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Pesquisa : B03.440.400.425.625.625.223 [Categoria DeCS]
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  1 / 14 MEDLINE  
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[PMID]:28410434
[Au] Autor:Yamada M; Hashimoto Y; Kumano T; Tsujimura S; Kobayashi M
[Ad] Endereço:Institute of Applied Biochemistry and Graduate School of Life and Environmental Sciences, The University of Tsukuba, Tsukuba, Ibaraki, Japan.
[Ti] Título:New function of aldoxime dehydratase: Redox catalysis and the formation of an unexpected product.
[So] Source:PLoS One;12(4):e0175846, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In general, hemoproteins are capable of catalyzing redox reactions. Aldoxime dehydratase (OxdA), which is a unique heme-containing enzyme, catalyzes the dehydration of aldoximes to the corresponding nitriles. Its reaction is a rare example of heme directly activating an organic substrate, unlike the utilization of H2O2 or O2 as a mediator of catalysis by other heme-containing enzymes. While it is unknown whether OxdA catalyzes redox reactions or not, we here for the first time detected catalase activity (which is one of the redox activities) of wild-type OxdA, OxdA(WT). Furthermore, we constructed a His320 → Asp mutant of OxdA [OxdA(H320D)], and found it exhibits catalase activity. Determination of the kinetic parameters of OxdA(WT) and OxdA(H320D) revealed that their Km values for H2O2 were similar to each other, but the kcat value of OxdA(H320D) was 30 times higher than that of OxdA(WT). Next, we examined another redox activity and found it was the peroxidase activity of OxdAs. While both OxdA(WT) and OxdA(H320D) showed the activity, the activity of OxdA(H320D) was dozens of times higher than that of OxdA(WT). These findings demonstrated that the H320D mutation enhances the peroxidase activity of OxdA. OxdAs (WT and H320D) were found to catalyze another redox reaction, a peroxygenase reaction. During this reaction of OxdA(H320D) with 1-methoxynaphthalene as a substrate, surprisingly, the reaction mixture changed to a color different from that with OxdA(WT), which was due to the known product, Russig's blue. We purified and identified the new product as 1-methoxy-2-naphthalenol, which has never been reported as a product of the peroxygenase reaction, to the best of our knowledge. These findings indicated that the H320D mutation not only enhanced redox activities, but also significantly altered the hydroxylation site of the substrate.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Hidroliases/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Biocatálise
Cromatografia Líquida de Alta Pressão
Guaiacol/química
Hidroliases/química
Hidroliases/genética
Peróxido de Hidrogênio/química
Peróxido de Hidrogênio/metabolismo
Cinética
Espectrometria de Massas
Mutagênese Sítio-Dirigida
Naftalenos/análise
Naftalenos/química
Naftalenos/metabolismo
Oxirredução
Pseudomonas chlororaphis/enzimologia
Proteínas Recombinantes/biossíntese
Proteínas Recombinantes/genética
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Naphthalenes); 0 (Recombinant Proteins); 6JKA7MAH9C (Guaiacol); BBX060AN9V (Hydrogen Peroxide); DG2EOL57LF (1-methoxynaphthalene); EC 4.2.1.- (Hydro-Lyases); EC 4.2.1.- (aldoxime dehydratase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170415
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0175846


  2 / 14 MEDLINE  
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[PMID]:28239068
[Au] Autor:Morohoshi T; Yamaguchi T; Xie X; Wang WZ; Takeuchi K; Someya N
[Ad] Endereço:Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University.
[Ti] Título:Complete Genome Sequence of Pseudomonas chlororaphis subsp. aurantiaca Reveals a Triplicate Quorum-Sensing Mechanism for Regulation of Phenazine Production.
[So] Source:Microbes Environ;32(1):47-53, 2017 Mar 31.
[Is] ISSN:1347-4405
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Pseudomonas chlororaphis subsp. aurantiaca StFRB508 regulates phenazine production through N-acyl-l-homoserine lactone (AHL)-mediated quorum sensing. Two sets of AHL-synthase and AHL-receptor genes, phzI/phzR and aurI/aurR, have been identified from the incomplete draft genome of StFRB508. In the present study, the complete genome of StFRB508, comprising a single chromosome of 6,997,933 bp, was sequenced. The complete genome sequence revealed the presence of a third quorum-sensing gene set, designated as csaI/csaR. An LC-MS/MS analysis revealed that StFRB508 produced six types of AHLs, with the most important AHL being N-(3-hydroxyhexanoyl)-l-homoserine lactone (3-OH-C6-HSL). PhzI mainly catalyzed the biosynthesis of 3-OH-C6-HSL, while AurI and CsaI catalyzed that of N-hexanoyl-l-homoserine lactone and N-(3-oxohexanoyl)-l-homoserine lactone, respectively. A mutation in phzI decreased phenazine production, whereas that in aurI or csaI did not. A phzI aurI csaI triple mutant (508ΔPACI) did not produce phenazine. Phenazine production by 508ΔPACI was stimulated by exogenous AHLs and 3-OH-C6-HSL exerted the strongest effects on phenazine production at the lowest concentration tested (0.1 µM). The plant protection efficacy of 508ΔPACI against an oomycete pathogen was lower than that of wild-type StFRB508. These results demonstrate that the triplicate quorum-sensing system plays an important role in phenazine production by and the biocontrol activity of StFRB508.
[Mh] Termos MeSH primário: DNA Bacteriano/genética
Genoma Bacteriano
Fenazinas/metabolismo
Pseudomonas chlororaphis/genética
Percepção de Quorum
Análise de Sequência de DNA
Transdução de Sinais/genética
[Mh] Termos MeSH secundário: Acil-Butirolactonas/análise
Cromatografia Líquida
Análise Mutacional de DNA
DNA Bacteriano/química
Pseudomonas chlororaphis/química
Pseudomonas chlororaphis/metabolismo
Pseudomonas chlororaphis/fisiologia
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acyl-Butyrolactones); 0 (DNA, Bacterial); 0 (Phenazines); 0 (phenazine)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170414
[Lr] Data última revisão:
170414
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170228
[St] Status:MEDLINE
[do] DOI:10.1264/jsme2.ME16162


  3 / 14 MEDLINE  
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[PMID]:28082593
[Au] Autor:Chaikeeratisak V; Nguyen K; Khanna K; Brilot AF; Erb ML; Coker JK; Vavilina A; Newton GL; Buschauer R; Pogliano K; Villa E; Agard DA; Pogliano J
[Ad] Endereço:Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
[Ti] Título:Assembly of a nucleus-like structure during viral replication in bacteria.
[So] Source:Science;355(6321):194-197, 2017 01 13.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We observed the assembly of a nucleus-like structure in bacteria during viral infection. Using fluorescence microscopy and cryo-electron tomography, we showed that Pseudomonas chlororaphis phage 201φ2-1 assembled a compartment that separated viral DNA from the cytoplasm. The phage compartment was centered by a bipolar tubulin-based spindle, and it segregated phage and bacterial proteins according to function. Proteins involved in DNA replication and transcription localized inside the compartment, whereas proteins involved in translation and nucleotide synthesis localized outside. Later during infection, viral capsids assembled on the cytoplasmic membrane and moved to the surface of the compartment for DNA packaging. Ultimately, viral particles were released from the compartment and the cell lysed. These results demonstrate that phages have evolved a specialized structure to compartmentalize viral replication.
[Mh] Termos MeSH primário: Fagos de Pseudomonas/fisiologia
Pseudomonas chlororaphis/virologia
Montagem de Vírus
[Mh] Termos MeSH secundário: Capsídeo/metabolismo
Proteínas do Capsídeo/biossíntese
Proteínas do Capsídeo/genética
Microscopia Crioeletrônica
Citoplasma/ultraestrutura
Citoplasma/virologia
DNA Viral/biossíntese
Microscopia de Fluorescência
Fagos de Pseudomonas/genética
Pseudomonas chlororaphis/ultraestrutura
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Capsid Proteins); 0 (DNA, Viral)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170114
[St] Status:MEDLINE
[do] DOI:10.1126/science.aal2130


  4 / 14 MEDLINE  
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[PMID]:27974729
[Au] Autor:Shahid I; Rizwan M; Baig DN; Saleem RS; Malik KA; Mehnaz S
[Ad] Endereço:Department of Biological Sciences, Forman Christian College (A Chartered University), Lahore 54600, Pakistan.
[Ti] Título:Secondary Metabolites Production and Plant Growth Promotion by and Strains Isolated from Cactus, Cotton, and Para Grass.
[So] Source:J Microbiol Biotechnol;27(3):480-491, 2017 Mar 28.
[Is] ISSN:1738-8872
[Cp] País de publicação:Korea (South)
[La] Idioma:eng
[Ab] Resumo:Fluorescent pseudomonads have been isolated from halophytes, mesophytes, and xerophytes of Pakistan. Among these, eight isolates, GS-1, GS-3, GS-4, GS-6, GS-7, FS-2 (cactus), ARS-38 (cotton), and RP-4 (para grass), showed antifungal activity and were selected for detailed study. Based on biochemical tests and 16S rRNA gene sequences, these were identified as strains of subsp. and . Secondary metabolites of these strains were analyzed by LC-MS. Phenazine-1-carboxylic acid (PCA), 2-hydroxy-phenazine, Cyclic Lipopeptide (white line-inducing principle (WLIP)), and lahorenoic acid A were detected in variable amounts in these strains. PB-St2 was used as a reference as it is known for the production of these compounds. The and genes were amplified to assure that production of these compounds is not an artifact. Indole acetic acid production was confirmed and quantified by HPLC. HCN and siderophore production by all strains was observed by plate assays. These strains did not solubilize phosphate, but five strains were positive for zinc solubilization. Wheat seedlings were inoculated with these strains to observe their effect on plant growth. strains PB-St2 and GS-6 and RP-4 significantly increased both root and shoot dry weights, as compared with uninoculated plants. However, strains FS-2 and ARS-38 significantly increased root and shoot dry weights, respectively. All strains except PB-St2 and ARS-38 significantly increased the root length. This is the first report of the isolation of from cotton and cactus, from para grass, WLIP and lahorenoic acid A production by , and zinc solubilization by and .
[Mh] Termos MeSH primário: Cactaceae/crescimento & desenvolvimento
Cactaceae/microbiologia
Gossypium/crescimento & desenvolvimento
Gossypium/microbiologia
Poaceae/crescimento & desenvolvimento
Poaceae/microbiologia
Pseudomonas chlororaphis/metabolismo
Pseudomonas/metabolismo
Metabolismo Secundário
[Mh] Termos MeSH secundário: Antifúngicos/metabolismo
Antifúngicos/farmacologia
Produtos Biológicos/metabolismo
Produtos Biológicos/farmacologia
Cromatografia Líquida
Espectrometria de Massas
Metaboloma
Metabolômica/métodos
Testes de Sensibilidade Microbiana
Pseudomonas/classificação
Pseudomonas/genética
Pseudomonas/isolamento & purificação
Pseudomonas chlororaphis/classificação
Pseudomonas chlororaphis/genética
Pseudomonas chlororaphis/isolamento & purificação
RNA Ribossômico 16S/genética
Triticum/crescimento & desenvolvimento
Triticum/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antifungal Agents); 0 (Biological Products); 0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170406
[Lr] Data última revisão:
170406
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161216
[St] Status:MEDLINE
[do] DOI:10.4014/jmb.1601.01021


  5 / 14 MEDLINE  
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[PMID]:27926818
[Au] Autor:Yu JM; Wang D; Pierson LS; Pierson EA
[Ad] Endereço:1​Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77943-2133, USA.
[Ti] Título:Disruption of MiaA provides insights into the regulation of phenazine biosynthesis under suboptimal growth conditions in Pseudomonas chlororaphis 30-84.
[So] Source:Microbiology;163(1):94-108, 2017 Jan.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Many products of secondary metabolism are activated by quorum sensing (QS), yet even at cell densities sufficient for QS, their production may be repressed under suboptimal growth conditions via mechanisms that still require elucidation. For many beneficial plant-associated bacteria, secondary metabolites such as phenazines are important for their competitive survival and plant-protective activities. Previous work established that phenazine biosynthesis in Pseudomonas chlororaphis 30-84 is regulated by the PhzR/PhzI QS system, which in turn is regulated by transcriptional regulator Pip, two-component system RpeA/RpeB and stationary phase/stress sigma factor RpoS. Disruption of MiaA, a tRNA modification enzyme, altered primary metabolism and growth leading to widespread effects on secondary metabolism, including reduced phenazine production and oxidative stress tolerance. Thus, the miaA mutant provided the opportunity to examine the regulation of phenazine production in response to altered metabolism and growth or stress tolerance. Despite the importance of MiaA for translation efficiency, the most significant effect of miaA disruption on phenazine production was the reduction in the transcription of phzR, phzI and pip, whereas neither the transcription nor translation of RpeB, a transcriptional regulator of pip, was affected. Constitutive expression of rpeB or pip in the miaA mutant completely restored phenazine production, but it resulted in further growth impairment. Constitutive expression of RpoS alleviated sensitivity to oxidative stress resulting from RpoS translation inefficiency in the miaA mutant, but it did not restore phenazine production. Our results support the model that cells curtail phenazine biosynthesis under suboptimal growth conditions via RpeB/Pip-mediated regulation of QS.
[Mh] Termos MeSH primário: Alquil e Aril Transferases/genética
Regulação Bacteriana da Expressão Gênica/genética
Estresse Oxidativo/fisiologia
Fenazinas/metabolismo
Pseudomonas chlororaphis/crescimento & desenvolvimento
Percepção de Quorum/genética
[Mh] Termos MeSH secundário: Proteínas de Bactérias/biossíntese
Proteínas de Bactérias/genética
Peptídeo Sintases/genética
Pseudomonas chlororaphis/genética
Pseudomonas chlororaphis/metabolismo
Percepção de Quorum/fisiologia
Fator sigma/biossíntese
Fator sigma/genética
Transativadores/genética
Transcrição Genética/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Phenazines); 0 (PhzI protein, Pseudomonas sp.); 0 (PhzR protein, Pseudomonas); 0 (Sigma Factor); 0 (Trans-Activators); 0 (phenazine); 0 (sigma factor KatF protein, Bacteria); EC 2.5.- (Alkyl and Aryl Transferases); EC 2.5.1.27 (adenylate isopentenyltransferase); EC 6.3.2.- (Peptide Synthases); EC 6.3.2.- (pipecolate-activating enzyme)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161208
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000409


  6 / 14 MEDLINE  
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[PMID]:27998371
[Au] Autor:Nandi M; Selin C; Brawerman G; Fernando WG; de Kievit TR
[Ad] Endereço:1​Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
[Ti] Título:The global regulator ANR is essential for Pseudomonas chlororaphis strain PA23 biocontrol.
[So] Source:Microbiology;162(12):2159-2169, 2016 Dec.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Pseudomonas chlororaphis PA23 is a biocontrol agent capable of protecting canola from stem rot disease caused by the fungus Sclerotinia sclerotiorum. The focus of the current study was to elucidate the role of the transcriptional regulator ANR in the biocontrol capabilities of this bacterium. An anr mutant was created, PA23anr, that was devoid antifungal activity. In other pseudomonads, ANR is essential for regulating HCN production. Characterization of PA23anr revealed that, in addition to HCN, ANR controls phenazine (PHZ), pyrrolnitrin (PRN), protease and autoinducer (AHL) signal molecule production. In gene expression studies, hcnA, phzA, prnA and phzI were found to be downregulated, consistent with our endproduct analysis. Because the phenotype of PA23anr closely resembles that of quorum sensing (QS)-deficient strains, we explored whether there is a connection between ANR and the PhzRI QS system. Both phzI and phzR are positively regulated by ANR, whereas PhzR represses anr transcription. Complementation of PA23anr with pUCP-phzR, C6-HSL or both yielded no change in phenotype. Conversely, PA23phzR harbouring pUCP23-anr exhibited partial-to-full restoration of antifungal activity, HCN, PRN and AHL production together with hcnA, prnA, phzI and rpoS expression. PHZ and protease production remained unchanged indicating that ANR can complement the QS-deficient phenotype with respect to some but not all traits. Our experiments were conducted at atmospheric O2 levels underscoring the fact that ANR has a profound effect on PA23 physiology under aerobic conditions.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Regulação Bacteriana da Expressão Gênica
Doenças das Plantas/microbiologia
Pseudomonas chlororaphis/metabolismo
[Mh] Termos MeSH secundário: Ascomicetos/fisiologia
Proteínas de Bactérias/genética
Fenazinas/metabolismo
Pseudomonas chlororaphis/genética
Transativadores/genética
Transativadores/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Phenazines); 0 (Trans-Activators)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170804
[Lr] Data última revisão:
170804
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161222
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000391


  7 / 14 MEDLINE  
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[PMID]:27861617
[Au] Autor:Bauer JS; Hauck N; Christof L; Mehnaz S; Gust B; Gross H
[Ad] Endereço:Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany.
[Ti] Título:The Systematic Investigation of the Quorum Sensing System of the Biocontrol Strain Pseudomonas chlororaphis subsp. aurantiaca PB-St2 Unveils aurI to Be a Biosynthetic Origin for 3-Oxo-Homoserine Lactones.
[So] Source:PLoS One;11(11):e0167002, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The shoot endophytic biocontrol strain Pseudomonas chlororaphis subsp. aurantiaca PB-St2 produces a wide range of exoproducts, including enzymes and antibiotics. The production of exoproducts is commonly tightly regulated. In order to get a deeper insight into the regulatory network of PB-St2, the strain was systematically investigated regarding its quorum sensing systems, both on the genetic and metabolic level. The genome analysis of PB-St2 revealed the presence of four putative acyl homoserine lactone (AHL) biosynthesis genes: phzI, csaI, aurI, and hdtS. LC-MS/MS analyses of the crude supernatant extracts demonstrated that PB-St2 produces eight AHLs. In addition, the concentration of all AHL derivatives was quantified time-resolved in parallel over a period of 42 h during the growth of P. aurantiaca PB-St2, resulting in production curves, which showed differences regarding the maximum levels of the AHLs (14.6 nM- 1.75 µM) and the production period. Cloning and heterologous overexpression of all identified AHL synthase genes in Escherichia coli proved the functionality of the resulting synthases PhzI, CsaI, and AurI. A clear AHL production pattern was assigned to each of these three AHL synthases, while the HdtS synthase did not lead to any AHL production. Furthermore, the heterologous expression study demonstrated unequivocally and for the first time that AurI directs the synthesis of two 3-oxo-AHLs.
[Mh] Termos MeSH primário: 4-Butirolactona/análogos & derivados
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Pseudomonas/fisiologia
Percepção de Quorum
[Mh] Termos MeSH secundário: 4-Butirolactona/biossíntese
Cromatografia Líquida
Metabolômica/métodos
Família Multigênica
Fenazinas/metabolismo
Pseudomonas chlororaphis/fisiologia
Percepção de Quorum/genética
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Phenazines); 1192-20-7 (homoserine lactone); OL659KIY4X (4-Butyrolactone)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170626
[Lr] Data última revisão:
170626
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161119
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0167002


  8 / 14 MEDLINE  
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[PMID]:27708055
[Au] Autor:Schellenberger U; Oral J; Rosen BA; Wei JZ; Zhu G; Xie W; McDonald MJ; Cerf DC; Diehn SH; Crane VC; Sandahl GA; Zhao JZ; Nowatzki TM; Sethi A; Liu L; Pan Z; Wang Y; Lu AL; Wu G; Liu L
[Ad] Endereço:DuPont Pioneer, Hayward, CA 94545, USA.
[Ti] Título:A selective insecticidal protein from Pseudomonas for controlling corn rootworms.
[So] Source:Science;354(6312):634-637, 2016 Nov 04.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The coleopteran insect western corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte) is a devastating crop pest in North America and Europe. Although crop plants that produce Bacillus thuringiensis (Bt) proteins can limit insect infestation, some insect populations have evolved resistance to Bt proteins. Here we describe an insecticidal protein, designated IPD072Aa, that is isolated from Pseudomonas chlororaphis. Transgenic corn plants expressing IPD072Aa show protection from WCR insect injury under field conditions. IPD072Aa leaves several lepidopteran and hemipteran insect species unaffected but is effective in killing WCR larvae that are resistant to Bt proteins produced by currently available transgenic corn. IPD072Aa can be used to protect corn crops against WCRs.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Coleópteros/metabolismo
Resistência a Inseticidas
Inseticidas/metabolismo
Doenças das Plantas/parasitologia
Raízes de Plantas/parasitologia
Plantas Geneticamente Modificadas/parasitologia
Pseudomonas chlororaphis/metabolismo
Zea mays/parasitologia
[Mh] Termos MeSH secundário: Animais
Proteínas de Bactérias/classificação
Proteínas de Bactérias/genética
Coleópteros/genética
Produtos Agrícolas/genética
Produtos Agrícolas/parasitologia
Endotoxinas/genética
Endotoxinas/metabolismo
Proteínas Hemolisinas/genética
Proteínas Hemolisinas/metabolismo
Filogenia
Raízes de Plantas/genética
Plantas Geneticamente Modificadas/genética
Zea mays/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Endotoxins); 0 (Hemolysin Proteins); 0 (Insecticides); 0 (insecticidal crystal protein, Bacillus Thuringiensis)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161007
[St] Status:MEDLINE


  9 / 14 MEDLINE  
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[PMID]:27470070
[Au] Autor:Liu K; Hu H; Wang W; Zhang X
[Ad] Endereço:State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
[Ti] Título:Genetic engineering of Pseudomonas chlororaphis GP72 for the enhanced production of 2-Hydroxyphenazine.
[So] Source:Microb Cell Fact;15(1):131, 2016 Jul 28.
[Is] ISSN:1475-2859
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The biocontrol strain Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere synthesizes three antifungal phenazine compounds, 2-Hydroxyphenazine (2-OH-PHZ), 2-hydroxy-phenazine-1-carboxylic acid (2-OH-PCA) and phenazine-1-carboxylic acid (PCA). PCA has been a commercialized antifungal pesticide registered as "Shenqinmycin" in China since 2011. It is found that 2-OH-PHZ shows stronger fungistatic and bacteriostatic activity to some pathogens than PCA. 2-OH-PHZ could be developed as a potential antifungal pesticide. But the yield of 2-OH-PHZ generally is quite low, such as P. chlororaphis GP72, the production of 2-OH-PHZ by the wide-type strain is only 4.5 mg/L, it is necessary to enhance the yield of 2-OH-PHZ for its application in agriculture. RESULTS: Different strategies were used to improve the yield of 2-OH-PHZ: knocking out the negative regulatory genes, enhancing the shikimate pathway, deleting the competing pathways of 2-OH-PHZ synthesis based on chorismate, and improving the activity of PhzO which catalyzes the conversion of PCA to 2-OH-PHZ, although the last two strategies did not give us satisfactory results. In this study, four negative regulatory genes (pykF, rpeA, rsmE and lon) were firstly knocked out of the strain GP72 genome stepwise. The yield of 2-OH-PHZ improved more than 60 folds and increased from 4.5 to about 300 mg/L. Then six key genes (ppsA, tktA, phzC, aroB, aroD and aroE) selected from the gluconeogenesis, pentose phosphate and shikimate pathways which used to enhance the shikimate pathway were overexpressed to improve the production of 2-OH-PHZ. At last a genetically engineered strain that increased the 2-OH-PHZ production by 99-fold to 450.4 mg/L was obtained. CONCLUSIONS: The 2-OH-PHZ production of P. chlororaphis GP72 was greatly improved through disruption of four negative regulatory genes and overexpression of six key genes, and it is shown that P. chlororaphis GP72 could be modified as a potential cell factory to produce 2-OH-PHZ and other phenazine biopesticides by genetic and metabolic engineering.
[Mh] Termos MeSH primário: Antifúngicos/metabolismo
Pseudomonas chlororaphis/genética
[Mh] Termos MeSH secundário: Antifúngicos/farmacologia
Regulação Bacteriana da Expressão Gênica
Genes Bacterianos
Genes Reguladores
Engenharia Genética
Fenazinas/metabolismo
Fenazinas/farmacologia
Pseudomonas chlororaphis/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antifungal Agents); 0 (Phenazines); 4190-95-8 (2-hydroxyphenazine)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170321
[Lr] Data última revisão:
170321
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160730
[St] Status:MEDLINE
[do] DOI:10.1186/s12934-016-0529-0


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[PMID]:27421102
[Au] Autor:Lopes AR; Sousa VM; Estevinho BN; Leite JP; Moreira NFF; Gales L; Rocha F; Nunes OC
[Ad] Endereço:LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
[Ti] Título:Production of microparticles of molinate degrading biocatalysts using the spray drying technique.
[So] Source:Chemosphere;161:61-68, 2016 Oct.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Previous studies demonstrated the capability of mixed culture DC1 to mineralize the thiocarbamate herbicide molinate through the activity of molinate hydrolase (MolA). Because liquid suspensions are not compatible with long-term storage and are not easy to handle when bioremediation strategies are envisaged, in this study spray drying was evaluated as a cost-effective method to store and transport these molinate biocatalysts. Microparticles of mixed culture DC1 (DC1) and of cell free crude extracts containing MolA (MA) were obtained without any carrier polymer, and with calcium alginate (CA) or modified chitosan (MCt) as immobilizing agents. All the DC1 microparticles showed high molinate degrading activity upon storage for 6 months, or after 9 additions of ∼0.4 mM molinate over 1 month. The DC1-MCt microparticles were those with the highest survival rate and lowest heterogeneity. For MA microparticles, only MA-MCt degraded molinate. However, its Vmax was only 1.4% of that of the fresh cell free extract (non spray dried). The feasibility of using the DC1-MCt and MA-MCt microparticles in bioaugmentation processes was assessed in river water microcosms, using mass (g):volume (L) ratios of 1:13 and 1:0.25, respectively. Both type of microparticles removed ∼65-75% of the initial 1.5 mg L(-1) molinate, after 7 days of incubation. However, only DC1-MCt microparticles were able to degrade this environmental concentration of molinate without disturbing the native bacterial community. These results suggest that spray drying can be successfully used to produce DC1-MCt microparticles to remediate molinate polluted sites through a bioaugmentation strategy.
[Mh] Termos MeSH primário: Azepinas/análise
Quitosana/química
Herbicidas/análise
Hidrolases/química
Tiocarbamatos/análise
Poluentes Químicos da Água/análise
Purificação da Água/métodos
[Mh] Termos MeSH secundário: Actinobacteria/enzimologia
Actinobacteria/crescimento & desenvolvimento
Biocatálise
Biodegradação Ambiental
Composição de Medicamentos
Tamanho da Partícula
Pseudomonas chlororaphis/enzimologia
Pseudomonas chlororaphis/crescimento & desenvolvimento
Stenotrophomonas maltophilia/enzimologia
Stenotrophomonas maltophilia/crescimento & desenvolvimento
Propriedades de Superfície
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Azepines); 0 (Herbicides); 0 (Thiocarbamates); 0 (Water Pollutants, Chemical); 68N5G08DJQ (molinate); 9012-76-4 (Chitosan); EC 3.- (Hydrolases)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170929
[Lr] Data última revisão:
170929
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160716
[St] Status:MEDLINE



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