ABSTRACT
There is naturally reciprocity between roots and microbiocenoses. They cause profound modifications in the structure of soils and their grain size. They develop mineral and organic elements, including lectins and enzymes. The external microbism of vegetals was qualified as "epiphytic". The Rhizobium occupies a privileged place in the attachment mechanisms of atmospheric nitrogen, but the possible role of other microorganisms cannot be excluded. Endotrophic and ectotrophic microbes participate in the process at other levels. The plural of soil and sediment should be used straightaway due to their extreme diversity. Living beings such as plankton, invertebrates (notably mollusks), and aquatic plants, but also extremely varied inert materials that shelter vast bacterial populations, can be found. Industrial materials are included in this group. The adherent bacteria most often lose their usual morphology in culture media. No one questions the important role that plankton plays in the stocking and transportation of microorganisms in water.
