Dyrenko D. Peculiarities of Azotobacter vinelandii IMV V-7076 and Bacillus subtilis IMV V-7023 with abiotic and biotic surfaces.

Dissertation is dedicated to investigation of phosphate mobilizing and nitrogenphixed bacteria adhesion to biotic and abiotic surfaces and their colonization of plants roots. Dependence of A. vinelandii and B. subtilis adhesion from physical-chemical factors of dispersed media was investigated. It was shown that bacteria negative charge reduce leads to increase of attached cells number to abiotic surface (glass), which corresponds to physical-chemical regularities of the given process. Bacterial adhesion on biotic surface (cucumbers roots) doesn't depend on generally accepted idea that permits to assume the presence of specific interaction between certain sites of microorganisms cells surface and plants. It was determined the Bacillus subtilis IMV V-7023 adhesion dependence to different nature surfaces from the stage of a culture development and the environment temperature. It was shown that bacteria of A. vinelandii and B. subtilis adhesion to solid surfaces depends essentially from cells movement. It was determined that the most intensive attachment of A. vinelandii cells to biotic surface (Konkurent sort cucumbers roots) was observed during the first 5 min. of interaction. During this period the number of adhesion cells was increased in 5 times in comparison with bacteria, which had attached to roots during the first minute. It was ascertained, that only 4% of A. vinelandii cells is adhesioned on cucumbers roots from their quantity in initial suspension. Increase of bacteria number in suspension has led to cells adhesion increase in 4,3 times on roots in 2,2 times. Further increase of bacteria population density in suspension was accompanied with less intensive increase of their number on roots. It was determined, that lectins are localized on the surface of phosphate mobilizing bacteria of B. subtilis. Their carbohydrate specificity was determined. The interaction of bacterial cells with carbohydrate D-glucosamine hydrochloride reduced considerably the level of cells adhesion to the Konkurent sort cucumbers roots. A. vinelandii and B. subtilis with different efficiency adhesion to cucumbers roots and colonized their surface concentrated mainly in the middle and its above parts. It was determined, that the process of roots colonization by the investigated bacteria took parts from the first twenty-four hours of plants growth. Introduction of plants seedlings of B. subtilis into cultivation media has promoted their joint growth and development. It took place at the expense of accumulation in the media a number of biologically active substances - aminoacids and monosaccharides and their use in strophic needs, by bacteria as well as plants.