RESUMEN
AIM: Study the effect of microgravitation on the formation of Lactobacillusplantarum 8PA-3 bacterial biofilms in the conditions of space flight. MATERIALS AND METHODS: Information on the ef- fect of microgravitation on the development of biofilms was obtained during study of L. plantarum 8PA-3 probiotic lactobacilli in special equipment in the process of execution of space experiments in the Russian segment of the International Space Station. Comparative analysis of growth of plankton and biofilm forms of cells developing in the conditions of space flight and surface conditions was carried out by microbiologic and electron-microscopy methods using scanning and transmission electron microscopy. RESULTS: Accelerated dynamics of formation of L. plantarum 8PA-3 lactobacilli biofim on the surface polymer substrate was shown for the first time during the space experiment. Microbiological anfalysis of the bacterial culture has also confirmed the accelerated growth of L.plantarum 8PA-3 under microgravitation compared with surface conditions. Ultrastructure of plankton form of L. plantarum 8PA-3 taking part in formation of biofilms inconditions ofmicrogravitationwas detected for the first time inthe space experiment. CONCLUSION: Data on comparative electron-microscopic analysis obtained in space experiments are important for scientific justification of the effect of icrogravitation on bacterial communities developig as biofilms - the most natural form of existence of microorganisms. The results obtained could be taken into consideration during creation of novel antibacterial means and disinfectants as well as methods of treatment of surfaces of modules of piloted space complexes that could allow to clarify methods of effective prophylaxis of biofilm spread which pose a risk of health of the crew and normal functioning of equipment in the International Space Station.
Asunto(s)
Biopelículas/crecimiento & desarrollo , Lactobacillus plantarum/fisiología , Vuelo Espacial , Ingravidez , HumanosRESUMEN
AIM: Detection of bactericidal effect of pulse-periodic corona discharge (PPCD) on cells and biofilms of Escherichia coli M17. MATERIALS AND METHODS: A gas-discharge device was created based on PPCD in air with power supply parameters: amplitude values of voltage of 30 - 60 kV, pulse repetition rate of 250 - 400 kHz. Ultrastructure changes in cells and biofilms of E. coli M17, affected by PPCD, generated in air, were studied by typical methods of transmission electron microscopy. RESULTS: Disturbances of integrity of surface and abyssal structures of biofilms, as well as changes of morphological properties of E. coli M17 cells, characteristic for sub-lethal heat impact, were detected. Destructive changes of bacterial cells were developed by formation of focal disturbance of cytoplasmic membrane, extension of periplasmic space, formation of globular structures, characteristic for heat effect, and destruction of cytoplasm. CONCLUSION: Bactericidal effect of PPCD on E. coli M17 cells as part of biofilms was shown. Destructive morphological changes in cells and biofilms of E. coli M17 after the effect of PPCD were detected for the first time on electron-microscopic level.