Study Of The Motility Of Carbonate Mineralized Bacteria And Biomineralization

Biomineralization is a common phenomenon in nature.Organisms can produce functional materials with multi-ordered structures through biomineralization.In the process of biomineralization,organic matrix is involved in the formation of inorganic materials,so that the formed composite material has excellent performance.Therefore,it is of great significance to apply biomineralization through simulation or bionic methods to actual production.Many microorganisms in nature can induce calcium carbonate deposition,such as Sporosarcina pasteurii and Pseudomonas aeruginosa.These bacteria can be collectively referred to as carbonate mineralized bacteria.It is of great significance to study the physiological characteristics of carbonate mineralized bacteria to further elucidate the mechanism of inducing carbonate mineralization.At the same time,how to apply biomineralization to actual production is also a question that needs to be explored.The purpose of this study was to reveal the movement behavior of the carbonate mineralized bacteria and to explore the dynamic process and application of the biomineralization in the case of Sporosarcina pasteurii.First of all,this study developed a method of quantitative characterization of bacterial movement at a singlecell resolution by high-throughput bacterial microscopy tracking technique,and studied the motion behavior of Sporosarcina pasteurii and Pseudomonas aeruginosa.The results of the study showed that for Sporosarcina pasteurii,we did not observe its twitching on the surface of ordinary materials.Its swimming near surface in the liquid can be divided into two motility behaviours: ‘roaming’,characterized by meandering trajectories,and ‘orbiting’,characterized by repetitive high-curvature orbits.The speed of Sporosarcina pasteurii was different at different growth stages,and the speed of movement was faster in the middle logarithm.With the extension of growth stage,the bacteria showed less and less activity.In addition,we found that when calcium carbonate formed in the environment,the delay period of bacteria was longer and the activity of bacteria was lower than the non calcium medium at the same time by comparing the difference in the movement behavior of bacteria under the condition of calcium ion and no calcium ion.The results showed that the better the bacterial activity,the more inclined to do the roaming movement with smaller curvature.The results indicate the effect of biomineralization on the movement of bacteria.At the same time,for Pseudomonas aeruginosa,we mainly studied the surface movement behavior of mutants associated with polysaccharide Psl,which laid the foundation for the followup study of the role of polysaccharide in biomineralization.Secondly,we obtained realtime process of mineralization induced by Sporosarcina pasteurii.On this basis,we try to prepare porous calcium carbonate crystal by biomineralization.And the porous structure of calcite crystal was obtained by the in-situ crystallization method using the colloidal crystal template method through the transformation process from amorphous calcium carbonate to calcite calcium carbonate crystals during the deposition process of calcium carbonate induced by microorganisms.The method of using microorganisms to form porous crystals provides a synthetic route for the preparation of nanopatterned inorganic single crystal materials.