Research Mineral PM2.5 On Vivo Bacteria In Recent Film Role And Activity

Atmospheric particulate matter （particulate matter, PM） artificial and natural ultrafine particle formation is one of the main sources of air pollution, in which ultra-fine mineral particles and microorganisms is an important part of atmospheric particulate matter. In addition to ultra-fine mineral fine particles can be used as a carrier transporting microbes to survive nutrient source, but also may be due to its size effect, surface active and have an impact on the chemical composition and other microbes coexist. In addition, the ultra-fine mineral particles effect the normal flora through breathing and nasal passages, mouth and other body organs or the skin surface, whether it will increase the degree of microbiological hazards to human health and the expansion of transmission and so on is not very clear, and therefore to carry out mineral fine particles the membrane material and activity of microbial community work.The research of quartz, calcite, nano-silica （Nano-SiO₂）, （Nano-CaCO₃） mineral fine particles objects, Escherichia coli, Staphylococcus aureus microbes objects studied fine mineral particles and microorganisms in PBS buffer liquid/medium system active oxygen radicals, hydroxyl radical change. And the impact of fine particles of mineral matter of active microbial cells. Use convenient, reproducible strong fluorescence spectrophotometric detection system role hydroxyl radical （·OH）, the detection system of reactive oxygen species （ROS） and intracellular reactive oxygen species. Microbial surface topography changes after the use of SEM/infrared spectrum of action groups. The use of automatic biochemical analyzer,SOD kit analysis of changes in the microbial cell active substance.With mineral fine particle concentration increased interaction system ROS, hydroxyl radical generation capacity was significantly increased in a dose-response relationship. Reaction time significantly affect the ability of the different roles of the system to release free radicals, in a time-effect relationship. Media interaction system, the increase over time, each reaction system increases ROS fluorescence intensity. Ore of different types, the ability to generate free radicals in a buffer solution different within 24h, mineral fine particles of different types, different free radicals generated in the reaction system. Medium system ROS generation capability:calcite> Nano-CaCO₃> Quartz>Nano-SiO₂, hydroxyl radical generation capacity: calcite>Nano-CaCO₃> Quartz> Nano-SiO₂. Join dust microbes, the system has a certain degree of reduction of free radicals. Staphylococcus aureus, E.coli added to the system relatively low radicals added to the system.Microorganisms and after 24h quartz mineral particles can cause microbes appear stretched, depression, rupture and other phenomena; nano-silica nanoparticles because it can adhere to the surface of the microorganism, the contact area, cell morphology appeared broken, cracked phenomenon. Calcite reaction occurs with PBS, the occurrence of corrosion, bacterial adhesion surface, due to the electrostatic interaction, extracellular products exist between the bacterial adhesion and aggregation in one piece. High concentrations of calcite/nano calcium carbonate is added, not only have an impact on the bacterial surface protein group, but also have an impact on the bacterial surface phosphodiester groups; quartz/nano-silica added phosphodiester symmetric stretching vibration peak group antisymmetric vibration peak gradually disappearing, protein molecules symmetric bending vibration peak of methyl red shift.Fine mineral particles and microorganisms 24h, mineral fine particles are added will lead to increased bacterial intracellular reactive oxygen species, and showed concentration-dose effects. Due to increased reactive oxygen species, superoxide dismutase start free radical scavenging activity has declined it. Because the fine particles are added to the mineral causing bacteria permeability changes, LDH release, and its activity has increased. It was found that fine particles of mineral stimulated ROS fluorescence intensity gap between E. coli and S. aureus cells, due to the negative E. coli bacteria, the cell wall thickness of 10nm, but its structure is complicated by the peptidoglycan, lipopolysaccharide, lipid protein and other components. Because of the complex structure-negative bacteria cell wall stimulate intracellular ROS production in cells smaller amount. Staphylococcus aureus-positive bacteria, cell wall peptidoglycan and teichoic acid composition only, but because of the thickness of simple structure, large external stimuli, fine mineral particles and positive bacteria occur within a relatively large amount of ROS action to stimulate the cells.