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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

Schematic diagram of the experimental procedure.
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Figure 2: Schematic diagram of the experimental procedure.

Mentions: The strain was inoculated in 500 mL Erlenmeyer flasks containing 100 mL malt extract-glucose-yeast extract-peptone (MGYP) medium that consisted of: malt extract 0.3%, glucose 1%, yeast extract 0.3%, and peptone 0.5% (Rautaray et al., 2004). After adjusting the pH of the medium to 7.2 (6.9 after autoclave treatment), the cultures were incubated under continuous shaking on a rotary shaker (180 rpm) at 28°C for about 120 h, until microbial cells reached their late exponential phase. Mycelium pellets were harvested by centrifugation at 2000 rpm for 15 min at 4°C. Biological additives used in this study included: (i) Fresh medium (FM, as controls); (ii) Mycelium pellets (MP, mycelium pellets harvested by centrifugation were washed and re-suspended with sterile distilled water); (iii) Culture supernatant (CS, without mycelium pellets but including small mycelium fragments and other residues); (iv) Spent medium (SM, the culture supernatant was further filtered with a 0.22 μm sterilized membrane to eliminate mycelium fragments and other residues). The general procedure is shown in Figure 2.


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)

Schematic diagram of the experimental procedure.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: Schematic diagram of the experimental procedure.
Mentions: The strain was inoculated in 500 mL Erlenmeyer flasks containing 100 mL malt extract-glucose-yeast extract-peptone (MGYP) medium that consisted of: malt extract 0.3%, glucose 1%, yeast extract 0.3%, and peptone 0.5% (Rautaray et al., 2004). After adjusting the pH of the medium to 7.2 (6.9 after autoclave treatment), the cultures were incubated under continuous shaking on a rotary shaker (180 rpm) at 28°C for about 120 h, until microbial cells reached their late exponential phase. Mycelium pellets were harvested by centrifugation at 2000 rpm for 15 min at 4°C. Biological additives used in this study included: (i) Fresh medium (FM, as controls); (ii) Mycelium pellets (MP, mycelium pellets harvested by centrifugation were washed and re-suspended with sterile distilled water); (iii) Culture supernatant (CS, without mycelium pellets but including small mycelium fragments and other residues); (iv) Spent medium (SM, the culture supernatant was further filtered with a 0.22 μm sterilized membrane to eliminate mycelium fragments and other residues). The general procedure is shown in Figure 2.

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