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Carbonate Mineral Formation under the Influence of Limestone-Colonizing Actinobacteria: Morphology and Polymorphism.

Cao C, Jiang J, Sun H, Huang Y, Tao F, Lian B - Front Microbiol (2016)

Bottom Line: Mineralogical analyses showed that hexagonal prism calcite was only observed in the sub-surfaces of the mycelium pellets, which is a novel morphology mediated by microbes.Our analyses suggested that the effects of mycelium pellets as a molecular template almost gained an advantage over SMP both in crystal nucleation and growth, having nothing to do with biological activity.It is thereby convinced that lithophilous actinobacteria, S. luteogriseus DHS C014, owing to its advantageous genetic metabolism and filamentous structure, showed good biomineralization abilities, maybe it would have geoactive potential for biogenic carbonate in local microenvironments.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of SciencesGuiyang, China; Institute of Geochemistry, University of Chinese Academy of SciencesBeijing, China; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal UniversityXuzhou, China.

ABSTRACT
Microorganisms and their biomineralization processes are widespread in almost every environment on earth. In this work, Streptomyces luteogriseus DHS C014, a dominant lithophilous actinobacteria isolated from microbial mats on limestone rocks, was used to investigate its potential biomineralization to allow a better understanding of bacterial contributions to carbonate mineralization in nature. The ammonium carbonate free-drift method was used with mycelium pellets, culture supernatant, and spent culture of the strain. Mineralogical analyses showed that hexagonal prism calcite was only observed in the sub-surfaces of the mycelium pellets, which is a novel morphology mediated by microbes. Hemispheroidal vaterite appeared in the presence of spent culture, mainly because of the effects of soluble microbial products (SMP) during mineralization. When using the culture supernatant, doughnut-like vaterite was favored by actinobacterial mycelia, which has not yet been captured in previous studies. Our analyses suggested that the effects of mycelium pellets as a molecular template almost gained an advantage over SMP both in crystal nucleation and growth, having nothing to do with biological activity. It is thereby convinced that lithophilous actinobacteria, S. luteogriseus DHS C014, owing to its advantageous genetic metabolism and filamentous structure, showed good biomineralization abilities, maybe it would have geoactive potential for biogenic carbonate in local microenvironments.

No MeSH data available.


Related in: MedlinePlus

Morphologies of biominerals in SM treatments. Panel (A) Showing vaterite with spherical cone morphology and EDS spectrum obtained from the asterisked site (the Au peak was the result of ion sputtering used before SEM examination); (B) showing crystal details of the boxed area on Panel (A); (C) showing bottom details of the biominerals.
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Figure 8: Morphologies of biominerals in SM treatments. Panel (A) Showing vaterite with spherical cone morphology and EDS spectrum obtained from the asterisked site (the Au peak was the result of ion sputtering used before SEM examination); (B) showing crystal details of the boxed area on Panel (A); (C) showing bottom details of the biominerals.

Mentions: In SM treatments, vaterite crystals were characteristically hemispheroidal in the presence of spent medium (Figure 8A). Several radial flaws appeared on the top of the hemispheroidal crystal (Figure 8B). EDS data identified Ca, C, and O as major elements in the spherical cone crystals (Figure 8B), in agreement with XRD and FTIR data. On the other hand, the bottom of the crystals developed into a fibro-radial structure with slight central invagination (Figure 8C). Hemispheroidal vaterite crystals in SM treatments were different from those seen in previous studies in mesocrystals and their reorganization into larger crystals. In the presence of a super-solution of Bacillus megaterium, spherulitic vaterite with a hollow core seemed to be composed of six identical cloves (Table 1b2; Lian et al., 2006). Vaterite spherulites with smoother surfaces (Table 1d2) were induced during the incubation of M. xanthus at 28°C with constant shaking (Rodriguez-Navarro et al., 2007). Whereas, vaterite spheres with a hole on their surfaces (Table 1e2) were mediated by Proteus mirabilis growing in a reaction solution (0.1 mol L−1 CaCl2 and 0.2 mol L−1 urea) at 27°C for 5 days (Chen et al., 2008). During the reorganization process, small aggregated 20–30 nm nanoparticles resulted in rough mesocrystal surfaces to develop. The crystal surfaces perhaps became covered with holes due to specific protein binding, and subsequent inhibition of crystal growth (Mann et al., 2007; Decho, 2010). Similarly, Rodriguez-Navarro concluded that surfaces of these biominerals were very rough in the presence of aggregates of nanometer-sized building blocks (Rodriguez-Navarro et al., 2007, 2012). These results pertinent to the morphology and polymorphism of biominerals suggested that mineralization mediated by microbes, to some extent, was strain-specific and associated with various biomacromolecular templates.


Carbonate Mineral Formation under the Influence of Limestone-Colonizing Actinobacteria: Morphology and Polymorphism.

Cao C, Jiang J, Sun H, Huang Y, Tao F, Lian B - Front Microbiol (2016)

Morphologies of biominerals in SM treatments. Panel (A) Showing vaterite with spherical cone morphology and EDS spectrum obtained from the asterisked site (the Au peak was the result of ion sputtering used before SEM examination); (B) showing crystal details of the boxed area on Panel (A); (C) showing bottom details of the biominerals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834437&req=5

Figure 8: Morphologies of biominerals in SM treatments. Panel (A) Showing vaterite with spherical cone morphology and EDS spectrum obtained from the asterisked site (the Au peak was the result of ion sputtering used before SEM examination); (B) showing crystal details of the boxed area on Panel (A); (C) showing bottom details of the biominerals.
Mentions: In SM treatments, vaterite crystals were characteristically hemispheroidal in the presence of spent medium (Figure 8A). Several radial flaws appeared on the top of the hemispheroidal crystal (Figure 8B). EDS data identified Ca, C, and O as major elements in the spherical cone crystals (Figure 8B), in agreement with XRD and FTIR data. On the other hand, the bottom of the crystals developed into a fibro-radial structure with slight central invagination (Figure 8C). Hemispheroidal vaterite crystals in SM treatments were different from those seen in previous studies in mesocrystals and their reorganization into larger crystals. In the presence of a super-solution of Bacillus megaterium, spherulitic vaterite with a hollow core seemed to be composed of six identical cloves (Table 1b2; Lian et al., 2006). Vaterite spherulites with smoother surfaces (Table 1d2) were induced during the incubation of M. xanthus at 28°C with constant shaking (Rodriguez-Navarro et al., 2007). Whereas, vaterite spheres with a hole on their surfaces (Table 1e2) were mediated by Proteus mirabilis growing in a reaction solution (0.1 mol L−1 CaCl2 and 0.2 mol L−1 urea) at 27°C for 5 days (Chen et al., 2008). During the reorganization process, small aggregated 20–30 nm nanoparticles resulted in rough mesocrystal surfaces to develop. The crystal surfaces perhaps became covered with holes due to specific protein binding, and subsequent inhibition of crystal growth (Mann et al., 2007; Decho, 2010). Similarly, Rodriguez-Navarro concluded that surfaces of these biominerals were very rough in the presence of aggregates of nanometer-sized building blocks (Rodriguez-Navarro et al., 2007, 2012). These results pertinent to the morphology and polymorphism of biominerals suggested that mineralization mediated by microbes, to some extent, was strain-specific and associated with various biomacromolecular templates.

Bottom Line: Mineralogical analyses showed that hexagonal prism calcite was only observed in the sub-surfaces of the mycelium pellets, which is a novel morphology mediated by microbes.Our analyses suggested that the effects of mycelium pellets as a molecular template almost gained an advantage over SMP both in crystal nucleation and growth, having nothing to do with biological activity.It is thereby convinced that lithophilous actinobacteria, S. luteogriseus DHS C014, owing to its advantageous genetic metabolism and filamentous structure, showed good biomineralization abilities, maybe it would have geoactive potential for biogenic carbonate in local microenvironments.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of SciencesGuiyang, China; Institute of Geochemistry, University of Chinese Academy of SciencesBeijing, China; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal UniversityXuzhou, China.

ABSTRACT
Microorganisms and their biomineralization processes are widespread in almost every environment on earth. In this work, Streptomyces luteogriseus DHS C014, a dominant lithophilous actinobacteria isolated from microbial mats on limestone rocks, was used to investigate its potential biomineralization to allow a better understanding of bacterial contributions to carbonate mineralization in nature. The ammonium carbonate free-drift method was used with mycelium pellets, culture supernatant, and spent culture of the strain. Mineralogical analyses showed that hexagonal prism calcite was only observed in the sub-surfaces of the mycelium pellets, which is a novel morphology mediated by microbes. Hemispheroidal vaterite appeared in the presence of spent culture, mainly because of the effects of soluble microbial products (SMP) during mineralization. When using the culture supernatant, doughnut-like vaterite was favored by actinobacterial mycelia, which has not yet been captured in previous studies. Our analyses suggested that the effects of mycelium pellets as a molecular template almost gained an advantage over SMP both in crystal nucleation and growth, having nothing to do with biological activity. It is thereby convinced that lithophilous actinobacteria, S. luteogriseus DHS C014, owing to its advantageous genetic metabolism and filamentous structure, showed good biomineralization abilities, maybe it would have geoactive potential for biogenic carbonate in local microenvironments.

No MeSH data available.


Related in: MedlinePlus