Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros











Intervalo de año de publicación
1.
Lett Appl Microbiol ; 77(9)2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39191532

RESUMEN

Pelgipeptins, tridecaptins, and elgicins are among the antimicrobials produced by Paenibacillus elgii. Growth in complex media is commonly applied to obtain lipopeptides from culture's supernatant, but it requires further purification. This study aimed to improve the yield of pelgipeptins and tridecaptins using chemically defined media. The kinetics of antimicrobial lipopeptide yield in chemically defined media were evaluated in P. elgii AC13. Pelgipeptins were detected in the supernatant and the culture pellet, but tridecaptins were mainly associated with cell debris or endospores. We investigated whether removing Ca2+ would impair P. elgii sporogenesis, consequently improving the yield of tridecaptin. The kinetics of both lipopeptides in the presence and absence of Ca2+ were quantitatively and qualitatively evaluated and further correlated with the cell cycle. The impairment of P. elgii AC13 sporogenesis had no effect on tridecaptin production, which remained undetected in the supernatant of the culture. On the other hand, the yield of pelgipeptin in a Ca2+-free medium increased. We showed for the first time that the removal of Ca2+ interrupted the sporogenesis in P. elgii and improved the yield of pelgipeptins. However, Ca2+ absence had no effect on tridecaptin yield, which is possibly degraded or associated with other cell debris components.


Asunto(s)
Medios de Cultivo , Lipopéptidos , Paenibacillus , Paenibacillus/metabolismo , Paenibacillus/crecimiento & desarrollo , Lipopéptidos/biosíntesis , Lipopéptidos/metabolismo , Medios de Cultivo/química , Calcio/metabolismo , Esporas Bacterianas/crecimiento & desarrollo , Antibacterianos/biosíntesis , Antibacterianos/farmacología
2.
Rev. argent. microbiol ; Rev. argent. microbiol;51(1): 77-80, mar. 2019. graf
Artículo en Inglés | LILACS | ID: biblio-1041818

RESUMEN

Cohnella is a highly cellulolytic bacterial genus, which can be found in a variety of habitats. The aim of this study was to assess its presence in the digestive tract of termite species collected in North-eastern Argentina: Nasutitermes aquilinus, N. corniger and Cortaritermes fulviceps. Gut homogenates were incubated with cellulosic substrate for bacterial growth. Bacterial 16S rDNA was partially amplified using new primers for Cohnella spp. and cloned. Sequences obtained showed highest similarity (97.2-99.9%) with those of Cohnella spp. previously reported from diverse environments. Phylogenetic analysis tended to group the clones according to their host species and sampling sites. These results indicate the association of Cohnella-related intestinal symbionts with three common Neotropical termites. Their potential industrial application encourages further research.


Cohnella es un género de bacterias celulolíticas que puede ser encontrado en una variedad de hábitats. El propósito de este estudio fue registrar su presencia en el tracto digestivo de termitas (Nasutitermes aquilinus, N. corniger y Cortaritermes fulviceps) colectadas en el noreste argentino (NEA). Se incubaron homogenados de intestinos en sustrato celulósico para multiplicar las bacterias. Utilizando nuevos cebadores para Cohnella spp., se amplificó una porción del ADN ribosomal 16S bacteriano, el cual fue posteriormente clonado. Las secuencias obtenidas mostraron su mayor porcentaje de similitud (97,2-99,9%) con Cohnella spp., previamente reportadas en diversos ambientes. El análisis filogenético tendió a agrupar a los clones de acuerdo a la especie hospedante y al sitio de muestreo. Estos resultados indican que especies de termitas frecuentes en el NEA albergan simbiontes intestinales relacionados con el género Cohnella. Las potenciales aplicaciones industriales de estos microorganismos animan a profundizar los estudios.


Asunto(s)
Isópteros/microbiología , Paenibacillus/aislamiento & purificación , Paenibacillus/crecimiento & desarrollo , Crecimiento Bacteriano/análisis , Análisis de Secuencia de ADN/métodos , Tracto Gastrointestinal/microbiología
3.
Microbiol Res ; 186-187: 16-26, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27242139

RESUMEN

A novel bacterial isolate with polysaccharides degrading activity was identified as Paenibacillus sp., and named Paenibacillus sp. A59. Even though it is a strict mesophile, optimal xylanase activity of the crude enzymatic extract was achieved between 50°C and 70°C and more than 60% of the activity was retained after incubation for 48h at 50°C, indicating thermotolerance of the enzymes involved. The extract was also active on pre-treated sugarcane residue (SCR) and wheat straw, releasing xylobiose and xylose as the main products, therefore confirming its predominantly xylanolytic activity. By zymograms and mass spectrometry of crude enzymatic extracts of xylan or SCR cultures, a 32kDa GH10 beta- 1,4- endoxylanase with xylanase and no CMCase activity was identified. We named this enzyme XynA and it was the only xylanase identified under both conditions assayed, suggesting that it is a good candidate for recombinant expression and evaluation in hemicelluloses deconstruction applications. Also, a protein with two S-layer homology domains (SLH) and a large uncharacterized C-terminal domain as well as an ABC substrate binding protein were identified in crude extracts of SCR cultures. We propose that Paenibacillus sp. A59 uses a system similar to anaerobic and other Gram positive bacteria, with SLH-domain proteins anchoring polysaccharide-degrading enzymes close to the membrane and the substrate binding protein assisting translocation of simple sugars to the cell interior.


Asunto(s)
Endo-1,4-beta Xilanasas/análisis , Lignina/metabolismo , Paenibacillus/enzimología , Paenibacillus/crecimiento & desarrollo , Xilanos/metabolismo , Disacáridos/metabolismo , Electroforesis , Endo-1,4-beta Xilanasas/química , Espectrometría de Masas , Peso Molecular , Tallos de la Planta/metabolismo , Saccharum/metabolismo , Temperatura , Triticum/metabolismo , Xilosa/metabolismo
4.
Braz. j. microbiol ; Braz. j. microbiol;46(4): 977-989, Oct.-Dec. 2015. tab, graf
Artículo en Inglés | LILACS | ID: lil-769669

RESUMEN

Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production). The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L) and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h). Strain 170 had the highest indoleacetic acid (IAA) production (49.2 mg/L) and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase) activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase). The six endophytic bacterial strains were identified to be Paenibacillus and Bacillus strains based on the results of 16S rRNA gene sequencing analysis and their physiological and biochemical characteristics. Results indicate the promising application of endophytic bacteria to the biological control of pathogenic fungi and the improvement of wheat crop growth.


Asunto(s)
Bacillus/clasificación , Bacillus/genética , Bacillus/crecimiento & desarrollo , Bacillus/aislamiento & purificación , Bacillus/metabolismo , Bacillus/microbiología , China/clasificación , China/genética , China/crecimiento & desarrollo , China/aislamiento & purificación , China/metabolismo , China/microbiología , Endófitos/clasificación , Endófitos/genética , Endófitos/crecimiento & desarrollo , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Endófitos/microbiología , Ácidos Indolacéticos/clasificación , Ácidos Indolacéticos/genética , Ácidos Indolacéticos/crecimiento & desarrollo , Ácidos Indolacéticos/aislamiento & purificación , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/microbiología , Lonicera/clasificación , Lonicera/genética , Lonicera/crecimiento & desarrollo , Lonicera/aislamiento & purificación , Lonicera/metabolismo , Lonicera/microbiología , Datos de Secuencia Molecular/clasificación , Datos de Secuencia Molecular/genética , Datos de Secuencia Molecular/crecimiento & desarrollo , Datos de Secuencia Molecular/aislamiento & purificación , Datos de Secuencia Molecular/metabolismo , Datos de Secuencia Molecular/microbiología , Paenibacillus/clasificación , Paenibacillus/genética , Paenibacillus/crecimiento & desarrollo , Paenibacillus/aislamiento & purificación , Paenibacillus/metabolismo , Paenibacillus/microbiología , Filogenia/clasificación , Filogenia/genética , Filogenia/crecimiento & desarrollo , Filogenia/aislamiento & purificación , Filogenia/metabolismo , Filogenia/microbiología , Raíces de Plantas/clasificación , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/aislamiento & purificación , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Sideróforos/clasificación , Sideróforos/genética , Sideróforos/crecimiento & desarrollo , Sideróforos/aislamiento & purificación , Sideróforos/metabolismo , Sideróforos/microbiología , Triticum/clasificación , Triticum/genética , Triticum/crecimiento & desarrollo , Triticum/aislamiento & purificación , Triticum/metabolismo , Triticum/microbiología
5.
Braz J Microbiol ; 46(2): 367-75, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26273251

RESUMEN

The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.


Asunto(s)
Acinetobacter/metabolismo , Ácidos Carboxílicos/metabolismo , Medios de Cultivo/química , Paenibacillus/metabolismo , Fosfatos/metabolismo , Rhizobium tropici/metabolismo , Acinetobacter/crecimiento & desarrollo , Acinetobacter/aislamiento & purificación , Fabaceae/microbiología , Concentración de Iones de Hidrógeno , Paenibacillus/crecimiento & desarrollo , Paenibacillus/aislamiento & purificación , Rhizobium tropici/crecimiento & desarrollo , Rhizobium tropici/aislamiento & purificación , Nódulos de las Raíces de las Plantas/microbiología
6.
Braz. J. Microbiol. ; 46(2): 367-375, Apr.-Jun. 2015. tab, graf
Artículo en Inglés | VETINDEX | ID: vti-481394

RESUMEN

The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.(AU)


Asunto(s)
Acinetobacter/metabolismo , Ácidos Carboxílicos/metabolismo , Medios de Cultivo/química , Paenibacillus/metabolismo , Fosfatos/metabolismo , Rhizobium tropici/metabolismo , Acinetobacter/crecimiento & desarrollo , Acinetobacter/aislamiento & purificación , Fabaceae/microbiología , Concentración de Iones de Hidrógeno , Paenibacillus/crecimiento & desarrollo , Paenibacillus/aislamiento & purificación , Rhizobium tropici/crecimiento & desarrollo , Rhizobium tropici/aislamiento & purificación , Nódulos de las Raíces de las Plantas/microbiología
7.
Braz. j. microbiol ; Braz. j. microbiol;46(2): 367-375, Apr-Jun/2015. tab, graf
Artículo en Inglés | LILACS | ID: lil-749711

RESUMEN

The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.


Asunto(s)
Acinetobacter/metabolismo , Ácidos Carboxílicos/metabolismo , Medios de Cultivo/química , Paenibacillus/metabolismo , Fosfatos/metabolismo , Rhizobium tropici/metabolismo , Acinetobacter/crecimiento & desarrollo , Acinetobacter/aislamiento & purificación , Fabaceae/microbiología , Concentración de Iones de Hidrógeno , Paenibacillus/crecimiento & desarrollo , Paenibacillus/aislamiento & purificación , Rhizobium tropici/crecimiento & desarrollo , Rhizobium tropici/aislamiento & purificación , Nódulos de las Raíces de las Plantas/microbiología
8.
Braz J Microbiol ; 45(1): 193-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24948930

RESUMEN

In screening the culturable endoglucanase-producing bacteria in the rhizosphere of Rhizophora mangle, we found a prevalence of genera Bacillus and Paenibacillus. These bacteria revealed different activities in endoglucolysis and biofilm formation when exposed to specific NaCl concentrations, indicating modulated growth under natural variations in mangrove salinity.


Asunto(s)
Bacillus/enzimología , Celulasa/análisis , Paenibacillus/enzimología , Rhizophoraceae/crecimiento & desarrollo , Rizosfera , Microbiología del Suelo , Bacillus/crecimiento & desarrollo , Bacillus/aislamiento & purificación , Bacillus/fisiología , Biopelículas/crecimiento & desarrollo , Membrana Celular/química , Ácidos Grasos/análisis , Microscopía Electrónica de Rastreo , Paenibacillus/crecimiento & desarrollo , Paenibacillus/aislamiento & purificación , Paenibacillus/fisiología , Cloruro de Sodio/análisis , Suelo/química
9.
Antonie Van Leeuwenhoek ; 97(4): 389-99, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20352404

RESUMEN

Beneficial bacteria interact with plants by colonizing the rhizosphere and roots followed by further spread through the inner tissues, resulting in endophytic colonization. The major factors contributing to these interactions are not always well understood for most bacterial and plant species. It is believed that specific bacterial functions are required for plant colonization, but also from the plant side specific features are needed, such as plant genotype (cultivar) and developmental stage. Via multivariate analysis we present a quantification of the roles of these components on the composition of root-associated and endophytic bacterial communities in potato plants, by weighing the effects of bacterial inoculation, plant genotype and developmental stage. Spontaneous rifampicin resistant mutants of two bacterial endophytes, Paenibacillus sp. strain E119 and Methylobacterium mesophilicum strain SR1.6/6, were introduced into potato plants of three different cultivars (Eersteling, Robijn and Karnico). Densities of both strains in, or attached to potato plants were measured by selective plating, while the effects of bacterial inoculation, plant genotype and developmental stage on the composition of bacterial, Alphaproteobacterial and Paenibacillus species were determined by PCR-denaturing gradient gel-electrophoresis (DGGE). Multivariate analyses revealed that the composition of bacterial communities was mainly driven by cultivar type and plant developmental stage, while Alphaproteobacterial and Paenibacillus communities were mainly influenced by bacterial inoculation. These results are important for better understanding the effects of bacterial inoculations to plants and their possible effects on the indigenous bacterial communities in relation with other plant factors such as genotype and growth stage.


Asunto(s)
Biodiversidad , Methylobacterium/fisiología , Paenibacillus/fisiología , Raíces de Plantas/microbiología , Solanum tuberosum/crecimiento & desarrollo , Solanum tuberosum/microbiología , Simbiosis , Recuento de Colonia Microbiana , Dermatoglifia del ADN , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Poliacrilamida , Genotipo , Methylobacterium/clasificación , Methylobacterium/crecimiento & desarrollo , Datos de Secuencia Molecular , Desnaturalización de Ácido Nucleico , Paenibacillus/clasificación , Paenibacillus/crecimiento & desarrollo , Análisis de Secuencia de ADN , Solanum tuberosum/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA