Microbially Enhanced Carbon Capture and Storage by Mineral-Trapping and Solubility-Trapping

Growth of microorganisms in environments containing CO 2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO 2 (scCO 2 ) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO 2 . Analysis of 16S rRNA genes from scCO 2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO 2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO 2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO 2 , suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO 2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO 2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO 2 in the deep subsurface.

mentioning

confidence: 99%

Microbial Growth under Supercritical CO ₂

Peet

Freedman

Hernandez

et al. 2015

“…In engineered systems, microbially induced scale formation decreases the performance of a wide variety of processes, including membrane separations in water treatment and heat exchange efficiency in cooling towers (15,16). More recently, calcium carbonate biomineralization has also been explored as a novel biotechnology for the purpose of bioremediation and stabilization of porous structures, including soils, sediments, and construction materials (17)(18)(19)(20)(21).…”

mentioning

confidence: 99%

Spatial Patterns of Carbonate Biomineralization in Biofilms

Chopp

Russin

et al. 2015

dMicrobially catalyzed precipitation of carbonate minerals is an important process in diverse biological, geological, and engineered systems. However, the processes that regulate carbonate biomineralization and their impacts on biofilms are largely unexplored, mainly because of the inability of current methods to directly observe biomineralization within biofilms. Here, we present a method for in situ, real-time imaging of biomineralization in biofilms and use it to show that Pseudomonas aeruginosa biofilms produce morphologically distinct carbonate deposits that substantially modify biofilm structures. The patterns of carbonate biomineralization produced in situ were substantially different from those caused by accumulation of particles produced by abiotic precipitation. Contrary to the common expectation that mineral precipitation should occur at the biofilm surface, we found that biomineralization started at the base of the biofilm. The carbonate deposits grew over time, detaching biofilm-resident cells and deforming the biofilm morphology. These findings indicate that biomineralization is a general regulator of biofilm architecture and properties. Microbially induced carbonate precipitation represents an essential pathway for sequestration of large amounts of carbon in ancient and modern environments (1-5). Rock records reveal that Precambrian stromatolites formed as a consequence of trapping, binding, and precipitation of calcium carbonate by the growth and metabolism of microorganisms (2-4). Modern carbonate microbialites are found in a wide range of environments, including freshwater, oceans, hypersaline lakes, and soils (6, 7). Clinically, prolonged bacterial infection of indwelling urinary catheters leads to the formation of mineralized biofilms that can occlude the catheter lumen and cause serious complications (8-10). Some persistent infections of the lungs, particularly those associated with the genetic disorder primary ciliary dyskinesia, involve precipitation of calcium-rich stones or coatings (11)(12)(13)(14). In engineered systems, microbially induced scale formation decreases the performance of a wide variety of processes, including membrane separations in water treatment and heat exchange efficiency in cooling towers (15, 16). More recently, calcium carbonate biomineralization has also been explored as a novel biotechnology for the purpose of bioremediation and stabilization of porous structures, including soils, sediments, and construction materials (17-21).The microorganisms involved in carbonate biomineralization cover nearly all classes, including bacteria, algae, and fungi (22-27). It has been reported that more than 200 soil bacteria, including Pseudomonas spp., Bacillus subtilis, and Azotobacter spp., are capable of inducing calcium carbonate precipitation (5). Diverse microbial metabolisms, such as photosynthesis, sulfate reduction, and urea hydrolysis, can induce carbonate precipitation by significantly changing the saturation state of calcium carbonate (28,29). Microbial respiration p...

“…Bacterial mineralization of calcium carbonates has found applications in the remediation (fixation) of metalcontaminated soil and groundwater (87), atmospheric CO 2 sequestration (21,59), the strengthening and consolidation of soil and sand (14), the reduction of the porosity and/or permeability of geological formations (24,29), the protection and repair of concrete and cement structures (15,66), and the conservation of building stone and statuary (16,19,30,38,39,40,47,69,84,88,94). Recently, bacterial precipitation of fluorescent calcium carbonate, with potential applications as a filler in rubber, plastics, and stationery ink and as a fluorescent marker, has been reported (93).…”

mentioning

confidence: 99%

Influence of Substrate Mineralogy on Bacterial Mineralization of Calcium Carbonate: Implications for Stone Conservation

Rodríguez-Navarro

Jroundi

Schiro

et al. 2012

186

101

ABSTRACTThe influence of mineral substrate composition and structure on bacterial calcium carbonate productivity and polymorph selection was studied. Bacterial calcium carbonate precipitation occurred on calcitic (Iceland spar single crystals, marble, and porous limestone) and silicate (glass coverslips, porous sintered glass, and quartz sandstone) substrates following culturing in liquid medium (M-3P) inoculated with different types of bacteria (Myxococcus xanthus,Brevundimonas diminuta, and a carbonatogenic bacterial community isolated from porous calcarenite stone in a historical building) and direct application of sterile M-3P medium to limestone and sandstone with their own bacterial communities. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), and 2-dimensional XRD (2D-XRD) analyses revealed that abundant highly oriented calcite crystals formed homoepitaxially on the calcitic substrates, irrespective of the bacterial type. Conversely, scattered spheroidal vaterite entombing bacterial cells formed on the silicate substrates. These results show that carbonate phase selection is not strain specific and that under equal culture conditions, the substrate type is the overruling factor for calcium carbonate polymorph selection. Furthermore, carbonate productivity is strongly dependent on the mineralogy of the substrate. Calcitic substrates offer a higher affinity for bacterial attachment than silicate substrates, thereby fostering bacterial growth and metabolic activity, resulting in higher production of calcium carbonate cement. Bacterial calcite grows coherently over the calcitic substrate and is therefore more chemically and mechanically stable than metastable vaterite, which formed incoherently on the silicate substrates. The implications of these results for technological applications of bacterial carbonatogenesis, including building stone conservation, are discussed.