Lavrent'yeva K. Biological properties of soil bacteria with dissolving capacity of tribasic calcium phosphate

Thesis Candidate's degree in speciality 03.00.07 - Microbiology. - D.K. Zabolotny Institute of microbiology and virology, NAS of Ukraine. - Kyiv, 2011. Thesis deals with isolation from the culture plants rhizosphere and researching of biological properties of soil bacteria strains with dissolving capacity of tribasic calcium phosphate, and development of new concept to estimate their phosphate-solubilizing activity. For the first time it was carried out the screening of soil bacteria isolates from the culture plants rhizosphere in Pridneprovsk region in according with their ability to dissolved tribasic calcium phosphate. It was shown a dissolving of tribasic calcium phosphate was complicated and depended on physiology-biochemical parameters of bacteria growth. For the first time it was proved the estimation of bacteria phosphorus-solubilizing activities and selection of the activest strains are nessessary determined Рі-contents in three fractions: bacteria biomass, supernatant of culture liquid and residual tribasic calcium phosphate. In terms of Рі-sum in two fractions (bacteria biomass and supernatant of culture liquid) it was determined high phosphorus- solubilizing activity of Pseudomonas putida 5 and Enterobacter dissolvens 17 - according to 96,7 % and 90,3 % Рі from its initial content in tribasic calcium phosphate. In laboratory experiment it was shown the addition into non-sterile soil of bacteria strains P. putida 5 and E. dissolvens 17 at concentrations 104 and 105 cells/g effects positively on morphometric and physiology-biochemical parameters of winter wheat plants, activates process of phosphorus mobilization from mineral soil fraction Са-Р and increases of soil general mobile phosphorus. Key words: tribasic calcium phosphate, phosphorus-mobilizing bacteria, phosphorus-mobilizing activity, bacterization, winter wheat plants.