ABSTRACT
An ability of phosphate-mobilizing bacteria, related to four species of Bacillus genus, to colonize the cucumber root zone has been investigated. It has been found that all the studied strains can adapt to the root zone of those plants colonizing its parts to different extent. Essential nonuniformity of the root surface populating with bacteria is noted. Microcolonies of these organisms are formed in some root zones. This peculiarity is probably caused both by the difference in the number and composition of exudates of some zones of the plant roots, and by peculiarities of trophic requirements of the strains of studied bacteria The paper is presented in Ukrainian.
Subject(s)
Bacillus/growth & development , Cucumis sativus/microbiology , Phosphates/metabolism , Rhizome/microbiology , Bacillus/metabolism , Bacillus/ultrastructure , Cucumis sativus/growth & development , Cucumis sativus/metabolism , Cucumis sativus/ultrastructure , Microscopy, Electron, Scanning , Rhizome/growth & development , Rhizome/metabolism , Rhizome/ultrastructureABSTRACT
The dependence of Azotobacter vinelandii IMV V-7076 and Bacillus subtilis IMV V-7023 adhesion on some parameters of dispersion media (pH, Ca 2+ ions presence) has been investigated. It has been determined that a decrease of bacteria negative charge determines an increase of the degree of their attachment to abiotic surface (glass) that corresponds to physicochemical regularities of the given process. The adhesion of bacteria on the biotic surface (cucumber roots) is not subordinated to generally accepted ideas, according to which the electrostatic repulsion between the interacting objects is one of factors that determines the adhesion effectiveness.
Subject(s)
Azotobacter vinelandii/growth & development , Bacillus subtilis/growth & development , Bacterial Adhesion , Bacterial Adhesion/physiology , Calcium Compounds/chemistry , Cations, Divalent/chemistry , Cucumis sativus/microbiology , Culture Media , Glass , Hydrogen-Ion Concentration , Nitrates/chemistry , Plant Roots/microbiology , Static Electricity , Surface PropertiesABSTRACT
Bacterization of seeds of several plant species with Azotobacter vinelandii suspension stimulates their germination to different degrees. This demonstrates that seeds of different species display different sensitivity to the biologically active substances accumulating in the culture liquid of these bacteria. The adhesion patterns of these bacteria to cucumber roots were studied. The maximal number of cells adhered to the root surface at the phase of culture logarithmic growth (24 h), when they were motile. The loss of motility in the stationary growth phase (72 h) decreased the number of cells adhered to roots by 80%.
