Gram négatifLes bactéries à Gram négatif sont mises en évidence par une technique de coloration appelée coloration de Gram. Les bactéries à Gram négatif apparaissent alors roses au microscope. La technique de coloration révèle des caractéristiques membranaires et de paroi de la bactérie. Néanmoins, il ne s'agit pas d'un facteur de classement phylogénétique : en effet, les groupes Gram + et Gram − ne sont ni l'un ni l'autre monophylétiques.
Microbial intelligenceMicrobial intelligence (known as bacterial intelligence) is the intelligence shown by microorganisms. The concept encompasses complex adaptive behavior shown by single cells, and altruistic or cooperative behavior in populations of like or unlike cells mediated by chemical signalling that induces physiological or behavioral changes in cells and influences colony structures. Complex cells, like protozoa or algae, show remarkable abilities to organize themselves in changing circumstances.
Adhésine bactérienneAdhesins are cell-surface components or appendages of bacteria that facilitate adhesion or adherence to other cells or to surfaces, usually in the host they are infecting or living in. Adhesins are a type of virulence factor. Adherence is an essential step in bacterial pathogenesis or infection, required for colonizing a new host. Adhesion and bacterial adhesins are also a potential target for prophylaxis or treatment of bacterial infections. Bacteria are typically found attached to and living in close association with surfaces.
Électrophorèse sur gelalt=Appareil à électrophorèse sur gel d'agarose|vignette|Appareil pour électrophorèse d'ADN en gel d'agarose. Le gel est horizontal baigne dans le tampon qui remplit la cuve. L'ADN est déposé dans des puits à une extrémité du gel. L'alimentation en arrière-plan fournit la tension électrique continue qui permet la migration des fragments d'ADN dans le gel. L'électrophorèse sur gel est une variante de l'électrophorèse de zones.
Groundwater pollutionGroundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution.
Dépollutionvignette|Des bénévoles nettoient les côtes après la catastrophe du Prestige. La dépollution désigne l'élimination des pollutions et des contaminations des milieux ambiants tels les sols, les nappes phréatiques, les sédiments ou les eaux de surface. Les enjeux de la dépollution sont souvent financiers mais aussi d'intérêt général : protection de la santé publique et de l'environnement, ou par exemple dans le cas d'un site industriel ou commercial désaffecté, la réutilisation.
Environmental effects of miningEnvironmental effects of mining can occur at local, regional, and global scales through direct and indirect mining practices. Mining can cause in erosion, sinkholes, loss of biodiversity, or the contamination of soil, groundwater, and surface water by chemicals emitted from mining processes. These processes also affect the atmosphere through carbon emissions which contributes to climate change.
Élément-trace métalliqueLa notion d’éléments-traces métalliques, ou ETM tend à remplacer celle de métaux lourds mal définie car englobant des métaux toxiques réellement lourds à d'autres (métalloïdes) l'étant moins. Tous les ETM sont toxiques ou toxiques au-delà d'un certain seuil et certains sont radioactifs (radionucléides). Leurs concentrations environnementales (eau, air, sol, organismes) résultent d'apports anthropiques (industrie, transports...
Toxic heavy metalA toxic heavy metal is any relatively dense metal or metalloid that is noted for its potential toxicity, especially in environmental contexts. The term has particular application to cadmium, mercury and lead, all of which appear in the World Health Organization's list of 10 chemicals of major public concern. Other examples include manganese, chromium, cobalt, nickel, copper, zinc, silver, antimony and thallium. Heavy metals are found naturally in the earth.
ComammoxComammox (COMplete AMMonia OXidation) is the name attributed to an organism that can convert ammonia into nitrite and then into nitrate through the process of nitrification. Nitrification has traditionally thought to be a two-step process, where ammonia-oxidizing bacteria and archaea oxidize ammonia to nitrite and then nitrite-oxidizing bacteria convert to nitrate. Complete conversion of ammonia into nitrate by a single microorganism was first predicted in 2006.
