The variation of actinobacteria species from a vicia sativa cultivated soil microhabitat

Actinobacteria is a fairly complex group, intermediate between bacteria and filamentous fungi involved in producing some infection, in the case of pathogenic strains and recycling of organic matter, as in the case of nonpathogenic actinobacteria. Literature data have surprised many plant-microorganism interaction, on the one hand making reference to the mineralization processes involving microorganisms by whom plants necessary nutrients are released, and on the other hand underlines the influence of plants on the quantity and quality of microbial population in root area as a result of exudates removed in the natural environment. Actinobacteria from Frankia genus are counted among bacteria being able to fix nitrogen, and those from the genus Streptomyces are major producers of antibiotics and numerous secondary metabolites. This paper presents the study of the composition of Streptomyces genus actinobacteria community from a moderately gleyed eutricambosoil, grown with vetch (Vicia sativa). The soil is located in the western part of Romania. Biological material sampling was conducted in October, the depth of 0-20 cm. Isolation and studies of this bacterial group were performed "in vitro", on Gause 1 culture media. Actinobacteria were collected from four areas (biotopes): the plot uncultivated with Vicia sativa (control variant), the far rhizospheric area, the hairy root and root areas of vetch plant. Based on effectuated observations, it was noticed that soil microhabitats contain a variety of actinobacteria and S. albosporeus, S. aureus, S. griseus, S.albus, S. nigrescens, S. lavenduleroseus, S. helvolus. Numerically dominant species in tested soil samples are: S. griseus, S. albus and S. albosporeus.