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1.
Arch Microbiol ; 203(3): 1131-1148, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33206216

RESUMEN

This research aims to isolate and identify Zn- and Cd-tolerant endophytic bacteria from Murdannia spectabilis, identify their properties with and without Zn and Cd stress, and to investigate the effect of bacterial inoculation in an in vitro system. Twenty-four isolates could survive on trypticase soya agar (TSA) supplemented with Zn (250-500 mg L-1) and/or Cd (20-50 mg L-1) that belonged to the genera Bacillus, Pantoea, Microbacterium, Curtobacterium, Chryseobacterium, Cupriavidus, Siphonobacter, and Pseudomonas. Each strain had different indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and siderophore production, nitrogen fixation, phosphate solubilization, and lignocellulosic enzyme characteristics. Cupriavidus plantarum MDR5 and Chryseobacterium sp. MDR7 were selected for inoculation into plantlets that were already occupied by Curtobacterium sp. TMIL due to them have a high tolerance for Zn and Cd while showing no pathogenicity. As determined via an in vitro system, Cupriavidus plantarum MDR5 remained in the plants to a greater extent than Chryseobacterium sp. MDR7, while Curtobacterium sp. TMIL was the dominant species. The Zn plus Cd treatment supported the persistence of Cupriavidus plantarum MDR5. Dual and mixed cultivation showed no antagonistic effects between the endophytes. Although the plant growth and Zn/Cd accumulation were not significantly affected by the Zn-/Cd-tolerant endophytes, the inoculation did not weaken the plants. Therefore, Cupriavidus plantarum MDR5 could be applied in a bioaugmentation process.


Asunto(s)
Actinomycetales/efectos de los fármacos , Actinomycetales/fisiología , Cadmio/farmacología , Commelinaceae/microbiología , Cupriavidus/efectos de los fármacos , Cupriavidus/fisiología , Zinc/farmacología , Antibiosis , Biodegradación Ambiental , Liasas de Carbono-Carbono/metabolismo , Endófitos/clasificación , Endófitos/aislamiento & purificación , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/microbiología , Sideróforos/metabolismo , Contaminantes del Suelo/farmacología
2.
J Appl Microbiol ; 127(4): 1057-1068, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31260173

RESUMEN

AIMS: To evaluate hexavalent chromium (Cr (VI)) reduction potential of indigenous isolate M5, under growing and nongrowing conditions. METHODS AND RESULTS: Microbacterium sp. M5 was isolated from soil samples collected from a common effluent treatment plant, after enrichment of indigenous microbial diversity in the presence of 200 mg l-1 of Cr (VI). The isolate achieved complete reduction of 400 mg l-1 Cr (VI) supplement to Luria Bertani medium having initial pH of 9·0 after 48 h incubation. Furthermore, the reduction potential of resting and surfactant treated cell membrane compromised cells of M5 was evaluated. The control and biosurfactant treated cells achieved 22·71 ± 0·5% and 40·56 ± 0·5% reduction of 50 mg l-1 Cr (VI) in Tris-HCl buffer, under resting cells conditions. To the best of our knowledge, this is the first report where cells with compromised cell membrane obtained after exposure to biosurfactant have been evaluated for Cr (VI) reduction. CONCLUSION: The Cr (VI) reduction potential of Microbacterium sp. M5 could be effectively exploited for treatment of chromium-rich effluents, under nongrowing conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: The isolate M5 could be a potential inoculum for effluent treatment plants as it is able to support Cr (VI) reduction under wide range of pH, salinity and in the presence of different metal ions.


Asunto(s)
Actinomycetales/crecimiento & desarrollo , Actinomycetales/metabolismo , Cromo/metabolismo , Contaminantes del Suelo/metabolismo , Purificación del Agua/métodos , Actinomycetales/efectos de los fármacos , Biodegradación Ambiental/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Oxidación-Reducción , Salinidad , Aguas del Alcantarillado/microbiología , Tensoactivos/farmacología
3.
Acta Biochim Biophys Sin (Shanghai) ; 50(8): 757-765, 2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-30007316

RESUMEN

Amycolatopsis mediterranei U32 is an important industrial strain for the production of rifamycin SV. Rifampicin, a derivative of rifamycin SV, is commonly used to treat mycobacterial infections. Although phosphate has long been known to affect rifamycin biosynthesis, phosphate transport, metabolism, and regulation are poorly understood in A. mediterranei. In this study, the functional phosphate transport system pstSCAB was isolated by RNA sequencing and inactivated by insertion mutation in A. mediterranei U32. The mycelium morphology changed from a filamentous shape in the wild-type and pstS1+ strains to irregular swollen shape at the end of filamentous in the ΔpstS1 strain. RT-PCR assay revealed that pstSCAB genes are co-transcribed as a polycistronic messenger. The pstSCAB transcription was significantly activated by nitrate supplementation and positively regulated by GlnR which is a global regulator of nitrogen metabolism in actinomycetes. At the same time, the yield of rifamycin SV decreased after mutation (ΔpstS1) compared with wild-type U32, which indicated a strong connection among phosphate metabolism, nitrogen metabolism, and rifamycin production in actinomycetes.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Actinomycetales/genética , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Activación Transcripcional , Transportadoras de Casetes de Unión a ATP/metabolismo , Actinomycetales/efectos de los fármacos , Actinomycetales/metabolismo , Proteínas Bacterianas/metabolismo , Mutación , Nitratos/metabolismo , Nitratos/farmacología , Nitrógeno/metabolismo , Operón , Fosfatos/metabolismo , Rifamicinas/biosíntesis
4.
Dokl Biol Sci ; 479(1): 67-69, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29790031

RESUMEN

The impact of selenium biocomposites obtained from the medicinal macrobasidiomycetes Ganoderma lucidum, Grifola umbellata, Laetiporus sulphureus, Lentinula edodes, and Pleurotus ostreatus on the viability and biofilm formation capability of the phytopathogenic Gram-positive bacterium Clavibacter michiganensis ssp. sepedonicus (Spieck. et Kotth.) (Cms) was studied. Impairment of bacterial cell viability resulting from their incubation with biocomposites was shown. The decisive role of the composites' selenium component on the biological activity under question was established. The dependence of antimicrobial effect of the selenium-containing specimen on the mushroom systematic position was revealed. The maximal activity was found for the biocomposites based on the extracellular metabolites of L. edodes and G. lucidum. When the biopolymer specimen of fungal origin was added to bacterial suspension, the Cms capability of forming biofilms was found to be distinctly dependent of the biocomposite type, and it was substantially reduced in a number of cases.


Asunto(s)
Actinomycetales/efectos de los fármacos , Antibacterianos/farmacología , Basidiomycota/química , Productos Biológicos/farmacología , Selenio/análisis , Actinomycetales/patogenicidad , Antibacterianos/química , Basidiomycota/clasificación , Productos Biológicos/química , Solanum tuberosum/microbiología
5.
Microb Cell Fact ; 16(1): 120, 2017 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-28709434

RESUMEN

BACKGROUND: Nonomuraea dietziae is a promising microorganism to mediate the region-specific monooxygenation reaction of cyclosporine A (CsA). The main product [(4'-OH)MeLeu]4-CsA possesses high anti-HIV/HCV and hair growth-stimulating activities while avoiding the immunosuppressive effect of CsA. However, the low conversion efficiency restricts the clinical application. In this study, the production of [(4'-OH)MeLeu]4-CsA was greatly improved by 55.6% from 182.8 to 284.4 mg/L when supplementing soybean oil into the production medium, which represented the highest production of [(4'-OH)MeLeu]4-CsA so far. RESULTS: To investigate the effect of soybean oil on CsA conversion, some other plant oils (corn oil and peanut oil) and the major hydrolysates of soybean oil were fed into the production medium, respectively. The results demonstrated that the plant oils, rather than the hydrolysates, could significantly improve the [(4'-OH)MeLeu]4-CsA production, suggesting that soybean oil might not play its role in the lipid metabolic pathway. To further unveil the mechanism of [(4'-OH)MeLeu]4-CsA overproduction under the soybean oil condition, a proteomic analysis based on the two-dimensional gel electrophoresis coupled with MALDI TOF/TOF mass spectrometry was implemented. The results showed that central carbon metabolism, genetic information processing and energy metabolism were significantly up-regulated under the soybean oil condition. Moreover, the gas chromatography-mass spectrometry-based metabolomic analysis indicated that soybean oil had a great effect on amino acid metabolism and tricarboxylic acid cycle. In addition, the transcription levels of cytochrome P450 hydroxylase (CYP) genes for CsA conversion were determined by RT-qPCR and the results showed that most of the CYP genes were up-regulated under the soybean oil condition. CONCLUSIONS: These findings indicate that soybean oil could strengthen the primary metabolism and the CYP system to enhance the mycelium growth and the monooxygenation reaction, respectively, and it will be a guidance for the further metabolic engineering of this strain.


Asunto(s)
Actinomycetales/genética , Actinomycetales/metabolismo , Ciclosporina/metabolismo , Metabolómica , Proteómica , Aceite de Soja/metabolismo , Actinomycetales/efectos de los fármacos , Aminoácidos/metabolismo , Antivirales/aislamiento & purificación , Antivirales/metabolismo , Ciclo del Ácido Cítrico , Ciclosporinas/aislamiento & purificación , Ciclosporinas/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Electroforesis en Gel Bidimensional , Cromatografía de Gases y Espectrometría de Masas , Inmunosupresores/metabolismo , Metabolismo de los Lípidos , Ingeniería Metabólica , Redes y Vías Metabólicas , Aceites de Plantas/farmacología , Aceite de Soja/farmacología
6.
Environ Sci Pollut Res Int ; 22(6): 4425-33, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25307859

RESUMEN

Enzyme activity and microbial population in soils have important roles in keeping soil fertility. ZJ0273 is a novel pyrimidynyloxybenzoic-based herbicide, which was recently developed in China. The effect of ZJ0273 on soil enzyme activity and microbial population in two different soils was investigated in this study for the first time. The protease activity was significantly inhibited by ZJ0273 and this inhibiting effect gradually weakened after 60-day incubation. The results also showed that ZJ0273 had different stimulating effects on the activities of dehydrogenase, urease, and catalase. Dehydrogenase was consistently stimulated by all the applied concentrations of ZJ0273. The stimulating effect on urease weakened after 60-day incubation. Catalase activity was subject to variations during the period of the experiments. The results of microbial population showed that the number of bacteria and actinomycetes increased in ZJ0273-treated soil compared with the control after 20 days of incubation, while fungal number decreased after only 10 days of incubation in soils. DT50 (half-life value) and k (degradation rate constant) of ZJ0273 in S1 (marine-fluvigenic yellow loamy soil) and S2 (Huangshi soil) were found 69.31 and 49.50 days and 0.010 and 0.014 day(-1), respectively.


Asunto(s)
Benzoatos/efectos adversos , Herbicidas/efectos adversos , Microbiología del Suelo , Contaminantes del Suelo/efectos adversos , Suelo/química , Actinomycetales/efectos de los fármacos , Actinomycetales/metabolismo , Benzoatos/química , Biodegradación Ambiental , Catalasa/metabolismo , China , Hongos/efectos de los fármacos , Hongos/metabolismo , Semivida , Cinética , Estructura Molecular , Oxidorreductasas/metabolismo , Péptido Hidrolasas/metabolismo , Espectrofotometría , Factores de Tiempo , Ureasa/metabolismo
7.
PLoS One ; 9(4): e94329, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24714388

RESUMEN

Bacterial ring rot of potato is one of the most serious potato plant and tuber diseases. Laminaria japonica extract was investigated for its antimicrobial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causative agent of bacterial ring rot of potato. The results showed that the optimum extraction conditions of antimicrobial substances from L. japonica were an extraction temperature of 80°C, an extraction time of 12 h, and a solid to liquid ratio of 1∶25. Active compounds of L. japonica were isolated by solvent partition, thin layer chromatography (TLC) and column chromatography. All nineteen fractionations had antimicrobial activities against C. michiganense subsp. sepedonicum, while Fractionation three (Fr.3) had the highest (P<0.05) antimicrobial activity. Chemical composition analysis identified a total of 26 components in Fr.3. The main constituents of Fr.3 were alkanes (80.97%), esters (5.24%), acids (4.87%) and alcohols (2.21%). Antimicrobial activity of Fr.3 against C. michiganense subsp. sepedonicum could be attributed to its ability to damage the cell wall and cell membrane, induce the production of reactive oxygen species (ROS), increase cytosolic Ca2+ concentration, inhibit the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle, inhibit protein and nucleic acid synthesis, and disrupt the normal cycle of DNA replication. These findings indicate that L. japonica extracts have potential for inhibiting C. michiganense subsp. sepedonicum.


Asunto(s)
Actinomycetales/efectos de los fármacos , Laminaria/química , Extractos Vegetales/farmacología , Actinomycetales/metabolismo , Actinomycetales/ultraestructura , Antibacterianos/farmacología , Proteínas Bacterianas/metabolismo , Calcio/metabolismo , Catalasa/metabolismo , Membrana Celular/efectos de los fármacos , Pared Celular/efectos de los fármacos , Fraccionamiento Químico , Citosol/metabolismo , Replicación del ADN/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo
8.
Biochimie ; 99: 63-70, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24275143

RESUMEN

A novel plant hairpin-like defense polypeptide named EcAMP3 was isolated from latent barnyard grass (Echinochloa crusgalli L.) seeds. The native peptide and its recombinant analogue were characterized. EcAMP3 displays antifungal and antibacterial activity in vitro. The gene family encoding EcAMPs precursor protein was also characterized; the genes and pseudogenes of this family show 97-100% homology. Every member of EcAMPs precursor family contains seven identical cysteine motifs: C1XXXC2(11-13)C3XXXC4. One of those motifs corresponds to the isolated peptide. EcAMP3 is the first member of the plant hairpin-like peptide family that inhibits the growth of phytopathogenic bacteria. Obtained results can explain the nature of the complex resistance of barnyard grass to a variety of pathogenic microorganisms.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Echinochloa/química , Proteínas de Plantas/farmacología , Semillas/química , Actinomycetales/efectos de los fármacos , Secuencia de Aminoácidos , Antibacterianos/química , Antifúngicos/química , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/genética , Aspergillus niger/efectos de los fármacos , Fusarium/efectos de los fármacos , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Pectobacterium carotovorum/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Extractos Vegetales/química , Extractos Vegetales/genética , Extractos Vegetales/farmacología , Inmunidad de la Planta , Proteínas de Plantas/química , Proteínas de Plantas/genética , Estructura Secundaria de Proteína , Pseudomonas syringae/efectos de los fármacos , Homología de Secuencia de Aminoácido
9.
Biodegradation ; 25(3): 425-35, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24166159

RESUMEN

Mining often leads to nitrate and metal contamination of groundwater and water bodies. Denitrification of acidic water was investigated in two up-flow fluidized-bed reactors (FBR) and using batch assays. Bacterial communities were enriched on ethanol plus nitrate in the FBRs. Initially, the effects of temperature, low-pH and ethanol/nitrate on denitrification were revealed. Batch assays showed that pH 4.8 was inhibitory to denitrification, whereas FBR characteristics permitted denitrification even at feed pH of 2.5 and at 7-8 °C. Nitrate and ethanol were removed and the feed pH was neutralized, provided that ethanol was supplied in excess to nitrate. Subsequently, Fe(II) and Cu impact on denitrification was investigated within batch tests at pH 7. Iron supplementation up to 100 mg/L resulted in iron oxidation and soluble concentrations ranging from 0.4 to 1.6 mg/L that stimulated denitrification. On the contrary, 0.7 mg/L of soluble Cu significantly slowed denitrification down resulting in about 45 % of inhibition in the first 8 h. Polymerase chain reaction-denaturant gradient gel electrophoresis demonstrated the co-existence of different denitrifying microbial consortia in FBRs. Dechloromonas denitrificans and Hydrogenophaga caeni were present in both FBRs and mainly responsible for nitrate reduction.


Asunto(s)
Actinomycetales/metabolismo , Comamonadaceae/metabolismo , Minería , Nitratos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Actinomycetales/efectos de los fármacos , Técnicas de Cultivo Celular por Lotes , Biodegradación Ambiental , Reactores Biológicos , Comamonadaceae/efectos de los fármacos , Cobre/farmacología , Desnitrificación , Compuestos Ferrosos/farmacología , Humanos , Concentración de Iones de Hidrógeno , Cinética , Oxidación-Reducción , Temperatura
10.
PLoS One ; 8(7): e68480, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23861908

RESUMEN

The Polygonum orientale L. extracts were investigated for antibacterial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causal agent of a serious disease called bacterial ring rot of potato. The results showed that the leaf extracts of P. orientale had significantly (p<0.05) greater antibacterial activity against C. michiganense subsp. sepedonicum than root, stem, flower extracts in vitro. According to the results of single factor experiments and L(27)3(13) orthogonal experiments, optimum extraction conditions were A1B3C1, extraction time 6 h, temperature 80°C, solid to liquid ratio 1∶10 (g:mL). The highest (p<0.05) antibacterial activity was observed when pH was 5, excluding the effect of control. The extracts were stable under ultraviolet (UV). In vivo analysis revealed that 50 mg/mL of P. orientale leaf extracts was effective in controlling decay. Under field conditions, 50 mg/mL of P. orientale leaf extracts also improved growth parameters (whole plant length, shoot length, root length, plant fresh weight, shoot fresh weight, root fresh weight, dry weight, and number of leaves), in the 2010 and 2011 two growing seasons. Further solvent partition assays showed that the most active compounds were in the petroleum ether fractionation. Transmission electron microscopy (TEM) showed drastic ultrastructural changes caused by petroleum ether fractionation, including bacterial deformation, electron-dense particles, formation of vacuoles and lack of cytoplasmic materials. These results indicated that P. orientale extracts have strong antibacterial activity against C. michiganense subsp. sepedonicum and a promising effect in control of bacterial ring rot of potato disease.


Asunto(s)
Actinomycetales/efectos de los fármacos , Antibacterianos/farmacología , Enfermedades de las Plantas/terapia , Extractos Vegetales/química , Reguladores del Crecimiento de las Plantas/farmacología , Polygonum/química , Solanum tuberosum/efectos de los fármacos , Actinomycetales/crecimiento & desarrollo , Antibacterianos/aislamiento & purificación , Fraccionamiento Químico , Flores/química , Pruebas de Sensibilidad Microbiana , Enfermedades de las Plantas/microbiología , Extractos Vegetales/aislamiento & purificación , Reguladores del Crecimiento de las Plantas/aislamiento & purificación , Hojas de la Planta/química , Raíces de Plantas/química , Tallos de la Planta/química , Solanum tuberosum/microbiología
11.
Appl Environ Microbiol ; 79(18): 5721-7, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23851100

RESUMEN

It has previously been shown that the tomato pathogen Clavibacter michiganensis subsp. michiganensis secretes a 14-kDa protein, C. michiganensis subsp. michiganensis AMP-I (CmmAMP-I), that inhibits growth of Clavibacter michiganensis subsp. sepedonicus, the causal agent of bacterial ring rot of potato. Using sequences obtained from tryptic fragments, we have identified the gene encoding CmmAMP-I and we have recombinantly produced the protein with an N-terminal intein tag. The gene sequence showed that CmmAMP-I contains a typical N-terminal signal peptide for Sec-dependent secretion. The recombinant protein was highly active, with 50% growth inhibition (IC50) of approximately 10 pmol, but was not toxic to potato leaves or tubers. CmmAMP-I does not resemble any known protein and thus represents a completely new type of bacteriocin. Due to its high antimicrobial activity and its very narrow inhibitory spectrum, CmmAMP-1 may be of interest in combating potato ring rot disease.


Asunto(s)
Actinomycetales/efectos de los fármacos , Actinomycetales/metabolismo , Antiinfecciosos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Actinomycetales/genética , Antiinfecciosos/toxicidad , Proteínas Bacterianas/toxicidad , Concentración 50 Inhibidora , Solanum lycopersicum , Pruebas de Sensibilidad Microbiana , Hojas de la Planta/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/toxicidad , Solanum tuberosum/efectos de los fármacos
12.
Biochemistry (Mosc) ; 74(3): 260-7, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19364319

RESUMEN

The possibility to use agrobacterial transformation of leaf discs to produce resistance to bacterial infections in tobacco and potato plants by introduction of a single gene encoding the serine proteinase inhibitor BWI-1a (ISP) from buckwheat seeds is shown. All studied PCR-positive transgenic plants exhibited antibacterial activity in biotests. It was shown that the presence of just a single gene of serine proteinase inhibitor provides sufficient protection at least against two bacterial phytopathogens, Pseudomonas syringae pv. tomato and Clavibacter michiganensis sbsp. michiganensis. The biotest including tobacco plant infection by the white wings butterfly in the green house has also demonstrated the existence of protective effect in transgenic tobacco plants. Significant genotypic variations in the protection efficiency were found between members of different genera of the same family (potato and tobacco) as well as between different lines of the same species. Northern blot analysis of four transgenic potato lines and three tobacco lines transformed by a vector plasmid containing the ISP gene of serine proteinases BWI-1a from buckwheat seeds has shown the presence of the expected size mRNA transcript.


Asunto(s)
Fagopyrum/genética , Nicotiana/genética , Proteínas de Plantas/genética , Semillas/genética , Solanum tuberosum/genética , Actinomycetales/efectos de los fármacos , Actinomycetales/crecimiento & desarrollo , Animales , Mariposas Diurnas/crecimiento & desarrollo , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Hemípteros/crecimiento & desarrollo , Inmunidad Innata/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Extractos Vegetales/farmacología , Plantas Modificadas Genéticamente , Pseudomonas syringae/efectos de los fármacos , Pseudomonas syringae/crecimiento & desarrollo , Solanum tuberosum/microbiología , Solanum tuberosum/parasitología , Nicotiana/microbiología , Nicotiana/parasitología
13.
Mikrobiologiia ; 77(5): 581-9, 2008.
Artículo en Ruso | MEDLINE | ID: mdl-19004337

RESUMEN

A number of halotolerant and halophilic bacterial strains were isolated from the Romashkinskoe oil field (Tatarstan) stratal waters having a salinity of up to 100 g/l. The isolation of pure cultures involved biofilm reconstitution on M9 medium with paraffins. The associations obtained were dispersed and reinoculated onto solid media that contained either peptone and yeast extract (PY) or paraffins. It was shown that such associations included both oil-oxidizing bacteria and accompanying chemoheterotrophic bacteria incapable of oil oxidation. The pure cultures that were isolated were used for creating binary biofilms. In these biofilms, interactions between halophilic and nonhalophilic bacteria under hypo- and hyperosmotic shocks were investigated. We conducted a detailed study of a biofilm obtained from an oil-oxidizing halotolerant species (with an upper growth limit of 10-12% NaCl) identified as Dietzia sp. and an extremely halophilic gram-negative bacterium (growing within the 5-20% NaCl concentration range) of the genus Chromohalobacter that did not oxidize paraffins. If these microorganisms were grown in a mixed suspension (planktonic) culture that was not supplemented with an additional amount of NaCl, no viable cells of the halophilic microorganism were detected after reinoculation. In contrast, only halophilic cells were detected at a NaCl concentration of 15%. Thus, no mutual protective influence of the microorganisms manifested itself in suspension culture, either under hypo- or under hyperosmotic shock. Neither could the halophile cells be detected after reinoculating a biofilm obtained on a peptone medium without addition of NaCl. However, biofilms produced at a NaCl concentration of 15% contained approximately equal numbers of cells of the halophilic and halotolerant organisms. Thus, the halophile in biofilms sustaining a hyperosmotic shock exerts a protective influence on the halotolerant microorganism. Preliminary data suggest that this effect is due to release by the halophile of osmoprotective substances (ectoine and glutamate), which are taken up by the halotolerant species. Such substances are diluted by a large medium volume in suspension cultures, whereas, in biofilms, their diffusion into the medium is apparently hampered by their interaction with the intercellular polymer matrix.


Asunto(s)
Actinomycetales/fisiología , Biopelículas , Petróleo/microbiología , Salinidad , Cloruro de Sodio/farmacología , Microbiología del Agua , Actinomycetales/clasificación , Actinomycetales/efectos de los fármacos , Actinomycetales/crecimiento & desarrollo , Aminoácidos Diaminos/metabolismo , Medios de Cultivo , Halomonadaceae/clasificación , Halomonadaceae/efectos de los fármacos , Halomonadaceae/aislamiento & purificación , Halomonadaceae/fisiología , Presión Osmótica , Oxidación-Reducción , Parafina/metabolismo , Petróleo/metabolismo , Filogenia , Simbiosis
14.
J Appl Microbiol ; 100(2): 390-7, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16430516

RESUMEN

AIMS: To study the effect of sulfur-containing amino acids (L-cysteine, L-cystine, L-methionine and DL-ethionine) on the production of dithiolopyrrolone antibiotics by Saccharothrix algeriensis NRRL B-24137. METHODS AND RESULTS: The production levels of dithiolopyrrolones were investigated by using high performance liquid chromatography in a chemically semi-synthetic medium. The production of the studied antibiotics depends upon the nature, concentration and the time of addition of these sources in the culture medium. Both cysteine and cystine favoured the specific productions of dithiolopyrrolones; iso-butyryl-pyrrothine (ISP) by cysteine, however butanoyl-pyrrothine, senecioyl-pyrrothine and tigloyl-pyrrothine by cystine, when added initially to the culture medium. The maximum specific productions of dithiolopyrrolones were observed in the presence of 5 mmol l(-1) cystine for thiolutin, 5 mmol l(-1) cysteine for ISP, and 10 mmol l(-1) cystine for others studied dithiolopyrrolones as shown in Fig. 3. The production of these antibiotics was decreased when the concentrations of cysteine and cystine were in excess. All dithiolopyrrolone specific productions were strongly inhibited by addition of methionine and ethionine, without inhibition of mycelial growth. CONCLUSIONS: Among all studied amino acids, cystine and cysteine can be used as supplements for improvement the production of dithiolopyrrolone antibiotics by S. algeriensis NRRL B-24137. SIGNIFICANCE AND IMPACT OF THE STUDY: Dithiolopyrrolone antibiotics have many important applications for employing them as medicaments, particularly in the treatment of human and animal cancers. In the present work, the influence of containing-sulfur amino acids on dithiolopyrrolone antibiotic productions was studied. The obtained results can be employed for the optimization of the culture medium for the dithiolopyrrolone productions in higher quantities.


Asunto(s)
Actinomycetales/metabolismo , Aminoácidos Sulfúricos/farmacología , Antibacterianos/biosíntesis , Pirrolidinonas/metabolismo , Actinomycetales/efectos de los fármacos , Actinomycetales/crecimiento & desarrollo , Compuestos Bicíclicos Heterocíclicos con Puentes/metabolismo , Medios de Cultivo , Cisteína/farmacología , Cistina/farmacología , Relación Dosis-Respuesta a Droga , Etionina/farmacología , Fermentación , Concentración de Iones de Hidrógeno , Metionina/farmacología
15.
Biosci Biotechnol Biochem ; 67(8): 1636-42, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12951494

RESUMEN

Novel antimicrobial peptides (AMP), designated Fa-AMP1 and Fa-AMP2, were purified from the seeds of buckwheat (Fagopyrum esculentum Moench.) by gel filtration on Sephadex G75, ion-exchange HPLC on SP COSMOGEL, and reverse-phase HPLC. They were basic peptides having isoelectric points of over 10. Fa-AMP1 and Fa-AMP2 had molecular masses of 3,879 Da and 3,906 Da on MALDI-TOF MS analysis, and their extinction coefficients in 1% aqueous solutions at 280 nm were 42.8 and 38.9, respectively. Half of all amino acid residues of Fa-AMP1 and Fa-AMP2 were cysteine and glycine, and they had continuous sequences of cysteine and glycine. The concentrations of peptides required for 50% inhibition (IC50) of the growth of plant pathogenic fungi, and Gram-positive and -negative bacteria were 11 to 36 microg/ml. The structural and antimicrobial characteristics of Fa-AMPs indicated that they are a novel type of antimicrobial peptides belonging to a plant defensin family.


Asunto(s)
Defensinas/química , Defensinas/farmacología , Fagopyrum/química , Proteínas de Plantas/química , Proteínas de Plantas/farmacología , Actinomycetales/efectos de los fármacos , Secuencia de Aminoácidos , Aminoácidos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Defensinas/genética , Defensinas/aislamiento & purificación , Fusarium/efectos de los fármacos , Geotrichum/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Datos de Secuencia Molecular , Peso Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/aislamiento & purificación , Semillas/química , Alineación de Secuencia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
17.
Biotechnol Lett ; 25(1): 73-7, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12882310

RESUMEN

Ethanol, added as a de-emulsifier to separate oil and biocatalyst (or bacterial cells) from a three-phase (oil/biocatalyst/aqueous phase) emulsion, formed in diesel biodesulfurization employing Gordonia nitida, improved oil recovery by centrifugation from about 50% in its absence to almost 100% at 3% (v/v). The biocatalyst recovered with ethanol addition showed similar specific growth rates (0.03 h(-1)) and dibenzothiophene desulfurization rates (6-7.2 mol l(-1) h(-1)) to those (0.03 h(-1) and 7.1 mol l(-1), respectively) of the biocatalyst recovered with no ethanol addition. The desulfurization activity significantly increased as the number of the repeated recovery and reuse of the biocatalyst.


Asunto(s)
Actinomycetales/crecimiento & desarrollo , Actinomycetales/metabolismo , Técnicas de Cultivo de Célula/métodos , Gasolina , Azufre/metabolismo , Actinomycetales/efectos de los fármacos , Contaminación del Aire/prevención & control , Biodegradación Ambiental , Reactores Biológicos , Catálisis , Centrifugación/métodos , Medios de Cultivo/química , Emulsiones , Etanol/química , Excipientes/química , Petróleo/metabolismo , Control de Calidad , Compuestos de Azufre/metabolismo , Tensión Superficial , Viscosidad
18.
Microbiology (Reading) ; 149(Pt 6): 1523-1532, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12777492

RESUMEN

Thiazolylpeptide GE2270 is a potent antibiotic inhibiting protein synthesis in Gram-positive bacteria. It is produced as a complex of 10 related metabolites, differing mainly in the degree of methylation, by fermentation of the rare actinomycete Planobispora rosea ATCC 53773. Addition of vitamin B12 to the fermentation medium doubled total complex production and markedly changed the relative production of the various GE2270 metabolites, enhancing the biosynthesis of the more methylated component A. Among methylation inhibitors, the addition of sinefungin increased the amount of factor D2, which differs from component A in the lack of a methyl group. Since sinefungin is an S-adenosyl-L-methionine methyltransferase-specific inhibitor, these results indicate that the methylation step converting D2 into A involves an S-adenosyl-L-methionine methyltransferase. Simultaneous supplementation of vitamin B12 and sinefungin led to a twofold increase in D2 concentration, showing that vitamin B12, in addition to having an effect on the late methylation step, exerts a stimulating action on antibiotic backbone synthesis. This is possibly due to its role in an unusual pathway of serine synthesis peculiar to P. rosea metabolism. Finally, fermentation medium modifications were shown to be useful for the production of industrially valuable levels of components A or D2 in the GE2270 complex as starting points for the production of new interesting semi-synthetic antibiotics.


Asunto(s)
Actinomycetales/metabolismo , Adenosina/análogos & derivados , Antibacterianos/biosíntesis , Péptidos Cíclicos/metabolismo , Péptidos , Tiazoles/metabolismo , Actinomycetales/efectos de los fármacos , Adenosina/farmacología , Antibacterianos/química , Medios de Cultivo , Interacciones Farmacológicas , Fermentación , Metionina/metabolismo , Metionina/farmacología , Metilación/efectos de los fármacos , Estructura Molecular , Péptidos Cíclicos/química , Tiazoles/química , Vitamina B 12/metabolismo , Vitamina B 12/farmacología
19.
Mol Plant Microbe Interact ; 14(7): 925-8, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11437268

RESUMEN

Fragarin, an antibiotic that was isolated and purified from a soluble fraction of strawberry leaves, may be a new type of preformed antimicrobial compound (phytoanticipin). Here, we report that the growth and oxygen consumption of the phytopathogenic bacterium Clavibacter michiganensis were rapidly inhibited after the addition of fragarin to cultures. Also, dissipation of the membrane potential and an increase of cell membrane permeability were observed in the presence of fragarin. The ability of fragarin to dissipate the membrane potential was confirmed with the use of small unilamellar liposomes made with lipids extracted from C. michiganensis. Our results suggest that fragarin is able to act at the membrane level, and that this action is correlated with a decrease in cell viability.


Asunto(s)
Actinomycetales/efectos de los fármacos , Actinomycetales/patogenicidad , Antibacterianos/farmacología , Actinomycetales/crecimiento & desarrollo , Actinomycetales/metabolismo , Antibacterianos/aislamiento & purificación , Permeabilidad de la Membrana Celular/efectos de los fármacos , Citoplasma/efectos de los fármacos , Frutas/microbiología , Frutas/fisiología , Potenciales de la Membrana/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Sesquiterpenos , Terpenos , Fitoalexinas
20.
J Biotechnol ; 88(3): 277-82, 2001 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-11434973

RESUMEN

Artemisia annua, well recognized for its production of antimalarial drug artemisinin, is seldom attacked by any of phytopathogenic fungi, which could be partially associated with the presence of endophytes. Present investigation is aiming at disclosing whether the endophytes inside A. annua produce antifungal substances. A total of 39 endophytes were isolated and fermented, and the ferment broth was evaluated in vitro for the antifungal activity against crop-threatening fungi Gaeumannomyces graminis var. tritici, Rhizoctonia cerealis, Helminthosporium sativum, Fusarium graminearum, Gerlachia nivalis and Phytophthora capsici. These plant pathogens are still causing wheat take-all, sharp eyespot, common rot, scab, snow mould, and pepper phytophthora blight, respectively. Out of 39 endophytes investigated, 21 can produce in vitro substances that are inhibitory to all or a few of the tested phytopathogens whereas the rest yielded nothing active. Moreover, the most active broth of endophyte IV403 was extracted with EtOAc and n-butanol, and comparisons of the antifungal activity of the extracts indicated that the major active metabolites were EtOAc-extractable.


Asunto(s)
Actinomycetales/efectos de los fármacos , Antifúngicos/farmacología , Artemisia/química , Hongos/fisiología , Actinomycetales/fisiología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Artemisia/microbiología , Fermentación , Hongos/efectos de los fármacos , Hongos/metabolismo , Pruebas de Sensibilidad Microbiana , Simbiosis
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