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1.
Curr Microbiol ; 80(1): 34, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36508041

RESUMO

A Gram-negative, facultative anaerobic bacterial strain, designated YIM B02556T, was isolated from the root of Paris polyphylla Smith var. yunnanensis collected from Yunnan Province, southwest China. By using a polyphasic approach, its taxonomic position was investigated. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM B02556T belonged to the genus Azospirillum and the 16S rRNA gene sequence similarity values of strain YIM B02556T to the type strains of members of this genus ranged from 94.9 to 98.3%. Overall genome relatedness index (OGRI) analysis estimated based on average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between YIM B02556T and other Azospirillum species type strains were <90.8% and <37.8%, lower than the limit of species circumscription. Cells of the strain were characterized as oxidase- and catalase-positive, with motility provided by flagella. The growth conditions of the strain were found to occur at 20-40 °C (optimum, 35 °C), and pH 6.0-9.5 (optimum, pH 7.5). Strain YIM B02556T can tolerate 2% NaCl concentration. Strain YIM B02556T contained Q-10 as the major ubiquinone. The major fatty acids were C18:1 ω7c and summed feature three (C16:1 ω7c and/or C16:1 ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Based on polyphasic analysis, strain YIM B02556T could be differentiated genotypically and phenotypically from recognized species of the genus Azospirillum. Therefore, the isolate represents a novel species, for which the name Azospirillum endophyticum is proposed. The type strain is YIM B02556T (=JCM 34631T=CGMCC 1.18654T).


Assuntos
Azospirillum , RNA Ribossômico 16S/genética , Azospirillum/genética , Filogenia , Endófitos/genética , Composição de Bases , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Fosfolipídeos/análise , China , Ácidos Graxos/análise
2.
Arch Microbiol ; 204(1): 80, 2021 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-34954806

RESUMO

Strain W712T was isolated from rhizosphere soil of Nicotiana tabacum L. collected from Kunming, south-west China. Cells were Gram-staining negative, aerobic, motile and rod shaped. The isolate grew at 20-45 °C (optimum 30 °C), pH 6.0-8.0 (optimum pH 7.0) and in the presence of up to 3.0% (w/v) NaCl (optimum 1%, w/v). Ubiquinone-10 was the only respiratory quinone type. Polar lipids contained diphosphatidylglycerol, phosphatidylmehtylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified aminolipid. The major fatty acids were detected as summed feature 8 (C18:1 ω7c or C18:1 ω6c), summed feature 3 (C16:1 ω7c or C16:1 ω6c) and C18:1 2OH. The genomic DNA G + C content was 68.7%. The ANI values were 94.3%, 93.3% and 93.6% between Azospirillum baldaniorum Sp245T, Azospirillum brasilense ATCC 49958T, Azospirillum formosense CC-Nfb-7T and strain W712T, respectively, which were lower than the prokaryotic species delineation threshold of 95.0-96.0%. The digital DNA-DNA hybridization values between A. baldaniorum Sp245T, A. brasilense ATCC 49958T, A. formosense CC-Nfb-7T and strain W712T indicated that the candidate represents a novel genomic species. According to the phenotypic and genotypic characteristics, we propose that strain W712T warrants the assignment to a novel species, for which the name Azospirillum tabaci sp. nov. (type strain W712T = CGMCC 1.18567T = KCTC 82186T) is proposed.


Assuntos
Azospirillum , Rizosfera , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Nicotiana
3.
Syst Appl Microbiol ; 44(1): 126171, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33360414

RESUMO

Two nitrogen-fixing and heavy oil degrading strains, designated RWY-5-1-1T and ROY-1-1-2, were isolated from an oil production mixture from Yumen Oilfield in China. The 16S rRNA gene sequence showed they belong to Azospirillum and have less than 96.1 % pairwise similarity with each species in this genus. The average nucleotide identity and digital DNA-DNA hybridization values between them and other type strains of Azospirillum species were less than 75.69 % and 22.0 %, respectively, both below the species delineation threshold. Pan-genomic analysis showed that the novel isolate RWY-5-1-1T shared 2145 core gene families with other type strains in Azospirillum, and the number of strain-specific gene families was 1623, almost two times more than the number known from other species. Furthermore, genes related to nitrogenase, hydrocarbon degradation and biosurfactant production were found in the isolates' genomes. Also, this strain was capable of reducing acetylene to ethylene at a rate of 22nmol ethylene h-1 (108 cells) and degrading heavy oil at a rate of 36.2 %. The major fatty acids and polar lipids were summed feature 8 (C18:1ω7c/C18:1ω6c), and phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. Furthermore, a combination of phenotypic, chemotaxonomic, phylogenetic and genotypic data clearly indicated that strains RWY-5-1-1T and ROY-1-1-2 represent a novel species, for which the name Azospirillum oleiclasticum sp. nov. is proposed. The type strain is RWY-5-1-1T (=CGMCC 1.13426T =KCTC 72259 T). Azospirillum novel strains with the ability of heavy oil degradation associated with the promotion of plant growth has never been reported to date.


Assuntos
Azospirillum/classificação , Fixação de Nitrogênio , Campos de Petróleo e Gás/microbiologia , Petróleo/metabolismo , Filogenia , Azospirillum/isolamento & purificação , Técnicas de Tipagem Bacteriana , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
4.
Int J Syst Evol Microbiol ; 70(1): 550-554, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31651377

RESUMO

A novel Gram-staining negative, aerobic, motile by flagellum, rod-shaped bacterium, designated CFH 70021T was isolated from a hot spring soil sample collected from Tengchong, Yunnan province, PR China. Growth of CFH 70021T occurred at 15-50 °C (optimum 50 °C), pH 5.0-7.0 (optimum pH 7.0) and with 0-3.0 % (w/v) NaCl (optimum 0 %, w/v). The genome of CFH 70021T consisted of four complete circular chromosomes and five plasmids, the genomic DNA G+C content was 69.3 mol%. Comparison of the 16S rRNA gene sequences indicated that CFH 70021T represented a member of the genus Azospirillum and showed close relationship with the type strains of Azospirillum agricola CC-HIH038T (97.8 %), Azospirillum rugosum IMMIB AFH-6T (97.6 %), Azospirillum doebereinerae GSF71T (97.6 %), Azospirillum thiophilum DSM 21654T (97.4 %) and Azospirillum picis IMMIB TAR-3T (97.2 %). The polar lipids of CFH 70021T contained diphosphatidylglycerol, phosphatidylmehtylethanolamine, phosphatidylglycerol, phosphatidylcholine, two aminolipids and an unidentified phospholipid. The predominant cellular fatty acids (>10 %) included C19:0cyclo ω8c (11.4 %), C16 : 0 (27.6 %) and summed feature 8 (C18:1ω7c/C18:1ω6c, 40.9 %). The major isoprenoid quinone was Q-10. On the basis of the low ANIb result (<78 %) and different phenotypic and chemotaxonomic characters, we conclude that strain CFH 70021T represents a novel member of the genus Azospirillum, for which the name Azospirillum thermophilum sp. nov. is proposed. The type strain is CFH 70021T (=KCTC 62259T= CCTCC AB2018121T).


Assuntos
Azospirillum/classificação , Fontes Termais/microbiologia , Filogenia , Microbiologia do Solo , Azospirillum/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
5.
PLoS One ; 13(8): e0201738, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30096207

RESUMO

Safflower is an important industrial oil seed and bioenergy crop in semi-arid subtropical regions due to its potential to grow on marginal land and having good percentage of seed oil contents which is an important parameter for biofuel production. However, it is an ignored crop in Pakistan. In order to improve the crop productivity and reduce the use of agrochemicals for sustainable biodiesel feedstock production, an experiment was conducted for two years to improve the fatty acid composition and oil quality of Carthamus tinctorius L. (safflower) by the inoculation of Azospirillum and Azotobacter alone as well as in combined application with nitrogen and phosphate (NP) fertilizers on cultivars Thori and Saif-32 under field conditions. Separation and quantification of fatty acids were done on precise comprehensive two-dimensional gas chromatography (GC×GC). The results showed that fatty acid profile specifically monounsaturated fatty acids i-e oleic acid (C18:1) was significantly improved by Azospirillum supplemented with the quarter dose of NP fertilizers (SPQ) with concomitant decrease in polyunsaturated fatty acids by the respective treatment. Oil quality attributes such as acid value, saponification number, iodine value, refractive index and free fatty acid contents were reduced by the application of Azotobacter and Azospirillum in combination with half and quarter doses of NP fertilizers treatments (BTH, SPH, BTQ and SPQ). The reduction in these variables is positively linked with improved biodiesel yield and quality. It can be concluded that application of Azospirillum and Azotobacter not only reduced the use of NP fertilizers up to 50%-75% but also improved the oil quality in order to obtain environment friendly, sustainable and green fuel.


Assuntos
Agricultura/métodos , Biocombustíveis/análise , Fertilizantes , Óleo de Cártamo/análise , Microbiologia do Solo , Azospirillum , Azotobacter , Carthamus tinctorius/química , Carthamus tinctorius/crescimento & desenvolvimento , Carthamus tinctorius/microbiologia , Ácidos Graxos/análise , Nitrogênio , Fosfatos , Especificidade da Espécie
6.
Biosci Biotechnol Biochem ; 82(9): 1522-1526, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29847205

RESUMO

A bacterial endophyte Azospirillum sp. B510 induces systemic disease resistance in the host without accompanying defense-related gene expression. To elucidate molecular mechanism of this induced systemic resistance (ISR), involvement of ethylene (ET) was examined using OsEIN2-knockdown mutant rice. Rice blast inoculation assay and gene expression analysis indicated that ET signaling is required for endophyte-mediated ISR in rice. ABBREVIATIONS: ACC: 1-aminocyclopropane-1-carboxylic acid; EIN2: ethylene-insensitive protein 2; ET: ethylene; ISR: induced systemic resistance; JA: jasmonic acid; RNAi: RNA interference; SA: salicylic acid; SAR: systemic acquired resistance.


Assuntos
Azospirillum/metabolismo , Etilenos/metabolismo , Oryza/microbiologia , Transdução de Sinais , Técnicas de Silenciamento de Genes , Oryza/genética
7.
Rev. biol. trop ; Rev. biol. trop;65(1): 21-30, Jan.-Mar. 2017. tab, ilus
Artigo em Espanhol | LILACS | ID: biblio-897522

RESUMO

ResumenLa industria petrolera ha generado derrames crónicos de petróleo y su acumulación en Gleysoles en zonas anegadas en el estado de Tabasco, en el sureste de México. El anegamiento es un factor que limita el uso de tecnologías de remediación por el alto costo y los bajos niveles de degradación del petróleo, sin embargo, Leersia hexandra Sw. es un pasto que crece en estas zonas contaminadas con petróleo intemperizado. El objetivo del estudio fue evaluar la densidad de bacterias, producción de biomasa vegetal y fitorremediación de L.hexandra en suelo contaminado con petróleos fresco e intemperizado, bajo condiciones experimentales de anegamiento. Se realizaron dos experimentos (E1 y E2) en un túnel de plástico. El E1 se basó en ocho dosis: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 y 180 000 mg kg-1 base seca (b.s.) de hidrocarburos totales de petróleo fresco (HTPF), y en el E2 se evaluaron cinco dosis: 14 173, 28 400, 50 598, 75 492 y 112 142 mg kg-1 b. s. de hidrocarburos totales de petróleo intemperizado (HTPI), con ocho repeticiones en cada experimento, además se utilizó un testigo con 2 607 mg kg-1 b. s. de HTP de origen biogénico. Las variables evaluadas a los tres y seis meses fueron 1) densidad microbiana de las bacterias fijadoras de nitrógeno de vida libre totales (BFN), del grupo Azospirillum (AZP) y Azotobacter (AZT), por cuenta viable en placa seriada; 2) producción de materia seca total (MS), se cuantificó por el peso seco por gravimetría, y 3) el porcentaje de descontaminación de los hidrocarburos (DSC) por extracción en equipo soxhlet. En suelos con HTPF, la población de BFN, AZP y AZT se estimuló hasta cinco veces más que el tratamiento testigo a los tres y seis meses; sin embargo, concentraciones de 150 000 y 180 000 mg kg-1 b. s. inhibieron entre un 70 y 89 % la densidad bacteriana. A su vez, en suelos con PI, la inhibición se registró hasta en un 90 %, a excepción del tratamiento con 14 173 mg kg-1 b. s., el cual estimuló las BNF y AZT en 2 y 0.10 veces más que testigo, respectivamente. La producción de MS fue continua en los experimentos hasta los seis meses, con valores de 63 y 89 g en PF y PI, respectivamente; sin diferencias significativas con el testigo (p ≤ 0.05). El DSC alcanzó valores del 66 % al 87 % en HTPF como HTPI a los seis meses, respectivamente. Estos resultados demuestran la habilidad del L. hexandra para desarrollar una rizósfera con alta densidad de BFN, producir biomasa vegetal y fitorremediar Gleysoles con petróleo fresco e intemperizado en ambientes tropicales inundados.


Abstract:The oil industry has generated chronic oil spills and their accumulation in wetlands of the state of Tabasco, in Southeastern Mexico. Waterlogging is a factor that limits the use of remediation technologies because of its high cost and low levels of oil degradation. However, Leersia hexandra is a grass that grows in these contaminated areas with weathered oil. The aim of the study was to evaluate the bacteria density, plant biomass production and phytoremediation of L. hexandra in contaminated soil. For this, two experiments in plastic tunnel were performed with fresh (E1) and weathered petroleum (E2) under waterlogging experimental conditions. The E1 was based on eight doses: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 and 180 000 mg.kg-1 dry basis (d. b.) of total petroleum hydrocarbons fresh (TPH-F), and the E2, that evaluated five doses: 14 173, 28 400, 50 598, 75 492 and 112 142 mg. kg-1 d. b. of total petroleum hydrocarbons weathered (TPH-W); a control treatment with 2 607 mg.kg-1 d. b. was used. Each experiment, with eight replicates per treatment, evaluated after three and six months: a) microbial density of total free-living nitrogen-fixing bacteria (NFB) of Azospirillum (AZP) and Azotobacter group (AZT), for viable count in serial plate; b) dry matter production (DMP), quantified gravimetrically as dry weight of L. hexandra; and c) the decontamination percentage of hydrocarbons (PDH) by Soxhlet extraction. In soil with TPH-F, the NFB, AZP y AZT populations were stimulated five times more than the control both at the three and six months; however, concentrations of 150 000 and 180 000 mg.kg-1 d. b. inhibited the bacterial density between 70 and 89 %. Likewise, in soil with TPH-W, the FNB, AZP and AZT inhibitions were 90 %, with the exception of the 14 173 mg.kg-1 d. b. treatment, which stimulated the NFB and AZT in 2 and 0.10 times more than the control, respectively. The DMP was continued at the six months in the experiments, with values of 63 and 89 g in fresh and weathered petroleum, respectively; had no significant differences with the control (p≤0.05). The PDH reached values of 66 to 87 % both TPH-F and TPH-W at six months, respectively. These results demonstrated the ability the L. hexandra rhizosphere to stimulate the high NFB density, vegetal biomass production and phytoremediation of contaminated soils (with fresh and weathered petroleum), in a tropical waterlogging environment. Rev. Biol. Trop. 65 (1): 21-30. Epub 2017 March 01.


Assuntos
Poluentes do Solo/química , Biodegradação Ambiental , Poluição por Petróleo/prevenção & controle , Poaceae/microbiologia , Poaceae/química , Valores de Referência , Solo/química , Microbiologia do Solo , Azotobacter/crescimento & desenvolvimento , Fatores de Tempo , Petróleo/análise , Contagem de Colônia Microbiana , Reprodutibilidade dos Testes , Azospirillum/crescimento & desenvolvimento , Biomassa , Hidrocarbonetos/análise , Hidrocarbonetos/química
8.
Rev Biol Trop ; 65(1): 21-30, 2017 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-29465955

RESUMO

The oil industry has generated chronic oil spills and their accumulation in wetlands of the state of Tabasco, in Southeastern Mexico. Waterlogging is a factor that limits the use of remediation technologies because of its high cost and low levels of oil degradation. However, Leersia hexandra is a grass that grows in these contaminated areas with weathered oil. The aim of the study was to evaluate the bacteria density, plant biomass production and phytoremediation of L. hexandra in contaminated soil. For this, two experiments in plastic tunnel were performed with fresh (E1) and weathered petroleum (E2) under waterlogging experimental conditions. The E1 was based on eight doses: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 and 180 000 mg.kg-1 dry basis (d. b.) of total petroleum hydrocarbons fresh (TPH-F), and the E2, that evaluated five doses: 14 173, 28 400, 50 598, 75 492 and 112 142 mg. kg-1 d. b. of total petroleum hydrocarbons weathered (TPH-W); a control treatment with 2 607 mg.kg-1 d. b. was used. Each experiment, with eight replicates per treatment, evaluated after three and six months: a) microbial density of total free-living nitrogen-fixing bacteria (NFB) of Azospirillum (AZP) and Azotobacter group (AZT), for viable count in serial plate; b) dry matter production (DMP), quantified gravimetrically as dry weight of L. hexandra; and c) the decontamination percentage of hydrocarbons (PDH) by Soxhlet extraction. In soil with TPH-F, the NFB, AZP y AZT populations were stimulated five times more than the control both at the three and six months; however, concentrations of 150 000 and 180 000 mg.kg-1 d. b. inhibited the bacterial density between 70 and 89 %. Likewise, in soil with TPH-W, the FNB, AZP and AZT inhibitions were 90 %, with the exception of the 14 173 mg.kg-1 d. b. treatment, which stimulated the NFB and AZT in 2 and 0.10 times more than the control, respectively. The DMP was continued at the six months in the experiments, with values of 63 and 89 g in fresh and weathered petroleum, respectively; had no significant differences with the control (p≤0.05). The PDH reached values of 66 to 87 % both TPH-F and TPH-W at six months, respectively. These results demonstrated the ability the L. hexandra rhizosphere to stimulate the high NFB density, vegetal biomass production and phytoremediation of contaminated soils (with fresh and weathered petroleum), in a tropical waterlogging environment.


Assuntos
Biodegradação Ambiental , Poluição por Petróleo/prevenção & controle , Poaceae/química , Poaceae/microbiologia , Poluentes do Solo , Azospirillum/crescimento & desenvolvimento , Azotobacter/crescimento & desenvolvimento , Biomassa , Contagem de Colônia Microbiana , Hidrocarbonetos/análise , Hidrocarbonetos/química , Petróleo/análise , Valores de Referência , Reprodutibilidade dos Testes , Solo/química , Microbiologia do Solo , Poluentes do Solo/química , Fatores de Tempo
9.
Braz. j. microbiol ; Braz. j. microbiol;47(3): 542-550, July-Sept. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-788956

RESUMO

ABSTRACT The main objective of the present study was to isolate phytohormone-producing, phosphate-solubilizing strains of Azospirillum from wheat to be used as inoculants for plant growth promotion. Five Azospirillum strains were isolated from the rhizosphere of field-grown wheat (Triticum aestivum L.), and it was confirmed by BOX-polymerase chain reaction (PCR) that the isolates were different and not re-isolates of the same strain. Sequence analysis of the PCR-amplified 16S rRNA gene indicated that four isolates showed maximum similarity to Azospirillum brasilense and one isolate showed maximum similarity to Azospirillum zeae. This is the first report indicating the presence of an A. zeae like isolate in the wheat rhizosphere in Pakistan. The bacterial isolates were characterized for their plant growth-promoting traits, phosphate solubilization, and indole-3-acetic acid (IAA) production. None of the isolates showed phosphate solubilization activity in the commonly used Pikovskaya medium. However, all strains (except AzoK4) exhibited ability to solubilize tricalcium phosphate (TCP) in modified Pikovskaya medium in which sucrose was replaced by Na-malate, as well as in TCP-supplemented Luria-Bertani (LB) medium. Organic acids, such as acetic, citric, lactic, malic, and succinic acids, were detected in culture supernatants of the tested Azospirillum strains. All strains exhibited ability to produce IAA in the growth medium, except Azospirillum sp. AzoK1. Among the strains tested, the maximum IAA production (30.49 ± 1.04 mg L-1) and phosphate solubilization (105.50 ± 4.93 mg L-1) were shown by a pure culture of Azospirillum sp. AzoK2. In pot experiments, single-strain inocula of Azospirillum sp. AzoK1 and AzoK2 improved wheat plant growth.


Assuntos
Reguladores de Crescimento de Plantas/biossíntese , Triticum/microbiologia , Azospirillum/classificação , Azospirillum/fisiologia , Rizosfera , Paquistão , Filogenia , Análise de Sequência de DNA , Ácidos de Fósforo/metabolismo , Genes Bacterianos , Nitrogênio/metabolismo
10.
Int J Syst Evol Microbiol ; 66(3): 1453-1458, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26786719

RESUMO

A polyphasic approach was used to characterize a novel nitrogen-fixing bacterial strain, designated CC-HIH038T, isolated from cultivated soil in Taiwan. Cells of strain CC-HIH038T were Gram-stain-negative, facultatively aerobic and spiral-shaped, with motility provided by a single polar flagellum. The 16S rRNA gene sequence analysis of strain CC-HIH038T showed highest sequence similarity to Azospirillum doebereinerae (98.0 %), Azospirillum thiophilum (97.5 %), Azospirillum rugosum (97.4 %) and Azospirillum zeae (97.2 %) and lower sequence similarity ( < 97.0 %) to all other species of the genus Azospirillum. According to DNA-DNA association, the relatedness values of strain CC-HIH038T with A. doebereinerae, A. thiophilum, A. rugosum and A. zeae were 51.8 %, 41.2 %, 56.5 % and 37.5 %, respectively. Strain CC-HIH038T was able to grow at 20-37 °C and pH 7.0-8.0. Strain CC-HIH038T gave positive amplification for dinitrogen reductase (nifH gene); the activity was recorded as 8.4 nmol ethylene h- 1. The predominant quinone system was ubiquinone Q-10 and the DNA G+C content was 68.8 mol%. The major fatty acids found in strain CC-HIH038T were C16 : 0, iso-C18 : 0, C16 : 0 3-OH, C14 : 0 3-OH/iso-C16 : 1 and C18 : 1ω7c/C18 : 1ω6c. Based on the distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence analysis, strain CC-HIH038T is considered to represent a novel species in the genus Azospirillum, for which the name Azospirillum agricola sp. nov. is proposed. The type strain is CC-HIH038T ( = BCRC 80909T = JCM 30827T).


Assuntos
Azospirillum/classificação , Fixação de Nitrogênio , Filogenia , Microbiologia do Solo , Azospirillum/genética , Azospirillum/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Nitrogênio , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan , Ubiquinona/química
12.
Int J Syst Evol Microbiol ; 63(Pt 7): 2618-2624, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23264502

RESUMO

A Gram-negative, facultative anaerobic, motile, spiral, straight-to-slightly curved rod-shaped and nitrogen-fixing strain, designated SgZ-5(T), was isolated from a microbial fuel cell (MFC) and was characterized by means of a polyphasic approach. Growth occurred with 0-1 % (w/v) NaCl (optimum 1 %) and at pH 5.5-8.5 (optimum pH 7.2) and at 25-37 °C (optimum 30 °C) in nutrient broth (NB). The strain had the ability to grow under anaerobic conditions via the oxidation of various organic compounds coupled to the reduction of anthraquione-2,6-disulfonate (AQDS). Chemotaxonomic characteristics (main ubiquinone Q-10, major fatty acid C18 : 1ω7c/C18 : 1ω6c and DNA G+C content 67.7 mol%) were similar to those of members of the genus Azospirillum. According to the results of phylogenetic analyses, strain SgZ-5(T) belonged to the genus Azospirillum within the family Rhodospirillaceae of the class Alphaproteobacteria, and was related most closely to the type strains of Azospirillum lipoferum, Azospirillum thiophilum and Azospirillum oryzae (98.0, 97.6 and 97.1 % 16S rRNA gene sequence similarity, respectively). DNA-DNA pairing studies showed that the unidentified organism displayed reassociation values of 36.7 ± 3.7, 24.1 ± 2.2 and 22.3 ± 2.4 % to the type strains of A. lipoferum, A. thiophilum and A. oryzae, respectively. Similarities between nifH gene sequences of strain SgZ-5(T) and members of the genus Azospirillum ranged from 94.0 to 97.0 %. A combination of phenotypic, chemotaxonomic, phylogenetic and genotypic data clearly indicated that strain SgZ-5(T) represents a novel species, for which the name Azospirillum humicireducens sp. nov. is proposed. The type strain is SgZ-5(T) ( = CCTCC AB 2012021(T) = KACC 16605(T)).


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Fixação de Nitrogênio , Filogenia , Azospirillum/classificação , Azospirillum/genética , Azospirillum/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Fosfolipídeos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/análise
13.
Microbiol Immunol ; 54(12): 717-25, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21091983

RESUMO

The endotoxic activities of lipopolysaccharides (LPS) isolated from different strains of rhizobia and rhizobacteria (Bradyrhizobium, Mesorhizobium, and Azospirillum) were compared to those of Salmonella enterica sv. Typhimurium LPS. The biological activity of all the examined preparations, measured as Limulus lysate gelation, production of tumor necrosis factor (TNF), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6), and nitrogen oxide (NO) induction in human myelomonocytic cells (line THP-1), was considerably lower than that of the reference enterobacterial endotoxin. Among the rhizobial lipopolysaccharides, the activities of Mesorhizobium huakuii and Azospirillum lipoferum LPSs were higher than those of the LPS preparations from five strains of Bradyrhizobium. The weak endotoxic activity of the examined preparations was correlated with differences in lipid A structure compared to Salmonella.


Assuntos
Alphaproteobacteria/patogenicidade , Azospirillum/patogenicidade , Bradyrhizobium/patogenicidade , Lipopolissacarídeos/toxicidade , Linhagem Celular , Citocinas/biossíntese , Humanos , Lipopolissacarídeos/isolamento & purificação , Óxido Nítrico/biossíntese
14.
J Gen Appl Microbiol ; 55(1): 1-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19282627

RESUMO

A Gram-negative bacterium designated ww 10(T) was isolated by plating dilutions from forest soil in Zhejiang province, China. Strain ww 10(T) was investigated by polyphasic taxonomic study including phenotypic and phylogenetic analysis. Cells of ww 10(T) were Gram-negative, strictly aerobic, motile with peritrichous flagella and rod-shaped. The strain grew optimally at 30-37 masculineC and pH 6.0-8.0. The major fatty acids were C(18:1)omega7C, cyclo-C(19:0) omega8C and C(16:0). The respiratory quinones contained a large amount of Q-10, a moderate component of Q-9 and a minor of Q-8. The G+C content of genomic DNA was about 67.3 mol%. Phylogenetic analysis revealed that strain ww 10(T) belongs to the phyletic cluster of genus Azospirillum and displayed 16S rRNA gene sequence similarity lower than 96.3% to the four closest described species of the genera Azospirillum and Roseomonas. Results of polyphasic taxonomic analysis showed that strain ww 10(T) represents a novel species in the genus Azospirillum, for which the name Azospirillum palatum sp. nov., is proposed. The type strain is ww 10(T) (=LMG 24444(T)=KCTC 13200(T)=CCTCC AB 207189(T)).


Assuntos
Azospirillum/classificação , Microbiologia do Solo , Árvores , Azospirillum/genética , Azospirillum/isolamento & purificação , Azospirillum/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Chaperonina 60/genética , China , DNA Bacteriano/análise , DNA Ribossômico/análise , Ácidos Graxos/análise , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
15.
Int J Syst Evol Microbiol ; 59(Pt 4): 761-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19329602

RESUMO

A polyphasic taxonomic study was performed on a pink-coloured unknown bacterium isolated from discarded road tar. Comparative analysis of the 16S rRNA gene sequence demonstrated that the isolate belongs phylogenetically to the genus Azospirillum with Azospirillum lipoferum, A. melinis and A. rugosum as its closest phylogenetic relatives (96.7, 96.6 and 96.6 % similarity to the respective type strains). The generic assignment was confirmed on the basis of chemotaxonomic data, which revealed a fatty acid profile characteristic for the genus Azospirillum, consisting of straight-chain saturated and unsaturated fatty acids, with C(18 : 1)omega7c as the major unsaturated non-hydroxylated fatty acid, and C(16 : 0) 3-OH as the major hydroxylated fatty acid, and a ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone. On the basis of both the phenotypic and molecular genetic evidence, it is proposed that the unknown isolate should be classified within a novel species of the genus Azospirillum, for which the name Azospirillum picis sp. nov. is proposed. The type strain is IMMIB TAR-3(T) (=CCUG 55431(T) =DSM 19922(T)).


Assuntos
Azospirillum/classificação , Azospirillum/isolamento & purificação , Microbiologia Ambiental , Azospirillum/química , Azospirillum/genética , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
16.
An. acad. bras. ciênc ; 80(4): 749-761, Dec. 2008. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-497117

RESUMO

This work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (Zinc, Cadmium and NaCl tolerance in vitro, and protein profiles) and genotypically (16S rDNA sequencing), as compared to type strains of known diazotrophic species. Densities were evaluated by using NFb, Fam and JNFb media, commonly used for enrichment cultures of diazotrophic bacteria. Bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. Azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to Zn+2 and Cd+2, being Cd+2 more toxic than Zn+2. Among the most tolerant isolates (UFLA 1S, 1R, S181, S34 and S22), some (1R, S34 and S22) were more tolerant to heavy metals than rhizobia from tropical and temperate soils. The majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g L-1 NaCl. Five isolates exhibited high dissimilarity in protein profiles, and the 16S rDNA sequence analysis of two of them revealed new sequences for Azospirillum.


Objetivou-se avaliar a densidade de populações de bactérias diazotróficas associativas em amostras de solos e de raízes de gramíneas oriundas de sítios contaminados com metais pesados, e caracterizar isolados destas populações através da análise fenotípica (tolerância aos metais pesados zinco e cádmio e à NaCl in vitro, perfis protéicos), e genotípica (seqüenciamento de 16S rDNA), comparados às estirpes tipo das mesmas espécies. As densidades foram avaliadas nos meios NFb, Fam e LGI, comumente utilizados para culturas de enriquecimento de populações de bactérias diazotróficas associativas. As densidades encontradas em amostras de solo e raiz de sítios contaminados foram semelhantes àquelas relatadas na literatura para solos agrícolas. Isolados de Azospirillum spp. de solos contaminados e estirpes tipo oriundas de solos não contaminados variaram substancialmente com relação à tolerância a Zn+2 e Cd+2, sendo que Cd+2 mais tóxico que Zn+2. Dentre os isolados mais tolerantes (UFLA 1S, 1R, S181, S34, e S22), alguns(1R, S34 e S22) foram mais tolerantes a metais pesados que rizóbios isolados de solos de áreas tropicais e temperadas. A maioria dos isolados mais tolerantes a metais pesados também foi tolerante ao estresse salino, o que foi indicado por seu crescimento em meio sólido suplementado com 30 g L-1 de NaCl in vitro. Cinco isolados apresentaram alta dissimilaridade em perfis protéicos e o seqüenciamento do gene 16S rDNA em dois deles revelou que apresentam novas seqüências de Azospirillum.


Assuntos
Azospirillum/efeitos dos fármacos , Burkholderia/efeitos dos fármacos , Herbaspirillum/efeitos dos fármacos , Metais Pesados/toxicidade , Raízes de Plantas/microbiologia , Poaceae/microbiologia , Microbiologia do Solo , Azospirillum/genética , Azospirillum/crescimento & desenvolvimento , Burkholderia/genética , Burkholderia/crescimento & desenvolvimento , Contagem de Colônia Microbiana , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Genótipo , Herbaspirillum/genética , Herbaspirillum/crescimento & desenvolvimento , Metais Pesados/análise , Fenótipo , /genética
17.
Univ. sci ; 13(2): 162-170, jul.-sep. 2008. tab, graf
Artigo em Espanhol | LILACS | ID: lil-582128

RESUMO

Se realizó la inoculación de Azospirillum brasilense inmovilizado en microperlas de alginato y de los hongos Glomus manihotis y Glomus occultum en semillas de Gmelina arborea en tres grados de madurez. Las semillas inoculadas se sembraron en suelo y en turba compactada. Cuarenta y un días después de la siembra se determinó el efecto de los sistemas de siembra y de los microorganismos sobre la germinación. Cuarenta y siete días después del transplante a bolsa se determinaron las variables de micorrización y altura de las plantas. El sustrato de siembra (p<0.01) y la inoculación de A. brasilense (p<0.01) influyeron en la germinación de las semillas de G. arborea. Se presentó correlación positiva entre micorrización y la altura de las plantas durante el establecimiento en vivero (0.61 p=0.03). Además se presentó un efecto sinérgico de los microorganismos sobre la micorrización.


Seeds of Gmelina arborea at three different maturity degrees were inoculated with Glomus manihotis,Glomus occultum and Azospirillum brasilense immobilized in alginate microbeads. Inoculated seeds were sown in two different growing systems: soil and compacted- peat-Jiffy®. Forty-one days after sowing (das), the effects of growing system and microorganism application on seed germination were determined. Forty-seven das, mycorrhization percentages and plant height were evaluated. Results showed that the growing system and the inoculation of A. brasilense have a significant effect (p<0.01) on the germination of G. arborea seeds. A positive correlation between mycorrhization and plantheight was found during the initial stage of establishment in greenhouse conditions (0.61 p=0.03). In addition, there is a synergic effect of both types of microorganisms on mycorrhization.


Assuntos
Azospirillum , Germinação
18.
Int J Syst Evol Microbiol ; 58(Pt 4): 959-63, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18398202

RESUMO

The taxonomic status of a light-orange-coloured bacterial isolate from an oil-contaminated soil sample was characterized by using a polyphasic taxonomic approach. Comparative analysis of 16S rRNA gene sequences demonstrated that the isolate belonged phylogenetically to the genus Azospirillum, with Azospirillum canadense, Azospirillum brasilense and Azospirillum doebereinerae as its closest phylogenetic relatives (97.3, 97.0 and 97.0 % similarity, respectively). DNA-DNA pairing studies showed that the unidentified organism displayed 25.0, 17.0 and 19.0 % relatedness to the type strains of A. brasilense, A. canadense and A. doebereinerae, respectively. The generic assignment was confirmed by chemotaxonomic data, which revealed a fatty acid profile that was characteristic of the genus Azospirillum, consisting of straight-chain saturated and unsaturated fatty acids with C18 : 1 omega 7c as the major fatty acid, and ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone. On the basis of both the phenotypic and molecular genetic evidence, it is proposed that the unknown isolate be classified as a representative of a novel species of the genus Azospirillum, for which the name Azospirillum rugosum sp. nov. is proposed. The type strain is IMMIB AFH-6T (=CCUG 53966T=DSM 19657T).


Assuntos
Azospirillum/classificação , Azospirillum/isolamento & purificação , Azospirillum/genética , Azospirillum/metabolismo , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Óleos Combustíveis , Genes Bacterianos , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo , Poluentes do Solo/metabolismo , Especificidade da Espécie , Terminologia como Assunto , Ubiquinona/metabolismo
19.
Int J Syst Evol Microbiol ; 57(Pt 12): 2805-2809, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18048728

RESUMO

Two free-living nitrogen-fixing bacterial strains, N6 and N7(T), were isolated from corn rhizosphere. A polyphasic taxonomic approach, including morphological characterization, Biolog analysis, DNA-DNA hybridization, and 16S rRNA, cpn60 and nifH gene sequence analysis, was taken to analyse the two strains. 16S rRNA gene sequence analysis indicated that strains N6 and N7(T) both belonged to the genus Azospirillum and were closely related to Azospirillum oryzae (98.7 and 98.8 % similarity, respectively) and Azospirillum lipoferum (97.5 and 97.6 % similarity, respectively). DNA-DNA hybridization of strains N6 and N7(T) showed reassociation values of 48 and 37 %, respectively, with A. oryzae and 43 % with A. lipoferum. Sequences of the nifH and cpn60 genes of both strains showed 99 and approximately 95 % similarity, respectively, with those of A. oryzae. Chemotaxonomic characteristics (Q-10 as quinone system, 18 : 1omega7c as major fatty acid) and G+C content of the DNA (67.6 mol%) were also similar to those of members of the genus Azospirillum. Gene sequences and Biolog and fatty acid analysis showed that strains N6 and N7(T) differed from the closely related species A. lipoferum and A. oryzae. On the basis of these results, it is proposed that these nitrogen-fixing strains represent a novel species. The name Azospirillum zeae sp. nov. is suggested, with N7(T) (=NCCB 100147(T)=LMG 23989(T)) as the type strain.


Assuntos
Azospirillum/classificação , Azospirillum/isolamento & purificação , Raízes de Plantas/microbiologia , Microbiologia do Solo , Zea mays/microbiologia , Azospirillum/química , Azospirillum/genética , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Chaperonina 60/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Genes de RNAr , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Fixação de Nitrogênio/fisiologia , Hibridização de Ácido Nucleico , Oxirredutases/genética , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
20.
Rev. colomb. biotecnol ; 9(2): 6-4, dic. 2007. tab
Artigo em Espanhol | LILACS | ID: lil-480278

RESUMO

Se aislaron bacterias diazotróficas de los géneros Azotobacter sp y Azospirrillum sp a partir de la rizosfera de cultivos de plátano, pastos, maíz y de rastrojos (zonas sin cultivar) en el municipio de San Carlos (Valle del Sinú medio en el departamento de Córdoba, Colombia). Las poblaciones microbianas se identificaron mediante pruebas bioquímicas y observación macroscópica y microscópica con tinción de Gram en diferentes medios de cultivo: a) Burk´s, Asbhy y Jensen´s, (género Azotobacter sp), y b) Burk´s, nfb y rojo congo (género Azospirillum sp). El objetivo del presente trabajo fue determinar la producción del ión amonio a partir de los géneros bacterianos aislados;la cuantificación del ión amonio fue llevada a cabo por el método colorimétrico de Berthelot (fenol-hipoclorito) empleando un espectrofotómetro Perkin-Elmer Lamba 11 uv-Vis; la técnica fue modificada y estandarizada de acuerdo con las condiciones del equipo. Como resultado seobtuvieron 14 aislados que produjeron concentraciones de 0,9 hasta 5,2 mg/l, siendo los más destacados para el género Azotobacter sp, A16PG y A26M1P (5,1545 y 5,1743 mg/l de amonio, respectivamente), y para el género Azospirrillum spp, A5M1G (4,6741 mg/l de amonio). La fijación biológica del nitrógeno (fbn) por bacterias diazotróficas ha contribuido a incrementar el rendimiento en las cosechas, reduciendo la necesidad de fertilizantes nitrogenados y la emisión de gases tóxicos como el N2O, obteniendo beneficios económicos y ambientales en las granjas.


Assuntos
Azospirillum/metabolismo , Azotobacter/metabolismo
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