Bacterial Calcium Carbonate Precipitation Research Articles

Correlation tests between relative light unit and colony forming unit for improving adenosine triphosphate bioluminescence analysis in bacterial consolidation treatments on palaeontological heritage.

In this article bacterial carbonate mineralization treatments are proposed as a novel strategy for decayed fossils and palaeontological heritage conservation; specifically, by means of inoculation of Myxococcus xanthus, a bacterium of proven effectiveness in ornamental stone bioconsolidation. Bioconsolidation treatments can be very effective, stable, nontoxic, environmentally friendly, and chemically compatible with fossil heritage. The method reproduces what nature has been doing for millennia with fossils that have been permineralized by bacterial calcium carbonate precipitation. There is, however, some concern that bacterial inoculation could lead to the growth of undesirable microbiota, which could subsequently damage the fossil substrate. Because of this, the use of bacteria on heritage items must be meticulously monitored and analysis strategies should be carried out to detect bacteria viability during and after treatments. For this purpose, adenosine triphosphate assay is proposed in this article as a fast, affordable, portable, and easy-to-use system for conservators. as ATP assay results are relative and difficult to relate to colony forming unit, this study aims to improve their applicability by examining the correlation between ATP analysis and total viable bacteria count in the specific case of M. xanthus. This research provides reference and correlatable data to obtain an approximate estimation of M. xanthus viable bacterial colonies based on relative light unit data.

Thermoluminescence studies of calcite conducted by bacterial CaCO3 precipitation in organic soil

In this study, the thermoluminescence (TL) properties of the calcite conducted by bacterial calcium carbonate (CaCO3) precipitation (BCCP) in organic soils were investigated. The bacterial calcium carbonate (CaCO3) precipitation (BCCP) is a popular technique and has been applied in a variety of civil and geotechnical engineering applications. For example, bacterial calcium carbonate precipitation fills the gaps on the organic ground and makes cementing it with the biological method using bacteria. The study reveals that the calcium carbonate mineral called as calcite has a clear TL glow curve with four main peaks located around 90, 140, 210 and 240 °C, a wide linear dose response region between 140Gy and 2.3 kGy is observed. In addition, a good reusability is seen in the high temperature peaks. The TL glow curve peaks are not affected by reusability. Although the dosimetric peaks at 210 and 240 °C appear to be nearly constant, the TL peak intensities at 90 °C and 140 °C completely faded after 24 and 336 h storage time, respectively. The activation energies (Ea) and frequency factors (s) for peaks at 90 °C, 140 °C, 210 °C and 240 °C were evaluated via variable heating rate (VHR). The activation energy of the peaks in the TL glow curve is lying between 0.57eV and 1.04 eV.

Applications of BCCP technology on civil engineering – A review

The Bacterial Calcium Carbonate Precipitation (BCCP) technology is a new eco-friendly approach mainly applied for enhancing the properties of building materials (esp. concrete, cement mortar and soil). In this paper, the existing researches related to application of BCCP technology in soil, concrete and cement mortar and their responses were reviewed. The study begins with the note on BCCP method by explaining its general procedure and mechanisms in material stabilization followed by a detailed survey on its effects when applied in building materials like soil, concrete and mortar. Most of the researches prove that this technique have the potential to improve the properties of concrete, cement mortar and soil, by slightly altering the ingredients. In concrete and cement mortar the properties like compressive strength, crack healing capacity, water absorption and durability are studied whereas in soil, shear strength, Unconfined compressive strength (UCS), Split tensile strength (STS), ductility, permeability, viscosity and brittleness are studied. It is stated that this process reduces the toxicity of soil. This work shows that the properties of concrete, mortar and soil mentioned above were enhanced by varying the type and concentration of both cementing materials and bacteria based on the purpose for which the material is used.

Response Surface Methodology for Optimizing Stabilization of Clay Soils Using Bacterial Calcium Carbonate Precipitation

Response Surface Methodology for Optimizing Stabilization of Clay Soils Using Bacterial Calcium Carbonate Precipitation

Performance Study on Stabilization of Fine Grained Clay Soils Using Calcium Source Producing Microbes

In recent years, the method to produce bio-cementation in sand using bacterial calcium carbonate precipitation (BCCP) process has become more popular. The major objective of this research paper is to study the capability of BCCP to enhance the unconfined compressive strength of clayey soils. Two types of bacteria were used to generate calcium carbonate precipitation. The experimental design variables adopted in this study are bacteria types (L. fusiformis and S. pasteurii), soil types (low compressible clay and intermediate compressible clay), types of externally supplied calcium solution (calcium chloride and eggshell solution), molarities of cementing solution (0.25, 0.50, 0.75 and 1.00 M) and curing period (1, 3 and 7 days). The experimental test results showed that the BCCP process significantly improves the unconfined compressive strength (UCS) of both soils. The improvement however varied with bacterial types, soil types, types of externally supplied calcium solution, molarities of cementing solution and curing period. In BCCP treatment, S. pasteurii treated soils give more strength than L. fusiformis because of high urease activity of S. pasteurii in the order 450 U/ml. The maximum improvement ratio was achieved in CL soil (2.51) compared to CI soil (2.26) due to particle sizes. The optimum externally supplied calcium solution and molarity of cementing medium were established as an eggshell solution and 0.50 M, respectively. The images from scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the experimental findings.

A Novel Approach to Isolation and Screening of Calcifying Bacteria for Biotechnological Applications

Bacterial calcium-carbonate precipitation (BCP) has been studied for multiple applications such as remediation, consolidation, and cementation. Isolation and screening of strong calcifying bacteria is the main task of BCP-technique. In this paper, we studied CaCO3 precipitation by different bacteria isolated from a rhizospheric soil in both solid and liquid media. It has been found, through culture-depending studies, that bacteria belonging to Actinobacteria, Gammaproteobacteria, and Alphaproteobacteria are the dominant bacteria involved in CaCO3 precipitation in this environment. Pure and mixed cultures of selected strains were applied for sand biocementation experiments. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the biotreated samples revealed the biological nature of the cementation and the effectiveness of the biodeposition treatment by mixed cultures. X-ray diffraction (XRD) analysis confirmed that all the calcifying strains selected for sand biocementation precipitated CaCO3, mostly in the form of calcite. In this study, Biolog® EcoPlate is evaluated as a useful method for a more targeted choice of the sampling site with the purpose of obtaining interesting candidates for BCP applications. Furthermore, ImageJ software was investigated, for the first time to our knowledge, as a potential method to screen high CaCO3 producer strains.

Effect of carbonic anhydrase and urease on bacterial Calcium carbonate precipitation

Effect of carbonic anhydrase and urease on bacterial Calcium carbonate precipitation

Effect of bacterial calcium carbonate precipitation on compressibility and shear strength of organic soil

In the past few years, the use of bacterial calcium carbonate precipitation has become popular as a ground-improvement technique for sandy soil. However, this technique has not been applied to organic soil. This study focused on bacterial calcium carbonate precipitation and its effect on the compressibility and strength of organic soil. A special injection system was prepared for inducing a bacterial solution into several samples. The bacterial solution was supplied to the samples by gravity for 4 days in specific molds designed for this work. Calcite precipitation was observed by monitoring the changes in the pH value and by measuring the amount of calcium carbonate in the organic soil. The changes in compressibility and strength were measured before and after the bacterial treatment. The test results showed that the pH values in the treatment medium reached the ideal values that are appropriate for calcite precipitation. It was found that the amount of precipitated calcium carbonate in organic soil increased by about 20% in the treated samples compared to that in the untreated samples. Moreover, the test results indicated that the bacterial treatment influenced the compressibility and shear strength of the organic soil. The results were supported by an energy-dispersive x-ray (EDX) analysis.

Bacterail Calcium Carbonate Precipitation in Peat

Bacterial calcium carbonate precipitation has been used to improve strength and permeability of granular soil. Indeed, very encouraging results have been obtained. Commercially available bacteria have been used in this treatment method. This laboratory scale work is aimed to investigate the feasibility of this new improvement technique in peat that has low strength and high compressibility. For this purpose, two-stage works were carried out. In the first stage, isolation of calcite precipitating bacteria from local soil has been investigated. In the second stage, bacteria have been induced into the peat with treatment solution. The amount of precipitated calcite was determined at the end of the treatment. A preliminary direct shear test has been performed on treated and untreated sample to observe the effect of calcite precipitation on shear strength of the peat. Test results have demonstrated that ureolytic and calcite precipitating bacteria could be isolated from local soils. The treatment has indicated that solid calcite particles precipitated in the peat were nearly 16 % by weight. The shear strength test results have shown that precipitated calcite caused cementing effect on the peat particles.

Applicability of biocementation for organic soil and its effect on permeability

In past few years, the use of bacterial calcium carbonate precipitation (biocementation) has become popular as a ground improvement technique for sandy soil. However, this technique was not applied to organic soil. This study focused on bacterial calcium carbonate precipitation and its effect on permeability in organic soil. A special injection system was prepared for inducing bacterial solution to the samples. The bacterial solution supplied to the samples by gravity for 4 days in specific molds designed for this work. Calcite precipitation was observed by monitoring pH value and measuring amount of calcium carbonate. Change in the permeability was measured before and after biocementation. The test results showed that the pH values indicates that the treatment medium is appropriate for calcite precipitation, and amount of precipitated calcium carbonate in organic soil increased about 20% from untreated one. It was also found that the biocementation can be considered as an effective method for reducing permeability of organic soil. The results were supported by Scanning electron microscopy (SEM) analysis and energy-dispersive x-ray (EDX) analysis.

岩溶洞穴微生物沉积碳酸钙研究——以贵州石将军洞为例

岩溶洞穴微生物沉积碳酸钙研究——以贵州石将军洞为例

Bacterial Calcium Carbonate Precipitation in Cave Environments: A Function of Calcium Homeostasis

To determine if microbial species play an active role in the development of calcium carbonate (CaCO 3 ) deposits (speleothems) in cave environments, we isolated 51 culturable bacteria from a coralloid speleothem and tested their ability to dissolve and precipitate CaCO 3 . The majority of these isolates could precipitate CaCO 3 minerals; scanning electron microscopy and X-ray diffractrometry demonstrated that aragonite, calcite and vaterite were produced in this process. Due to the inability of dead cells to precipitate these minerals, this suggested that calcification requires metabolic activity. Given growth of these species on calcium acetate, but the toxicity of Ca 2+ ions to bacteria, we created a loss-of-function gene knock-out in the Ca 2+ ion efflux protein ChaA. The loss of this protein inhibited growth on media containing calcium, suggesting that the need to remove Ca 2+ ions from the cell may drive calcification. With no carbonate in the media used in the calcification studies, we used stable isotope probing with C 13 O 2 to determine whether atmospheric CO 2 could be the source of these ions. The resultant crystals were significantly enriched in this heavy isotope, suggesting that extracellular CO 2 does indeed contribute to the mineral structure. The physiological adaptation of removing toxic Ca 2+ ions by calcification, while useful in numerous environments, would be particularly beneficial to bacteria in Ca 2+ -rich cave environments. Such activity may also create the initial crystal nucleation sites that contribute to the formation of secondary CaCO 3 deposits within caves.