de Colônia Microbiana , Monitoramento Ambiental , Cinética , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade
16.
Chemosphere ; 248: 125983, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32004887

RESUMO

In this study, derivatives of two common fatty acids in plant root exudates, sodium palmitate and sodium linoleate (sodium aliphatates), were added to an aged Polycyclic aromatic hydrocarbons (PAHs) contaminated soil to estimate their effectiveness in the removal of PAHs. Sodium linoleate was more effective in lowering PAHs and especially high-molecular-weight (4-6 ring) PAHs (HMW-PAHs). Principal coordinates analysis (PCoA) indicates that both amendments led to a shift in the soil bacterial community. Moreover, linear discriminant effect size (LEfSe) analysis demonstrates that the specific PAHs degraders Pseudomonas, Arenimonas, Pseudoxanthomonas and Lysobacter belonging to the γ-proteobacteria and Nocardia and Rhodococcus belonging to the Actinobacteria were the biomarkers of, respectively, sodium linoleate and sodium palmitate amendments. Correlation analysis suggests that four biomarkers in the sodium linoleate amendment treatment from γ-proteobacteria were all highly linearly negatively related to HMW-PAHs residues (p < 0.01) while two biomarkers in the sodium palmitate amendment treatment from Actinobacteria were highly linearly negatively related to LMW-PAHs residues (p < 0.01). Higher removal efficiency of PAHs (especially HMW-PAHs) in the sodium linoleate amendment treatment than in the sodium palmitate amendment treatment might be ascribed to the specific enrichment of microbes from the γ-proteobacteria. The bacterial functional KEGG orthologs (KOs) assigned to PAHs metabolism and functional C23O and C12O genes related to cleavage of the benzene ring were both up-regulated. These results provide new insight into the mechanisms of the two sodium aliphatate amendments in accelerating PAHs biodegradation and have implications for practical application in the remediation of PAHs-contaminated soils.


Assuntos
Recuperação e Remediação Ambiental , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Actinobacteria/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Ácidos Graxos/metabolismo , Gammaproteobacteria/metabolismo , Microbiota , Raízes de Plantas/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo/química , Poluentes do Solo/análise
17.
Sci Total Environ ; 730: 139116, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32402971

RESUMO

Bacteria are critical ecosystem drivers in both aquatic and terrestrial ecosystems. However, our understanding of the mechanisms generating and maintaining biodiversity on large spatial scales remains limited, especially mechanisms involving rare taxa in soil ecosystems. In the present study we took paddy soils in China as model ecosystems and studied the ecological diversity and assembly mechanisms of both the rare and abundant bacterial subcommunities. We collected 339 paddy soil samples from 113 sites across 19 Chinese provinces that span distances of up to 3869 km. The bacterial community was characterized by high-throughput sequencing of the 16S rRNA gene. The α-diversity of rare and abundant subcommunities showed opposite quadratic correlations with the key environmental factor soil pH. Rare taxa exhibited a stronger distance-decay relationship than the abundant subcommunity. Moreover, deterministic selection processes dominated in the assembly of the abundant subcommunity while stochastic processes dominated in that of the rare subcommunity based on both variation partitioning analysis and the phylogenetic null model. Soil pH was also the main deterministic factor driving the geographical distributions of both the rare and abundant subcommunity. Besides, mean annul temperature and soil texture were also found to be important factors affecting the biogeography and diversity patterns of abundant and rare subcommunities. These results indicate that the mechanisms generating and maintaining the diversity of the abundant and rare subcommunities were totally different in paddy soils, suggesting that these two subcommunities may respond differently to future environmental change.


Assuntos
Oryza , Solo , Bactérias , China , Ecossistema , Filogenia , RNA Ribossômico 16S , Microbiologia do Solo
18.
J Hazard Mater ; 161(1): 479-84, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-18572312

RESUMO

Field-scale bioremediation of oily sludge in prepared beds was studied at Shengli oilfield in northern China. The influence of manure, coarse sand, sawdust, a specialized microbial preparation and greenhouse conditions on the efficiency of removal of oil and grease was evaluated. After bioremediation for 230d, oil and grease content fell by 32-42gkg(-1)dry sludge in treated plots, indicating removal of 27-46% compared with only 15% in the control plot. Addition of manure, coarse sand, sawdust and greenhouse conditions significantly (p<0.05) increased the amount removed. Moreover, the physico-chemical properties of the sludge in all treated plots improved significantly after bioremediation. Microbial biomass in sludge and community-level physiological profiling examined using BIOLOG microplates was also studied. Total petroleum hydrocarbon degraders and polycyclic aromatic hydrocarbon degraders increased in all treated oily sludge. The activity of sludge microbial communities increased markedly in the treated plots compared with the control. Canonical correspondence analysis showed that differences in substrate utilization patterns were highly correlated (p<0.05) with sludge hydrolyzable N and oil and grease content. The biological toxicity of the oily sludge was lower following bioremediation in most of the treated plots as evaluated using Photobacterium phosphoreum T3.


Assuntos
Indústrias Extrativas e de Processamento/métodos , Óleos/metabolismo , Petróleo/metabolismo , Esgotos/química , Biodegradação Ambiental , Biomassa , China , Esgotos/microbiologia
19.
Chemosphere ; 224: 265-271, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30825852

RESUMO

Two common organic wastes from agriculture (rice straw) and forestry (sawdust) were applied to a petroleum-contaminated soil to estimate their effectiveness in the removal of total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs). Rice straw was the more effective amendment than the other treatments in reducing TPH contents and addition of sawdust resulted in a significant decrease in PAH removal, particularly high-molecular-weight (5-6 ring) PAHs. Principal coordinates analysis (PCoA) indicates that rice straw treatment separated only the bacterial community but sawdust greatly affected both the soil bacterial and fungal communities. Moreover, the abundance of some petroleum degraders such as the bacteria Sphingomonas, Idiomarina and Phenylobacterium and the fungi Humicola, Wallemia and Graphium was promoted by inputs of the two agricultural and forestry wastes. These results highlight the potential of waste applications in accelerating hydrocarbon biodegradation which may be attributed to the enrichment of keystone taxa that show strong positive associations with hydrocarbon degradation.


Assuntos
Microbiota , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Oryza/química , Brotos de Planta/química , Madeira/química
20.
Chemosphere ; 225: 200-208, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30875503

RESUMO

Currently, Pb pollution has become a severe environmental problem and filamentous fungi hold a promising potential for the treatment of Pb-containing wastewater. The present study showed that the strain Pleurotus ostreatus ISS-1 had a strong ability to tolerate Pb at high concentration and reached a removal rate of 53.7% in liquid media. Pb was removed by extracellular biosorption, intracellular bioaccumulation by mycelia, or precipitation with extracellular oxalic acids. On the cellular level, Pb was mainly distributed in the cell wall, followed by vacuoles and organelles. Fourier transform infrared spectroscopy (FTIR) analysis indicated that hydroxyl, amides, carboxyl, and sulfhydryl groups provided binding sites for Pb. Furthermore, Pb was found on the cell surface in the form of PbS and PbCO3 through X-ray diffraction (XRD). Intracellular chelates such as thiol compounds and oxalic acid, as well as extracellular oxalic acid, might play an important role in the tolerance of Pb. In addition, isobaric tags for relative and absolute quantitation (iTRAQ) analysis showed that ATP-binding cassette (ABC) transporter, cytochrome P450, peroxisome, and the calcium signaling pathway might participate in both accumulation and detoxification of Pb. These results have successfully provided a basis for further developing Pb polluted water treatment technology by fungi.


Assuntos
Chumbo/isolamento & purificação , Chumbo/toxicidade , Pleurotus/efeitos dos fármacos , Pleurotus/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/toxicidade , Adsorção , Chumbo/metabolismo , Oxirredução , Águas Residuárias/química , Poluentes Químicos da Água/metabolismo
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