Induction Of Calcium Carbonate By Two Kinds Of Bacteria

Carbonate rocks are widely distributed in nature, there are also a variety ofmicrobes on the surface of carbonate, microbial metabolism and life activities willhave a great impact on surface of carbonate rocks. Through the role ofmicroorganisms which changes the ion of calcium and carbon dioxide for calciumcarbonate, it is of great significance to reduce greenhouse gases and carbonsequestration study.There are varieties of microorganisms in the surface of carbonate rocks; they notonly absorb nutrients from the surface of carbonate rocks for themselves growth andreproduction, but also by microbial metabolism and secretion the metabolites, e.g. CA,it is can promote CO2hydration. Then adjust the concentration of CO2and HCO3-.These metabolites are important for carbonate rocks. The growth and metabolism ofmicrobe can also change pH of the environment, and then it has great influence for thecarbonate rocks form and resolve. The growth of microorganisms and their metabolicactivity not only can accelerate the weathering of rocks, can also promote or inductionof the synthesis of mineral. Biological sedimentary carbonate phenomena are verycommon in the nature.The research is using the dominant strains-Bacillus cereus and Pseudomonasputida are isolated from the dolomitic surfaces in areas of Karst topographies. Theexperimental method was as follows: a modified beef extract-peptone medium (beefextract3.0g, peptone10g, NaCl5.0g, CaCl22.0g, glass powder2.0g, distilledwater1L and a pH between6.5and7.5) was inoculated with B. cereus and P. putidain order to attempt to induce the synthesis of CaCO3. The sample was then processedby centrifugation every24hours during the7-day cultivation period. The pH,carbonic anhydrase (CA) activity, and the concentrations of both HCO3-and Ca2+of the supernatant fluid were measured. Subsequently, precipitation in the culturemedium was analyzed to confirm, or otherwise, the presence and if present, theformation of CaCO3. Methods used included X-ray diffraction (XRD), ScanningElectron Microscopy (SEM), Transmission Electron, Microscope (TEM) and EnergyDispersive Spectroscopy (EDS). Meanwhile, the carbon source in the carbonate wasclassified by its isotope composition, and the percent conversion of Ca2+was analyzedto know more of the experiment. As the study of carbonate rock karst areas the role ofmicroorganisms in the carbon cycle provides the basic data.The research used the bacterial metabolism induction of calcium carbonatemineralization, Not only helps reduce atmospheric CO2concentration, and willnot cause secondary pollution to environment. Microorganism is widely existsin the nature of organisms, is an important part of nature. This paper adoptedby the two strains bacteria that on the surface of the carbonate, using its fixedconverts CO2into carbonate minerals, for reduce CO2concentration and slowdown the greenhouse effect will play a positive role. And provide a new wayfor carbon sink change, also for the study of the interactions between microbesand minerals provide important guidance.