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1.
Chemosphere ; 286(Pt 1): 131552, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34320440

RESUMO

Bioaugmented biotrickling filter (BTF) seeded with Piscinibacter caeni MQ-18, Pseudomonas oleovorans DT4, and activated sludge was established to investigate the treatment performance and biodegradation kinetics of the gaseous mixtures of tetrahydrofuran (THF) and methyl tert-butyl ether (MTBE). Experimental results showed an enhanced startup performance with a startup period of 9 d in bioaugmented BTF (25 d in control BTF seeded with activated sludge). The interaction parameter I2,1 of control (7.462) and bioaugmented BTF (3.267) obtained by the elimination capacity-sum kinetics with interaction parameter (EC-SKIP) model indicated that THF has a stronger inhibition of MTBE biodegradation in the control BTF than in the bioaugmented BTF. Similarly, the self-inhibition EC-SKIP model quantified the positive effects of MTBE on THF biodegradation, as well as the negative effects of THF on MTBE biodegradation and the self-inhibition of MTBE and THF. Metabolic intermediate analysis, real-time quantitative polymerase chain reaction, biofilm-biomass determination, and high-throughput sequencing revealed the possible mechanism of the enhanced treatment performance and biodegradation interactions of MTBE and THF.


Assuntos
Éteres Metílicos , Pseudomonas oleovorans , Biodegradação Ambiental , Burkholderiales , Furanos , Éteres Metílicos/análise
2.
Braz J Biol ; 83: e240015, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34320047

RESUMO

Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.


Assuntos
Pseudomonas oleovorans , Poluentes do Solo , Humanos , RNA Ribossômico 16S/genética , Solo , Microbiologia do Solo , Zinco
3.
Bioresour Technol ; 338: 125568, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34274579

RESUMO

Bioaugmentation in wastewater treatment plants (WWTPs) is challenging due to low survival and persistence of applied microbes. This study aimed to track the capacity and survival of fluorescent-tagged Pseudomonas oleovoransICTN13 as a model organism applicable in bioaugmentation of phenol-containing wastewater. The isolate was immobilized in alginate biopolymer, and enhanced efficacy and survival for biodegradation of phenol against free cells were studied. Encapsulated cells resulted in enhanced phenol removal efficiency (~94%) compared to free cells (~72%). Encapsulation of cells facilitated an extended storage time of 30 days. Remarkably, phenol and COD removal efficacy of encapsulated cells was sustained up to ~ 92-93% in a reactor after 45 days, while free cells could produce ~ 80-84% removal efficiency. Fluorescence microscopy showed high survival of the encapsulated cells, whereas gradual deterioration of free cells was observed. Thus, the findings highlight the importance of bio augmented strain in WWTPs where encapsulation is a crucial factor.


Assuntos
Fenol , Pseudomonas oleovorans , Biodegradação Ambiental , Células Imobilizadas , Fenóis , Águas Residuárias
4.
Arch Microbiol ; 203(6): 3117-3124, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33797591

RESUMO

A bacterial strain ODT-83 is isolated from oysters, which is capable of adsorbing norovirus (NoV) via histo-blood group antigen-like (HBGA-like) substances. To better understand its genetic background associated with the production of HBGA-like substances, the genome of the ODT-83 was completely sequenced and analyzed. The ODT-83 only contains one circular chromosome, with a length of 5,384,159 bp. Both the 16S rRNA gene phylogeny and the average nucleotide identity (ANI) analyses confirm that the ODT-83 is a new Pseudomonas oleovorans strain. The whole genome encodes a total of 5037 predicted open reading frames (ORFs), 66 tRNA genes and 12 rRNA genes. Two gene clusters are detected on the genome, which are involved in the synthesis of polysaccharides of alginate and Pel, respectively. These results lay the foundation for further research on the interaction between the P. oleovorans strain ODT-83 and NoV.


Assuntos
Genoma Bacteriano , Ostreidae , Pseudomonas oleovorans , Animais , Técnicas de Tipagem Bacteriana , Ácidos Graxos/análise , Genoma Bacteriano/genética , Ostreidae/microbiologia , Filogenia , Pseudomonas/genética , Pseudomonas oleovorans/classificação , Pseudomonas oleovorans/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
5.
Arch Toxicol ; 94(10): 3487-3502, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32681188

RESUMO

The skin`s microbiome is predominantly commensalic, harbouring a metabolic potential far exceeding that of its host. While there is clear evidence that bacteria-dependent metabolism of pollutants modulates the toxicity for the host there is still a lack of models for investigating causality of microbiome-associated pathophysiology or toxicity. We now report on a biologically characterised microbial-skin tissue co-culture that allows studying microbe-host interactions for extended periods of time in situ. The system is based on a commercially available 3D skin model. In a proof-of-concept, this model was colonised with single and mixed cultures of two selected skin commensals. Two different methods were used to quantify the bacteria on the surface of the skin models. While Micrococcus luteus established a stable microbial-skin tissue co-culture, Pseudomonas oleovorans maintained slow continuous growth over the 8-day cultivation period. A detailed skin transcriptome analysis showed bacterial colonisation leading to up to 3318 significant changes. Additionally, FACS, ELISA and Western blot analyses were carried out to analyse secretion of cytokines and growth factors. Changes found in colonised skin varied depending on the bacterial species used and comprised immunomodulatory functions, such as secretion of IL-1α/ß, Il-6, antimicrobial peptides and increased gene transcription of IL-10 and TLR2. The colonisation also influenced the secretion of growth factors such as VFGFA and FGF2. Notably, many of these changes have already previously been associated with the presence of skin commensals. Concomitantly, the model gained first insights on the microbiome's influence on skin xenobiotic metabolism (i.e., CYP1A1, CYP1B1 and CYP2D6) and olfactory receptor expression. The system provides urgently needed experimental access for assessing the toxicological impact of microbiome-associated xenobiotic metabolism in situ.


Assuntos
Interações entre Hospedeiro e Microrganismos , Micrococcus luteus/crescimento & desenvolvimento , Pseudomonas oleovorans/crescimento & desenvolvimento , Pele/microbiologia , Anti-Infecciosos/metabolismo , Citocinas/metabolismo , Perfilação da Expressão Gênica , Humanos , Imunomodulação , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Modelos Biológicos , Pele/metabolismo , Simbiose , Técnicas de Cultura de Tecidos
6.
Chemosphere ; 258: 127148, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535434

RESUMO

Tetrahydrofuran (THF) is a common highly toxic cyclic aliphatic ether that frequently exists in waste gases. Removal of gaseous THF is a serious issue with important environmental ramifications. A novel three-phase airlift bioreactor (TPAB) loaded with immobilized cells was developed for efficient THF removal from gas streams. An effective THF-degrading transformant, Pseudomonas oleovorans GDT4, which contains the pTn-Mod-OTc-gfp plasmid and was tagged with a green fluorescent protein (GFP), was constructed. Continuous treatment of THF-containing waste gases was succeeded by the GFP-labelled cells immobilized with calcium alginate and activated carbon fiber in the TPAB for 60 days with >90% removal efficiency. The number of fluorescent cells in the beads reached 1.7 × 1011 cells·g-1 of bead on day 10, accounting for 83.3% of the total number of cells. The amount further increased to 3.0 × 1011 cells·g-1 of bead on day 40. However, it decreased to 2.5 × 1011 cells·g-1 of bead with a substantial increase in biomass in the liquid because of cell leakage and hydraulic shock. PCR-DGGE revealed that P. oleovorans was the dominant microorganism throughout the entire operation. The maximum elimination capacity was affected by empty bed residence time (EBRT). The capacity was only 25.9 g m-3·h-1 at EBRT of 80 s, whereas it reached 37.8 g m-3·h-1 at EBRT of 140 s. This work provides an alternative method for full-scale removal of gaseous THF and presents a useful tool for determining the biomass of a specific degrader in immobilized beads.


Assuntos
Reatores Biológicos/microbiologia , Furanos/metabolismo , Pseudomonas oleovorans/metabolismo , Gerenciamento de Resíduos/métodos , Alginatos/química , Biodegradação Ambiental , Biomassa , Fibra de Carbono , Células Imobilizadas/metabolismo , Carvão Vegetal , Desenho de Equipamento , Gases , Proteínas de Fluorescência Verde/genética , Microbiota , Microrganismos Geneticamente Modificados , Pseudomonas oleovorans/citologia , Pseudomonas oleovorans/genética , Gerenciamento de Resíduos/instrumentação
7.
Occup Med (Lond) ; 69(8-9): 632-634, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31504833

RESUMO

Hypersensitivity pneumonitis (HP) is a chronic inflammatory lung disease caused by repeated inhalation of antigenic substances. We present a case of metalworking fluids (MWFs)-HP sensitized to Pseudomonas oleovorans in a cystic fibrosis patient. This case illustrates that HP diagnosis remains challenging, especially in patients with another pulmonary disease, and that serodiagnosis contributes to identifying the precise microorganism involved. It also demonstrates that P. oleovorans is an important secondary aetiological agent in MWF-HP, less known than Mycobacterium immunogenum.


Assuntos
Alveolite Alérgica Extrínseca/diagnóstico , Fibrose Cística/complicações , Doenças Profissionais/diagnóstico , Adulto , Alveolite Alérgica Extrínseca/tratamento farmacológico , Alveolite Alérgica Extrínseca/etiologia , Alveolite Alérgica Extrínseca/microbiologia , Antígenos de Bactérias , França , Humanos , Óleos Industriais/microbiologia , Masculino , Metalurgia , Doenças Profissionais/imunologia , Doenças Profissionais/microbiologia , Exposição Ocupacional , Pseudomonas oleovorans/imunologia
8.
Appl Environ Microbiol ; 85(2)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30413473

RESUMO

Amination of bulky ketones, particularly in (R) configuration, is an attractive chemical conversion; however, known ω-transaminases (ω-TAs) show insufficient levels of performance. By applying two screening methods, we discovered 10 amine transaminases from the class III ω-TA family that were 38% to 76% identical to homologues. We present examples of such enzymes preferring bulky ketones over keto acids and aldehydes with stringent (S) selectivity. We also report representatives from the class III ω-TAs capable of converting (R) and (S) amines and bulky ketones and one that can convert amines with longer alkyl substituents. The preference for bulky ketones was associated with the presence of a hairpin region proximal to the conserved Arg414 and residues conforming and close to it. The outward orientation of Arg414 additionally favored the conversion of (R) amines. This configuration was also found to favor the utilization of putrescine as an amine donor, so that class III ω-TAs with Arg414 in outward orientation may participate in vivo in the catabolism of putrescine. The positioning of the conserved Ser231 also contributes to the preference for amines with longer alkyl substituents. Optimal temperatures for activity ranged from 45 to 65°C, and a few enzymes retained ≥50% of their activity in water-soluble solvents (up to 50% [vol/vol]). Hence, our results will pave the way to design, in the future, new class III ω-TAs converting bulky ketones and (R) amines for the production of high-value products and to screen for those converting putrescine.IMPORTANCE Amine transaminases of the class III ω-TAs are key enzymes for modification of chemical building blocks, but finding those capable of converting bulky ketones and (R) amines is still challenging. Here, by an extensive analysis of the substrate spectra of 10 class III ω-TAs, we identified a number of residues playing a role in determining the access and positioning of bulky ketones, bulky amines, and (R)- and (S) amines, as well as of environmentally relevant polyamines, particularly putrescine. The results presented can significantly expand future opportunities for designing (R)-specific class III ω-TAs to convert valuable bulky ketones and amines, as well as for deepening the knowledge into the polyamine catabolic pathways.


Assuntos
Proteínas de Bactérias/genética , Bioprospecção , Genes Bacterianos , Cetonas/metabolismo , Poliaminas/metabolismo , Pseudomonas oleovorans/genética , Transaminases/genética , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Pseudomonas oleovorans/enzimologia , Pseudomonas oleovorans/metabolismo , Alinhamento de Sequência , Transaminases/metabolismo
9.
Int J Biol Macromol ; 107(Pt A): 276-282, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28867233

RESUMO

A sticky polymer, poly(3-hydroxyundecenoate) (PHU), was produced by Pseudomonas oleovorans when nonanoate and undecenoate were used as carbon sources. Crosslinked PHU (CL-PHU) was prepared by heating using benzoyl peroxide as a crosslinker. According to the degree of crosslinking in the polymer, three types of CL-PHU were prepared: CL-PHU50, CL-PHU60 and CL-PHU70. Fourier transform-infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry results suggested that crosslinking of PHU was successfully achieved by heat, which increased the crosslinking density and decreased stiffness and flexibility of the polymer. Water contact angle measurements revealed no differences of hydrophilicity as the crosslinking density. Slight morphological changes of CL-PHU film surfaces were observed by atomic force microscopy. Chinese hamster ovary cells were used to investigate the biocompatibility of CL-PHU films using poly(l-lactide) surfaces as control. Surface properties of the film, such as roughness and adhesive force, enhanced the adhesion and proliferation of cells on the films. CL-PHU might be useful for cell compatible biomedical applications.


Assuntos
Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Polímeros/química , Ácidos Undecilênicos/química , Animais , Peróxido de Benzoíla/química , Materiais Biocompatíveis/farmacologia , Células CHO , Varredura Diferencial de Calorimetria , Cricetulus , Reagentes para Ligações Cruzadas/química , Microscopia de Força Atômica , Polímeros/farmacologia , Pseudomonas oleovorans/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Ácidos Undecilênicos/farmacologia
10.
J Asian Nat Prod Res ; 19(7): 712-718, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27666872

RESUMO

The pentacyclic triterpenoid hederagenin (1) was subjected to biotransformation by Cunninghamella echinulate CGMCC 3.2000, Mucor subtilissimus CGMCC 3.2454 and Pseudomonas oleovorans CGMCC 1.1641. Three metabolites were obtained. On the basis of nuclear magnetic resonance and high-resolution mass spectral analyses, their structures were characterized as 3ß, 23-dihydroxyolean-12-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (2), 3ß, 15α, 23-trihydroxyolean-12-en-28-oic acid (3), 1ß, 3ß, 23-trihydroxyolean-12-en-28-oic acid (4), and metabolite (3) was a new compound. This was the first report on the biotransformation of hederagenin.


Assuntos
Cunninghamella/metabolismo , Mucor/metabolismo , Ácido Oleanólico/análogos & derivados , Pseudomonas oleovorans/metabolismo , Biotransformação , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Ácido Oleanólico/química , Saponinas/química
11.
N Biotechnol ; 35: 35-41, 2017 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-27884748

RESUMO

Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP.


Assuntos
Achromobacter/metabolismo , Compostos de Bifenilo/metabolismo , Éteres Fenílicos/metabolismo , Pseudomonas/metabolismo , Achromobacter/isolamento & purificação , Biodegradação Ambiental , Biotecnologia , Temperatura Alta , Microbiologia Industrial , Pseudomonas/isolamento & purificação , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/metabolismo , Pseudomonas oleovorans/isolamento & purificação , Pseudomonas oleovorans/metabolismo , Rizosfera , Microbiologia do Solo , Energia Solar
12.
J Hazard Mater ; 320: 479-486, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27585280

RESUMO

Polyfluoroalkyl phosphates (PAPs), a group of fluorotelomer alcohol (FTOH)-based surfactants commonly used in water- and grease-proof food contact paper, have been suggested as a direct source of human exposure to health-concerned perfluoroalkyl carboxylic acids (PFCAs). This study investigated factors affecting biotranformation of 6:2 polyfluoroalkyl phosphates (6:2 PAPs) by three known FTOH-degrading Pseudomonas strains (Pseudomonas butanovora, P. oleovorans, and P. fluorescens DSM 8341) under different co-substrate conditions and compared to that by activated sludge samples. The three pure strains transformed 6:2 PAPs into eight different per- and poly-fluoroalkyl carboxylic acids (PFCAs) and/or PFCA precursors. P. fluorescens DSM 8341 produced 5:2 sFTOH [CF3(CF2)4CH(OH)CH3] and P. oleovorans produced 5:2 ketone [CF3(CF2)4C(O)CH3] as the primary transformation product, respectively, with citrate having a minimal impact on the transformation. P. butanovora with lactate produced more diverse transformation products than those by any two strains. Activated sludge was more efficient at transforming 6:2 PAPs and produced more transformation products including PFHpA [CF3(CF2)5COOH] and PFPeA [CF3(CF2)3COOH], with 5:2 sFTOH as the most abundant product on day 30. The abundance of the alkane hydroxylase (alkB) gene related to alkane oxidation, the changes of total microbial population as well as their community structure in activated sludge during 6:2 PAPs biotransformation were also investigated.


Assuntos
Hidrocarbonetos Fluorados/metabolismo , Fosfatos/metabolismo , Pseudomonas fluorescens/metabolismo , Pseudomonas oleovorans/metabolismo , Enzimas AlkB/genética , Biotransformação , Consórcios Microbianos , Pseudomonas fluorescens/isolamento & purificação , Pseudomonas oleovorans/isolamento & purificação , Esgotos/microbiologia
14.
Mar Genomics ; 20: 17-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25528517

RESUMO

Pseudomonas oleovorans MGY01 isolated from the deep-sea water of the South China Sea could effectively degrade malachite green. The draft genome of P. oleovorans MGY01 was sequenced and analyzed to gain insights into its efficient metabolic pathway for degrading malachite green. The data obtained revealed 109 Contigs (N50; 128,269 bp) with whole genome size of 5,201,892 bp. The draft genome sequence of strain MGY01 will be helpful in studying the genetic pathways involved in the degradation of malachite green.


Assuntos
Genoma Bacteriano , Pseudomonas oleovorans/genética , Água do Mar/microbiologia , Dados de Sequência Molecular , Microbiologia da Água
15.
Biotechnol Bioeng ; 111(10): 1920-30, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24771278

RESUMO

OPHC2 is a thermostable organophosphate (OP) hydrolase in the ß-lactamase superfamily. OPs are highly toxic synthetic chemicals with no natural analogs. How did OPHC2 acquire phosphotriesterase (PTE) activity remained unclear. In this study, an OPHC2 analogue, PoOPH was discovered from Pseudomonas oleovorans exhibiting high lactonase and esterase activities and latent PTE activity. Sequence analysis revealed conserved His250 and Ile263 and site-directed mutagenesis at these crucial residues enhanced PTE activity. The best variant PoOPHM2 carrying H250I/I263W mutations displayed 6,962- and 106-fold improvements in catalytic efficiency for methyl-parathion and ethyl-paraoxon degradation, whereas the original lactonase and esterase activities decreased dramatically. A 1.4 × 10(7) -fold of specificity inversion was achieved by only two residue substitutions. Significantly, thermostability of the variants was not compromised. Crystal structure of PoOPHM2 was determined at 2.25 Å resolution and docking studies suggested that the two residues in the binding pocket determine substrate recognition. Lastly, new organophosphorus hydrolases (OPHs) were discovered using simple double mutations. Among them, PpOPHM2 from Pseudomonas putida emerged as a new promising OPH with very high activity (41.0 U mg(-1) ) toward methyl-parathion. Our results offer a first scrutiny to PTE activity evolution of OPHs in ß-lactamase superfamily and provide efficient and robust enzymes for OP detoxification.


Assuntos
Arildialquilfosfatase/química , Hidrolases de Triester Fosfórico/química , Pseudomonas oleovorans/enzimologia , beta-Lactamases/química , Sequência de Aminoácidos , Arildialquilfosfatase/genética , Arildialquilfosfatase/metabolismo , Cristalografia por Raios X , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Hidrolases de Triester Fosfórico/genética , Hidrolases de Triester Fosfórico/metabolismo , Conformação Proteica , Estabilidade Proteica , Pseudomonas oleovorans/química , Pseudomonas oleovorans/genética , Alinhamento de Sequência , Especificidade por Substrato , beta-Lactamases/genética , beta-Lactamases/metabolismo
16.
Int J Environ Res Public Health ; 12(1): 371-84, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25561017

RESUMO

The biodegradation kinetics of tetrahydrofuran, benzene (B), toluene (T), and ethylbenzene (E) were systematically investigated individually and as mixtures by a series of aerobic batch degradation experiments initiated by Pseudomonas oleovorans DT4. The Andrews model parameters, e.g., maximum specific growth rates (µmax), half saturation, and substrate inhibition constant, were obtained from single-substrate experiments. The interaction parameters in the sum kinetics model (SKIP) were obtained from the dual substrates. The µmax value of 1.01 for tetrahydrofuran indicated that cell growth using tetrahydrofuran as carbon source was faster than the growth on B (µmax, B = 0.39) or T (µmax, T = 0.39). The interactions in the dual-substrate experiments, including genhancement, inhibition, and co-metabolism, in the mixtures of tetrahydrofuran with B or T or E were identified. The degradation of the four compounds existing simultaneously could be predicted by the combination of SKIP and co-metabolism models. This study is the first to quantify the interactions between tetrahydrofuran and BTE.


Assuntos
Derivados de Benzeno/metabolismo , Poluentes Ambientais/metabolismo , Furanos/metabolismo , Pseudomonas oleovorans/metabolismo , Solventes/metabolismo , Biodegradação Ambiental , Cinética , Especificidade por Substrato
17.
Huan Jing Ke Xue ; 34(8): 3251-6, 2013 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-24191576

RESUMO

A new composite matrix, calcium alginate (CA) coupled with activated carbon fiber (ACF) was designed to immobilize the cells of Pseudomonas oleovorans DT4 for tetrahydrofuran (THF) degradation. The average removal rate of the CA-ACF immobilized cells reached 24.0 mg x (L x h)(-1) with an initial THF concentration of 360 mg x L(-1) when the concentration of CA and ACF was 3% and 1.5% respectively. The mechanical strength of the mobilized cells was also significantly improved with the addition of ACF. Compared to the free suspended cells, higher stable removal efficiency (more than 80%) of CA-ACF cells was detected under different conditions of temperature and pH. The feasibility of the newly designed matrix was also reflected by the repeated batch degradation which showed that the removal activity decreased insignificantly after 80 cycles with the modified reaction system (PNS).


Assuntos
Furanos/química , Pseudomonas oleovorans/metabolismo , Alginatos/química , Biodegradação Ambiental , Células Imobilizadas/microbiologia , Carvão Vegetal/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química
18.
Prep Biochem Biotechnol ; 43(7): 649-67, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23768111

RESUMO

Pseudomonas oleovorans PAMD_1 produced an intracellular azoreductase as the more prominent enzyme that reduces the azo bridge during the azo dye decolorization process. In order to optimize the expression of azoreductase, statistically based experiments were applied. Eleven significant factors were screened on decolorization activity using Plackett-Burman design. Dye, NADH, glucose, and peptone were identified as having highest positive influence on the decolorization activity. Central composite design of response surface methodology was employed for the concerted effect of these four factors on decolorization activity. This method showed that the optimum medium containing dye (200 mg L(-1)), NADH (1.14 mM), glucose (2.07 g L(-1)), and peptone (6.44 g L(-1)) for the decolorization of Orange II up to 87% in 48 hr. The applied methodology was validated through the adequacy and accuracy of the overall experiments, and the results proved that the applied methods were most effective. Further, the enzyme was purified ninefold with 16% yield by anion-exchange chromatography and a specific activity of 26 U mg(-1). The purified enzyme with a molecular mass of 29,000 Da gave a single band on sodium dodecyl sulfate (SDS) gel, and the degradation products sulfanilic acid and 1-amino-2-napthol of Orange II by azoreductase were analyzed by using an ultraviolet-visible (UV-Vis) spectrophotometer and hish-performance liquid chromatography (HPLC).


Assuntos
Biodegradação Ambiental , NADH NADPH Oxirredutases/química , NADH NADPH Oxirredutases/isolamento & purificação , Pseudomonas oleovorans/enzimologia , Compostos Azo/síntese química , Compostos Azo/química , Benzenossulfonatos/síntese química , Benzenossulfonatos/química , Corantes/química , Corantes/isolamento & purificação , Humanos , Cinética , NADH NADPH Oxirredutases/metabolismo
19.
Bioresour Technol ; 139: 87-93, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23644074

RESUMO

A novel entrapment matrix, calcium alginate (CA) coupled with activated carbon fiber (ACF), was prepared to immobilize Pseudomonas oleovorans DT4 for degrading tetrahydrofuran (THF). The addition of 1.5% ACF increased the adsorption capacity of the immobilized bead, thus resulting in an enhanced average removal rate of 30.3mg/(Lh). The synergism between adsorption and biodegradation was observed in the hybrid CA-ACF beads instead of in the system comprising CA beads and freely suspended ACF. The effective diffusion coefficient of the CA-ACF bead was not significantly affected by bead size, but the bead's value of 1.14×10(-6)cm(2)/s (for the bead diameter of 0.4 cm) was larger than that of the CA bead by almost one order of magnitude based on the intraparticle diffusion-reaction kinetics analysis. Continuous treatment of the THF-containing wastewater was succeeded by CA-ACF immobilized cells in a packed-bed reactor for 54 d with a >90% removal efficiency.


Assuntos
Alginatos/farmacologia , Carbono/farmacologia , Carvão Vegetal/farmacologia , Furanos/metabolismo , Microesferas , Pseudomonas oleovorans/citologia , Pseudomonas oleovorans/metabolismo , Adsorção , Biodegradação Ambiental/efeitos dos fármacos , Biomassa , Reatores Biológicos/microbiologia , Fibra de Carbono , Células Imobilizadas/citologia , Células Imobilizadas/efeitos dos fármacos , Células Imobilizadas/metabolismo , DNA Ribossômico/genética , Eletroforese em Gel de Gradiente Desnaturante , Difusão , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/farmacologia , Pseudomonas oleovorans/efeitos dos fármacos , Pseudomonas oleovorans/genética , Soluções
20.
Enzyme Microb Technol ; 50(6-7): 293-7, 2012 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-22500895

RESUMO

PHA synthase is the key enzyme involved in the biosynthesis of microbial polymers, polyhydroxyalkanoates (PHA). In this study, we created a hybrid library of PHA synthase gene with different crossover points by an incremental truncation method between the C-terminal fragments of the phaC(Cn) (phaC from Cupriavidus necator) and the N-terminal fragments of the phaC1(Pa) (phaC from Pseudomonas aeruginosa). As the truncation of the hybrid enzyme increased, the in vivo PHB synthesis ability of the hybrids declined gradually. PHA synthase PhaC(Cn) with a deletion on N-terminal up to 83 amino acid residues showed no synthase activity. While with the removal of up to 270 amino acids from the N-terminus, the activity of the truncated PhaC(Cn) could be complemented by the N-terminus of PhaC1(Pa). Three of the hybrid enzymes W188, W235 and W272 (named by the deleted nucleic acid number) were found to have altered product specificities.


Assuntos
Aciltransferases/genética , Cupriavidus necator/enzimologia , Engenharia Genética/métodos , Pseudomonas oleovorans/enzimologia , Deleção de Sequência , Aciltransferases/metabolismo , Biotecnologia , Cupriavidus necator/genética , Poliésteres/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Especificidade por Substrato
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