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1.
J Environ Manage ; 355: 120508, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38457896

RESUMO

Crude oil contamination has inflicted severe damage to soil ecosystems, necessitating effective remediation strategies. This study aimed to compare the efficacy of four different techniques (biostimulation, bioaugmentation, bioaugmentation + biostimulation, and natural attenuation) for remediating agricultural soil contaminated with crude oil using soil microcosms. A consortium of previously characterized bacteria Xanthomonas boreopolis, Microbacterium schleiferi, Pseudomonas aeruginosa, and Bacillus velezensis was constructed for bioaugmentation. The microbial count for the constructed consortium was recorded as 2.04 ± 0.11 × 108 CFU/g on 60 d in augmented and stimulated soil samples revealing their potential to thrive in chemically contaminated-stress conditions. The microbial consortium through bioaugmentation + biostimulation approach resulted in 79 ± 0.92% degradation of the total polyaromatic hydrocarbons (2 and 3 rings âˆ¼ 74%, 4 and 5 rings âˆ¼ 83% loss) whereas, 91 ± 0.56% degradation of total aliphatic hydrocarbons (C8-C16 ∼ 90%, C18-C28 ∼ 92%, C30 to C40 ∼ 88% loss) was observed in 60 d. Further, after 60 d of microcosm treatment, the treated soil samples were used for phytotoxicity assessment using wheat (Triticum aestivum), black chickpea (Cicer arietinum), and mustard (Brassica juncea). The germination rates for wheat (90%), black chickpea (100%), and mustard (100%) were observed in 7 d with improved shoot-root length and biomass in both bioaugmentation and biostimulation approaches. This study projects a comprehensive approach integrating bacterial consortium and nutrient augmentation strategies and underscores the vital role of innovative environmental management practices in fostering sustainable remediation of oil-contaminated soil ecosystems. The formulated bacterial consortium with a nutrient augmentation strategy can be utilized to restore agricultural lands towards reduced phytotoxicity and improved plant growth.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Solo/química , Ecossistema , Poluentes do Solo/análise , Hidrocarbonetos/metabolismo , Microbiologia do Solo
2.
Environ Res ; 225: 115592, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-36863654

RESUMO

"Save Soil Save Earth" is not just a catchphrase; it is a necessity to protect soil ecosystem from the unwanted and unregulated level of xenobiotic contamination. Numerous challenges such as type, lifespan, nature of pollutants and high cost of treatment has been associated with the treatment or remediation of contaminated soil, whether it be either on-site or off-site. Due to the food chain, the health of non-target soil species as well as human health were impacted by soil contaminants, both organic and inorganic. In this review, the use of microbial omics approaches and artificial intelligence or machine learning has been comprehensively explored with recent advancements in order to identify the sources, characterize, quantify, and mitigate soil pollutants from the environment for increased sustainability. This will generate novel insights into methods for soil remediation that will reduce the time and expense of soil treatment.


Assuntos
Metais Pesados , Poluentes do Solo , Humanos , Ecossistema , Inteligência Artificial , Poluição Ambiental/prevenção & controle , Metais Pesados/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Solo
3.
J Environ Manage ; 348: 119207, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37832293

RESUMO

The combustion of mobil oil leads to the emission of toxic compounds in the environment. In this study, the aromatic and aliphatic hydrocarbon fractions present in a waste mobil oil collected from automobile market were comprehensively identified and their toxicity was evaluated using wheat grain. Lysinibacillus sphaericus strain IITR51 isolated and characterized previously could degrade 30-80% of both aliphatic and aromatic hydrocarbons in liquid culture. Interestingly, the strain IITR51 produced 627 mg/L of rhamnolipid biosurfactant by utilizing 3% (v/v) of waste mobil oil in the presence of 1.5% glycerol as additional carbon source. In a soil microcosm study by employing strain IITR51, 50-86% of 3-6 ring aromatic hydrocarbons and 63-98% of aliphatic hydrocarbons (C8 to C22) were degraded. Addition of 60 µg/mL rhamnolipid biosurfactant enhanced the degradation of both aliphatic and aromatic hydrocarbons from 76.88% to 61.21%-94.11% and 78.27% respectively. The degradation of mobil oil components improved the soil physico-chemical properties and increased soil fertility to 64% as evident by the phytotoxicity assessments. The findings indicate that strain IITR51 with degradation capability coupled with biosurfactant production could be a candidate for restoring hydrocarbon contaminated soils.


Assuntos
Hidrocarbonetos Aromáticos , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Tensoativos/metabolismo , Solo/química , Poluentes do Solo/química , Hidrocarbonetos/metabolismo , Microbiologia do Solo
4.
J Food Sci Technol ; 60(3): 975-986, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36908343

RESUMO

In this study, a five-factorial central composite design was employed to optimize pectin extraction from novel source, through ultrasound-assisted extraction. A 35.58% yield was obtained under optimized conditions of pH 1.0, solid (g): liquid (mL) ratio 1:24, amplitude 84.2 Hz, duty cycle 23 s/30 s, and time 30 min. The equivalent weight, methoxyl content, anhydrouronic acid content, degree of esterification, water-holding capacity, and oil-holding capacity of the extracted pectin were 796.40 ± 2.07, 8.29 ± 0.38%, 71.32 ± 0.54%, 64.66 ± 2.08%, 8.04 ± 0.10 g water/g pectin, and 2.24 ± 030 g oil/g pectin, respectively. The chemical profile of the extracted pectin was assessed with FTIR and NMR analyses. The extracted pectin was utilized as a butter substitute in cookies. Up to 30% butter in cookies could be replaced with the extracted pectin without altering the sensory and physicochemical properties. Overall, results of presented work suggest that using waste-derived pectin as a fat substitute in cookies offers a sustainable and health-promoting approach for converting waste into wealth.

5.
Environ Res ; 209: 112793, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35090873

RESUMO

Global rise in the generation of waste has caused an enormous environmental concern and waste management problem. The untreated carbon rich waste serves as a breeding ground for pathogens and thus strategies for production of carbon rich biochar from waste by employing different thermochemical routes namely hydrothermal carbonization, hydrothermal liquefaction and pyrolysis has been of interest by researchers globally. Biochar has been globally produced due to its diverse applications from environmental bioremediation to energy storage. Also, several factors affect the production of biochar including feedstock/biomass type, moisture content, heating rate, and temperature. Recently the application of biochar has increased tremendously owing to the cost effectiveness and eco-friendly nature. Thus this communication summarized and highlights the preferred feedstock for optimized biochar yield along with the factor influencing the production. This review provides a close view on biochar activation approaches and synthesis techniques. The application of biochar in environmental remediation, composting, as a catalyst, and in energy storage has been reviewed. These informative findings were supported with an overview of lifecycle and techno-economical assessments in the production of these carbon based catalysts. Integrated closed loop approaches towards biochar generation with lesser/zero landfill waste for safeguarding the environment has also been discussed. Lastly the research gaps were identified and the future perspectives have been elucidated.


Assuntos
Carbono , Recuperação e Remediação Ambiental , Animais , Biodegradação Ambiental , Estágios do Ciclo de Vida , Pirólise
6.
Environ Res ; 215(Pt 2): 114198, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36063912

RESUMO

In this "plastic era" with the increased use of plastic in day today's life the accumulation of its degraded products like microplastics or plastic additives such as Bisphenol A(BPA) is also increasing. BPA is an endocrine-disrupting chemical used as a plasticizing agent in clear plastic, building materials, coatings, and epoxy resin. Several enzymes including laccases and lipases have been studied for the reduction of BPA toxicity. Over the decades of encountering these toxicants, microorganisms have evolved to degrade different classes of plastic additives. Since the degradation of BPA is a long process thus meta-omics approaches have been employed to identify the active microbiota and microbial dynamics involved in the mitigation of BPA. It is also necessary to investigate the impact of processing activities on transit of BPA in food items and to limit its entrance in food world. This review summarizes a comprehensive overview on BPA sources, toxicity, bio-based mitigation approaches along with a deeper understanding of multi-omics approaches for its reduction and risk analysis. Knowledge gaps and opportunities have been comprehensively compiled that would aid the state-of-the-art information in the available literature for the researchers to further address this issue.


Assuntos
Disruptores Endócrinos , Plásticos , Compostos Benzidrílicos/análise , Disruptores Endócrinos/análise , Disruptores Endócrinos/toxicidade , Resinas Epóxi , Microplásticos , Fenóis , Medição de Risco
7.
J Prosthet Dent ; 128(1): 101-106, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33551135

RESUMO

This clinical report presents the rehabilitation of extensive hard and soft tissue defects caused by rhino-orbital-cerebral mucormycosis as a result of untreated diabetes mellitus. The patient underwent subtotal maxillectomy and was rehabilitated with an implant-supported maxillofacial prosthesis with zygomatic and pterygoid implants by following an immediate loading protocol.


Assuntos
Implantes Dentários , Prótese Maxilofacial , Mucormicose , Prótese Dentária Fixada por Implante , Humanos , Maxila/cirurgia , Mucormicose/complicações , Mucormicose/cirurgia
8.
Microb Cell Fact ; 20(1): 163, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419059

RESUMO

Microalgae has the capability to replace petroleum-based fuels and is a promising option as an energy feedstock because of its fast growth, high photosynthetic capacity and remarkable ability to store energy reserve molecules in the form of lipids and starch. But the commercialization of microalgae based product is difficult due to its high processing cost and low productivity. Higher accumulation of these molecules may help to cut the processing cost. There are several reports on the use of various omics techniques to improve the strains of microalgae for increasing the productivity of desired products. To effectively use these techniques, it is important that the glycobiology of microalgae is associated to omics approaches to essentially give rise to the field of algal glycobiotechnology. In the past few decades, lot of work has been done to improve the strain of various microalgae such as Chlorella, Chlamydomonas reinhardtii, Botryococcus braunii etc., through genome sequencing and metabolic engineering with major focus on significantly increasing the productivity of biofuels, biopolymers, pigments and other products. The advancements in algae glycobiotechnology have highly significant role to play in innovation and new developments for the production algae-derived products as above. It would be highly desirable to understand the basic biology of the products derived using -omics technology together with biochemistry and biotechnology. This review discusses the potential of different omic techniques (genomics, transcriptomics, proteomics, metabolomics) to improve the yield of desired products through algal strain manipulation.


Assuntos
Biotecnologia/métodos , Genômica , Metabolômica , Microalgas/genética , Microalgas/metabolismo , Proteômica , Biocombustíveis , Engenharia Metabólica , Microalgas/classificação , Transcriptoma
9.
Phys Chem Chem Phys ; 17(27): 18111-20, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-26099851

RESUMO

Direct and indirect oxidation of guanine in DNA produces guanidinohydantoin (Gh), which is capable of inhibiting replication and inducing mutations during cellular activities. Although some biochemical studies have proposed that Gh may induce exclusively G to C mutations in DNA, other studies have predicted the occurrence of both G to C and G to T mutations. However, the exact reasons for these mutations and the dubious character of Gh in this context are not yet understood. Further, due to insufficient structural data, the electronic structure of Gh that can participate in the formation of different base pair complexes in DNA is also not known. Here, density functional theory (DFT) is used to find the most stable tautomers of Gh at the base level out of a total 112 possible tautomers and their involvement in mutagenesis is investigated by computing structures, energies and electronic properties of different base pair complexes formed between the syn- and anti-conformations of the most stable tautomer of Gh (aGh) and all the bases of DNA. It is found that aGh can coexist in R- and S-diastereoisomeric configurations. Due to the flexible guanidinium group, it can rotate about the N3-C4 bond in each of the above diastereoisomers to form two different stable conformations (aGh1 and aGh2). It is further shown that among the different base pair complexes involving aGh1, syn-aGh1:G is the most stable. This indicates that G would be easily incorporated against syn-aGh1 giving rise to G to C mutations in DNA. However, in the case of aGh2, G is the preferred base pair partner of syn-aGh2 and T is the preferred base pair partner of anti-aGh2. This implies that in addition to G to C mutations, the occurrence of aGh2 in DNA may also induce G to A mutations. Further, due to similarities between base pairing patterns and binding energies of syn-aGh1:A and syn-aGh2:A complexes with those of the T:A complex, DNA polymerases may mistakenly insert A opposite aGh1 or aGh2 by misrecognizing the latter as T. This may ultimately induce G to T mutations in DNA. However, as the constraints imposed by the DNA backbones and stacking interactions were not considered here, the possibilities of aGh2:T and aGh2:A base pairs need to be investigated experimentally. It is further found that the mutagenic character of aGh in the R- and S-diastereoisomeric forms is similar.


Assuntos
DNA/química , Guanidinas/química , Hidantoínas/química , Pareamento de Bases , DNA/metabolismo , Guanina/química , Ligação de Hidrogênio , Mutagênese , Conformação de Ácido Nucleico , Oxirredução , Estereoisomerismo
10.
Iran J Microbiol ; 16(1): 132-138, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38682056

RESUMO

Background and Objectives: In India, it is estimated that there are 40 million people suffering from Hepatitis B virus (HBV). Quantification of the viral burden is an important laboratory tool in the management. However, widespread use of different HBV-DNA assays is still affected by the high cost and variable diagnostic precision. The present study was conducted to evaluate the diagnostic precision and co-relation of ALT levels with HBV-DNA by Truenat®-PCR. Materials and Methods: In this prospective cross-sectional study a total of 567 serums were collected from patients by rapid HBsAg, and processed for liver function tests (LFT). The viral HBV-DNA amplification detection was carried out through by Truenat®-PCR test. Results: Out of 567 samples, 452 samples were found to be positive by both rapid and Truenat®-PCR and 106 were negative for HBV-DNA followed by 9 invalid. High ALT level found in 73% of positive patients who had HBV-DNA level (>100000 copies/ml) which is significantly higher in 447 patients as compared to those have below ≤100000 copies/ml. Conclusion: Truenat®-PCR technique is a highly sensitive and can be performed with low resources for effective control of HBV infection. Evaluation of HBV-DNA levels and serum ALT levels showed a significant proportion of patient harbored ongoing viral replication and disease progression.

11.
Bioresour Technol ; 397: 130469, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382722

RESUMO

This study focuses on the development of a scalable method for producing poly(3-hydroxypropionate), a homopolymer with significant physico-mechanical properties, through the use of metabolically-engineered Escherichia coli K12 (MG1655) and externally supplied 3-hydroxypropionate. The polymer synthesis pathway was established and optimized through synthetic biology techniques, including the effects of overexpressing phasin and cell division proteins. The optimized strain achieved unprecedented production titers of 9.5 g/L in flask cultures and 80 g/L in fed-batch bioreactors within 45 h. The analysis of poly(3-hydroxypropionate) polymer properties revealed it possesses excellent elasticity (Young's modulus < 6 MPa) and tensile strength (∼80 MPa), positioning it within the category of elastomers or flexible plastics. These findings suggest a viable path for the sustainable, large-scale production of the poly(3-hydroxypropionate) biopolymer.


Assuntos
Escherichia coli , Ácido Láctico/análogos & derivados , Engenharia Metabólica , Escherichia coli/metabolismo , Poliésteres/metabolismo
12.
Environ Pollut ; 354: 124134, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38734050

RESUMO

This review article explores the challenges associated with landfill leachate resulting from the increasing disposal of municipal solid waste in landfills and open areas. The composition of landfill leachate includes antibiotics (0.001-100 µg), heavy metals (0.001-1.4 g/L), dissolved organic and inorganic components, and xenobiotics including polyaromatic hydrocarbons (10-25 µg/L). Conventional treatment methods, such as biological (microbial and phytoremediation) and physicochemical (electrochemical and membrane-based) techniques, are available but face limitations in terms of cost, accuracy, and environmental risks. To surmount these challenges, this study advocates for the integration of artificial intelligence (AI) and machine learning (ML) to strengthen treatment efficacy through predictive analytics and optimized operational parameters. It critically evaluates the risks posed by recalcitrant leachate components and appraises the performance of various treatment modalities, both independently and in tandem with biological and physicochemical processes. Notably, physicochemical treatments have demonstrated pollutant removal rates of up to 90% for various contaminants, while integrated biological approaches have achieved over 95% removal efficiency. However, the heterogeneous nature of solid waste composition further complicates treatment methodologies. Consequently, the integration of advanced ML algorithms such as Support Vector Regression, Artificial Neural Networks, and Genetic Algorithms is proposed to refine leachate treatment processes. This review provides valuable insights for different stakeholders specifically researchers, policymakers and practitioners, seeking to fortify waste disposal infrastructure and foster sustainable landfill leachate management practices. By leveraging AI and ML tools in conjunction with a nuanced understanding of leachate complexities, a promising pathway emerges towards effectively addressing this environmental challenge while mitigating potential adverse impacts.


Assuntos
Aprendizado de Máquina , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Eliminação de Resíduos/métodos , Biodegradação Ambiental , Resíduos Sólidos , Metais Pesados/análise , Inteligência Artificial
13.
Bioresour Technol ; 389: 129814, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37783239

RESUMO

1,3-Butanediol (1,3-BDO) finds versatile applications in the cosmetic, chemical, and food industries. This study focuses on the metabolic engineering of Escherichia coli K12 to achieve efficient production of 1,3-BDO from glucose via acetoacetyl-CoA, 3-hydroxybutyryl-CoA, and 3-hydroxybutyraldehyde. The accumulation of an intermediary metabolite (pyruvate) and a byproduct (3-hydroxybutyric acid) was reduced by disruption of the negative transcription factor (PdhR) for pyruvate dehydrogenase complex (PDHc) and employing an efficient alcohol dehydrogenase (YjgB), respectively. Additionally, to improve NADPH availability, carbon flux was redirected from the Embden-Meyerhof-Parnas (EMP) pathway to the Entner-Doudoroff (ED) pathway. One resulting strain achieved a record-high titer of 790 mM (∼71.1 g/L) with a yield of 0.65 mol/mol for optically pure (R)-1,3-BDO, with an enantiomeric excess (e.e.) value of 98.5 %. These findings are useful in the commercial production of 1,3-BDO and provide valuable insights into the development of an efficient cell factory for other acetyl-CoA derivatives.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Engenharia Metabólica , Glucose/metabolismo , Glicólise , Butileno Glicóis/metabolismo , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Proteínas de Escherichia coli/genética
14.
J Hazard Mater ; 441: 129906, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088882

RESUMO

For decades, reclamation of pesticide contaminated sites has been a challenging avenue. Due to increasing agricultural demand, the application of synthetic pesticides could not be controlled in its usage, and it has now adversely impacted the soil, water, and associated ecosystems posing adverse effects on human health. Agricultural soil and pesticide manufacturing sites, in particular, are one of the most contaminated due to direct exposure. Among various strategies for soil reclamation, ecofriendly microbial bioremediation suffers inherent challenges for large scale field application as interaction of microbes with the polluted soil varies greatly under climatic conditions. Methodically, starting from functional or genomic screening, enrichment isolation; functional pathway mapping, production of tensioactive metabolites for increasing the bioavailability and bio-accessibility, employing genetic engineering strategies for modifications in existing catabolic genes to enhance the degradation activity; each step-in degradation study has challenges and prospects which can be addressed for successful application. The present review critically examines the methodical challenges addressing the feasibility for restoring and reclaiming pesticide contaminated sites along with the ecotoxicological risk assessments. Overall, it highlights the need to fine-tune the available processes and employ interdisciplinary approaches to make microbe assisted bioremediation as the method of choice for reclamation of pesticide contaminated sites.


Assuntos
Praguicidas , Poluentes do Solo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Ecossistema , Estudos de Viabilidade , Humanos , Praguicidas/metabolismo , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Água
15.
Environ Sci Pollut Res Int ; 30(18): 51770-51781, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36820967

RESUMO

Indole is a nitrogenous heterocyclic aromatic pollutant often detected in various environments. An efficient indole degrading bacterium strain IITR89 was isolated from River Cauvery, India, and identified as Alcaligenes faecalis subsp. phenolicus. The bacterium was found to degrade ~ 95% of 2.5 mM (293.75 mg/L) of indole within 18 h utilizing it as a sole carbon and energy source. Based on metabolite identification, the metabolic route of indole degradation is indole → (indoxyl) → isatin → (anthranilate) → salicylic acid → (catechol) → (Acetyl-CoA) → and further entering into TCA cycle. Genome sequencing of IITR89 revealed the presence of gene cluster dmpKLMNOP, encoding multicomponent phenol hydroxylase; andAbcd gene cluster, encoding anthranilate 1,2-dioxygenase ferredoxin subunit (andAb), anthranilate 1,2-dioxygenase large subunit (andAc), and anthranilate 1,2-dioxygenase small subunit (andAd); nahG, salicylate hydroxylase; catA, catechol 1,2-dioxygenase; catB, cis, cis-muconate cycloisomerase; and catC, muconolactone D-isomerase which play an active role in indole degradation. The findings strongly support the degradation potential of strain IITR89 and its possible application for indole biodegradation.


Assuntos
Alcaligenes faecalis , Alcaligenes faecalis/genética , Alcaligenes faecalis/metabolismo , Proteínas de Bactérias/genética , Biodegradação Ambiental , Genômica , Indóis/metabolismo
16.
Chemosphere ; 337: 139264, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37348617

RESUMO

Pollution from the oil industries and refineries has worsened various environmental compartments. In this study, indigenous oil degrading bacteria were isolated from crude oil obtained from an Oil and Natural Gas Corporation (ONGC) asset in Ankleshwar, Gujarat, India. Based on 16S rRNA phylogeny, they were identified as Pseudomonas boreopolis IITR108, Microbacterium schleiferi IITR109, Pseudomonas aeruginosa IITR110, and Bacillus velezensis IITR111. The strain IITR108, IITR109, IITR110, and IITR111 showed 80-89% and 71-78% degradation of aliphatic (C8-C40) and aromatic (4-5 ring) hydrocarbons respectively in 45 d when supplemented with 3% (v/v) waste crude oil. When compared to individual bacteria, the consortium degrades 93.2% of aliphatic hydrocarbons and 85.5% of polyaromatic hydrocarbons. It was observed that the total aliphatic and aromatic content of crude oil 394,470 µg/mL and 47,050 µg/mL was reduced up to 9617.75 µg/mL and 4586 µg/mL respectively in 45 d when consortium was employed. The rate kinetics analysis revealed that the biodegradation isotherm followed first order kinetics, with a linear correlation between concentration (hydrocarbons) and time intervals. The half-life of aliphatic (C8-C40) and aromatic hydrocarbons ranged from 200 to 453 h and 459-714 h respectively. All the bacteria efficiently produced catabolic enzymes such as alkane monooxygenase, alcohol dehydrogenase, and lipase during the degradation of crude oil. These findings indicated that the bacterial consortium can be a better candidate for bioremediation and reclamation of aliphatic and aromatics hydrocarbon contaminated sites.


Assuntos
Hidrocarbonetos Aromáticos , Petróleo , Poluentes do Solo , Petróleo/análise , Cinética , Meia-Vida , Solo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Poluentes do Solo/análise
17.
Bioresour Technol ; 376: 128911, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36934906

RESUMO

The production of 1,3-butanediol (1,3-BDO) from glucose was investigated using Escherichia coli as the host organism. A pathway was engineered by overexpressing genes phaA (acetyl-CoA acetyltransferase), phaB (acetoacetyl-CoA reductase), bld (CoA-acylating aldehyde dehydrogenase), and yqhD (alcohol dehydrogenase). The expression levels of these genes were optimized to improve 1,3-BDO production and pathways that compete with 1,3-BDO synthesis were disrupted. Culture conditions were also optimized, including the C: N ratio, aeration, induction time, temperature, and supplementation of amino acids, resulting in a strain that could produce 1,3-BDO at 257 mM in 36 h, with a yield of 0.51 mol/mol in a fed-batch bioreactor experiment. To the best of our knowledge, this is the highest titer of 1,3-BDO production ever reported using biological methods, and our findings provide a promising strategy for the development of microbial cell factories for the sustainable synthesis of other acetyl-CoA-derived chemicals.


Assuntos
Escherichia coli , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Engenharia Metabólica/métodos , Álcool Desidrogenase/metabolismo , Reatores Biológicos , Butileno Glicóis/metabolismo
18.
Chemosphere ; 311(Pt 1): 136877, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36257395

RESUMO

The recent upsurge in the studies on micro/nano plastics and antimicrobial resistance genes has proven their deleterious effects on the environmental and human health. Till-date, there is a scarcity of studies on the interactions of these two factors and their combined influence. The interaction of microplastics has led to the formation of new plastics namely plastiglomerates, pyroplastics. and anthropoquinas. It has long been ignored that the occurrence of microplastics has become a breeding ground for the emergence of antimicrobial resistance genes. Evidently microplastics are also associated with the occurrence of other pollutants such as polyaromatic hydrocarbons and pesticides. The increased use of antibiotics (after Covid breakout) has further elevated the detrimental effects on human health. Therefore, this study highlights the relation of microplastics with antibiotic resistance generation. The factors such as uncontrolled use of antibiotics and negligent plastic consumption has been evaluated. Furthermore, the future research prospective was provided that can be helpful in correctly identifying the seriousness of the environmental occurrence of these pollutants.


Assuntos
COVID-19 , Poluentes Ambientais , Poluentes Químicos da Água , Humanos , Microplásticos , Antibacterianos/farmacologia , Plásticos , Estudos Prospectivos , Farmacorresistência Bacteriana/genética , Poluição Ambiental , Poluentes Ambientais/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Monitoramento Ambiental
19.
Bioresour Technol ; 373: 128750, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36796731

RESUMO

Free cyanide is a hazardous pollutant released from steel industries. Environmentally-safe remediation of cyanide-contaminated wastewater is required. In this work, Pseudomonas stutzeri (ASNBRI_B12), Trichoderma longibrachiatum (ASNBRI_F9), Trichoderma saturnisporum (ASNBRI_F10) and Trichoderma citrinoviride (ASNBRI_F14) were isolated from blast-furnace wastewater and activated-sludge by enrichment culture. Elevated microbial growth, rhodanese activity (82 %) and GSSG (128 %) were observed with 20 mg-CN L-1. Cyanide degradation > 99 % on 3rd d as evaluated through ion chromatography, followed by first-order kinetics (r2 = 0.94-0.99). Cyanide degradation in wastewater (20 mg-CN L-1, pH 6.5) was studied in ASNBRI_F10 and ASNBRI_F14 which displayed increased biomass to 49.7 % and 21.6 % respectively. Maximum cyanide degradation of 99.9 % in 48 h was shown by an immobilized consortium of ASNBRI_F10 and ASNBRI_F14. FTIR analysis revealed that cyanide treatment alters functional groups on microbial cell walls. The novel consortium of T. saturnisporum-T. citrinoviride in the form of immobilized culture can be employed to treat cyanide-contaminated wastewater.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Cianetos/metabolismo , Águas Residuárias , Esgotos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental
20.
Bioresour Technol ; 387: 129581, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37517709

RESUMO

Lindane, an organochlorine pesticide, negatively affects living beings and the ecosystem. In this study, the potential of 9 Ascomycetes fungi, isolated from an hexachlorocyclohexane dumpsite soil, was tested for biodegradation of lindane. The strain Pleurostoma richardsiae (FN5) showed lindane biodegradation rate constant (K value) of 0.144 d-1 and a half-life of 4.8d. The formation of intermediate metabolites upon lindane degradation including γ-pentachlorocyclohexene, 2,4-dichlorophenol, phenol, benzene, 1,3- cyclohexadiene, and benzoic acid detected by GC-MS and the potential pathway adopted by the novel fungal strain FN5 for lindane biodegradation has been elucidated. The study of gene profiles with reference to linA and linB in strain FN5 confirmed the same protein family with the reported heterologs from other fungal strains in the NCBI database. This study for the first time provides a thorough understanding of lindane biodegradation by a novel soil-borne Ascomycota fungal strain for its possible application in field-scale bioremediation.


Assuntos
Ascomicetos , Hexaclorocicloexano , Hexaclorocicloexano/metabolismo , Biodegradação Ambiental , Solo , Ecossistema , Cinética , Ascomicetos/metabolismo , Microbiologia do Solo
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