Bogdan Y. Mutagenic and protective activity of Pseudomonas syringae pv. atrofaciens in bacterial and plant test-system

Dissertation to obtain the scientific degree of the candidate of biological sciences in speciality 03.00.07 - microbiology. - Zabolotny Institute of Microbiology and Virology National Academy of Sciences of Ukraine, Kiev, 2010. Dissertation is devoted to the study of mutagenic and protective properties of lipopolysaccharides preparations (LPS) of two Pseudomonas syringae pv. atrofaciens strains, which differ in pathogenicity in relation to wheat and antigen composition, and also to the study of cultural liquid mutagenic activity of these strains, neopathotype strains of Pseudomonas syringae and saprophytic bacteria. LPS preparations of P. syringae pv. atrofaciens strains 9400 and 9417obtained by extraction with 0,85 % solution of sodium chloride have typical chemical composition for bacteria of these species. It was established that LPS preparations and the 10 fold concentrated cultural liquid filtrates (CCLF) of P. syringae pv. atrofaciens strains 9400 and 9417 are not mutagenic in bacterial test-system with Salmonella typhimurium strains ТА98 and ТА100. The mutagenic activity of CCLF of neopathotype strains P. syrіngae pv. syrіngae UKM B-1027 and P. syrіngae pv. atrofacіens UKM B-1011, and saprophytic strains Pantoea agglomerans 1а and П324, Bacillus pumilus Е392а also was not detected. At the same time in this test-system the preparations of LPS reveal antimutagenic activity against potassium dichromate and N-methyl-N'-nitro-N'-nitrosoguanidine. It was found that LPS preparations of P. syringae pv. atrofaciens strains 9400 and 9417 possess the ability to prevent the tumor formation induced by Agrobacterium tumefaciens on potato explants. It was shown that in Allium cepa-test the LPS preparations of P. syringae pv. atrofaciens strains 9400 and 9417, and the cultural liquid of P. syringae pv. atrofaciens 9417 induce the destruction of chromosomes. It was established that the LPS preparations of P. syringae pv. atrofaciens strains 9400 and 9417, and the cultural liquid of these strains and P. agglomerans П324 increase the peroxydase activity and the content of malonaldehyde in the sprouts of A. cepa. It can indicate oxidative stress in plants during the action of bioactive microbal compounds on them.