Search results for " microorganism"
showing 10 items of 81 documents
Nitric oxide: a multitask player in plant–microorganism symbioses
2016
Symbiosis is a close and often long-term interaction between two different biological organisms, i.e. plants or fungi and microorganisms. Two main types of plant–microorganism interactions, mutualistic and cooperative, have been categorized. Mutualistic interactions, including nitrogen-fixing and mycorrhizal symbioses, refer to mostly obligate relationships between a host plant and a symbiont microorganism. Cooperative interactions correspond to less obligate and specific relationships. They involve microorganisms, referred to as plant growth-promoting rhizobia (PGPR), able to colonize root surface or inner tissues. Lichens are symbiotic associations of host fungi and photosynthetic partner…
Editorial: Exploring Plant Rhizosphere, Phyllosphere and Endosphere Microbial Communities to Improve the Management of Polluted Sites
2021
International audience
Determining Cellulolytic Activity of Microorganisms
2020
Abstract Decomposition of cellulose to glucose requires complex cooperation of glycoside hydrolase enzymes. As a result of glycoside β-1,4 bonds hydrolysis, shorter chains of cellulose, oligodextrin, cellobiose and glucose are created. A number of bacteria and fungi demonstrate the capacity to degrade cellulose. Their activity can be assessed with the use of qualitative and quantitative methods. Qualitative methods with the use of e.g. Congo red, are used in screening studies, however, they do not provide information about the quantity of the produced enzyme. Spectrophotometric methods are more accurate and they measure the quantities of reducing sugars with the use of appropriate substrate…
Characterization of kefir-like beverages produced from vegetable juices
2016
The aim of this work was to develop new non-dairy fermented beverages using vegetable juices as fermentable substrates. Carrot, fennel, melon, onion, tomato and strawberry juices underwent back-slopping fermentations, carried out by water kefir microorganisms. Results indicated that lactic acid bacteria and yeasts were capable of growing in the juices tested. Melon juice registered the highest numbers of microorganisms. Almost all juices underwent a lactic fermentation. After fermentation, there was observance of a decrease of the soluble solid content and an increase of the number of volatile organic compounds. In particular, esters were present in high amounts after the fermentation, espe…
Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula.
2017
The infection caused by Trichomonas vaginalis is the most common but overlooked non-viral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5-nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII). In addition, the isolated saponin fraction improved the metronidazole effect against a me…
Volatile compounds produced by the ligninolytic fungus Phlebia radiata Fr. (Basidiomycetes) and influence of the strain specificity on the odorous pr…
1989
Abstract The odorous volatile compounds produced by 3 strains (out of 25 strains tested) of Phlebia radiata Fr. were investigated on six synthetic media and identified by GC-MS analysis. One of the 3 strains was odourless. Aromatic primary alcohols and a sesquiterpenic alcohol, α-bisabolol, were the most abundant metabolites for both of the other strains, which exhibited similar flavours and a similar gas chromatographic profile.
Extremophilic microorganisms from natural and artificial environments: Bioprospecting and Biotechnological Applications
2022
La Tierra es el hogar de una gran biodiversidad de microorganismos, que recientemente se ha estimado en 10(12) o más taxones microbianos que habitan nuestro planeta. Durante décadas, se han explorado los ambientes naturales para estudiar sus comunidades microbianas, así como los mecanismos de adaptación específicos de las especies que los componen y sus potenciales aplicaciones biotecnológicas. No solo los entornos naturales sino también los artificiales tienen interés como fuentes de diversidad microbiana. Investigaciones anteriores sobre el microbioma de los productos hechos por el hombre revelaron que los dispositivos artificiales con un diseño y un procedimiento de operación estándar re…
Epidemiología molecular y genómica de aislados resistentes de Pseudomonas aeruginosa de origen hospitalario.
2019
Pseudomonas aeruginosa es un patógeno frecuente en entornos hospitalarios que acumula multitud de resistencias a antibióticos. Ante la dificultad de encontrar tratamiento efectivo, los pacientes están mucho tiempo colonizados y aumenta la probabilidad de transmisión. El principal objetivo del presente trabajo ha sido mostrar cómo el estudio evolutivo a nivel de genomas completos puede ser útil para la detección de transmisiones a diferentes niveles. Se decidió aplicar la misma metodología de reconstrucción de la filogenia a partir de las variantes encontradas en genomas completos que además se dataron por métodos bayesianos. Para ello, hemos contado con muestras de P. aeruginosa multirresis…
Foaming estimation tests in activated sludge systems.
2005
Persistent biological foaming phenomena in activated sludge systems due to excess of filamentous microorganisms with hydrophobic properties, such as GALO, Microthrix parvicella and others, are frequently reported everywhere. Nevertheless, even if the number of plants affected by this trouble is high, presently there are no suitable general methods to evaluate properly the phenomenon. This paper reports on the results of a series of foam tests (Scum Index, Foam Rating), of hydrophobicity measurements of activated sludge (mixed liquor and foam) and measurements of extension of aeration tank covered by foam surfaces. The data obtained by using the above indicated methods are clearly correlated…
Toxicity assessment and biodegradation potential of water-soluble sludge containing 2,4,6-trinitrotoluen
2013
The water-soluble phase of trinitrotoluene-containing sludge (SLP) was characterized with regard to trinitrotoluene (TNT) concentration, ecotoxicity, and a model biodegradation experiment as evaluation criteria for further development of appropriate treatment technologies. SLP contained 67.8 mg TNT/l. The results of germination and root-elongation tests indicated that SLP had a species-specific phytotoxic effect. The results of a 21 day degradation experiment demonstrated TNT conversion to 4-amino-2,6-DNT and 2-amino-4,6-DNT, with a simultaneous reduction in the total concentration of nitroaromatics. Addition of inoculum stimulated the TNT degradation process. The presence of the sludge sol…