Open AccessINFLUENCE OF ULTRAVIOLET RADIATION ON THE VIABILITY OF VEGETATIVE CELLS AND CYSTS OF AZOTOBACTER CHROOCOCUM 2.1
Author(s) -
O. M. Bilokonska
Publication year - 2018
Publication title -
sìlʹsʹkogospodarsʹka mìkrobìologìâ
Language(s) - English
Resource type - Journals
ISSN - 1997-3004
DOI - 10.35868/1997-3004.28.86-91
Subject(s) - azotobacter chroococcum , azotobacter , biology , polysaccharide , irradiation , microorganism , microbiology and biotechnology , bacteria , botany , chemistry , biochemistry , genetics , physics , nuclear physics
Objective. Study the influence of ultraviolet radiation (UV radiation) on the preservation of cysts and vegetative cells of Azotobacter chroococcum 2.1 in the digest medium and seeds of cucumber, including for the use of the polysaccharide-protein complex.
Methods. Microbiological, microscopic, physical, statistical.
Results. Significant negative effect of UV radiation on the viability of A. chroococcum 2.1 was shown. Cysts of A. chroococcum 2.1 are more resistant to UV radiation than vegetative cells. The influence of UV radiation on the viability of azotobacter depends on the time during which the bacterial cells were irradiated. In the digest medium, the number of cysts of A. chroococcum 2.1 was higher than the vegetative cells by 88 % at the minimum exposure time. Under the action of UV radiation for 60 seconds, all vegetative cells in the medium died, while a small number of cysts remained. On bacterized seeds, due to the folded surface of the shell, viable cysts of azotobacter, unlike vegetative cells, was observed even for irradiation within 30 minutes. To reduce the negative effects of UV radiation, the polysaccharide-protein complex (PPC) has been used, ant it contributed in lengthening the viability of microorganism cells. The highest survival of bacterial cells was observed in the variant with A. chroococcum 2.1 in the form of cysts with the addition of PPC. Under such conditions, vegetative cells are detected only in the variant with the addition of PPC.
Conclusion. UV radiation negatively affects the survival of A. chroococcum 2.1 both on the digest medium and on the seeds of the cucumber, while vegetative cells are more likely to die than cysts. To improve the survival of A. chroococcum 2.1 seeds in the form of cysts and vegetative cells, it is advisable to use the polysaccharide-protein complex. The obtained data are the basis for further research on the possibilities of preservation of viable cells of bacteria of the genus Azotobacter on the seed under the influence of unfavourable environmental factors.