Carbonate biomineralization induced by soil bacterium Bacillus megaterium

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Scientific paper

Biogenic carbonates spawned from microbial activities are common occurrences in soils. Here, we investigate the carbonate biomineralization mediated by the bacterium Bacillus megaterium, a dominant strain separated from a loess profile in China. Upon completing bacterial cultivation, the ensuring products are centrifuged, and the resultant supernatant and the concentrated bacterial sludge as well as the un-separated culture are added separately into a Ca-CO3 containing solution for crystallization experiments. Results of XRD and SEM analysis indicate that calcite is the dominant mineral phase formed when the bacteria are present. When the supernatant alone is used, however, a significant portion of vaterite is also precipitated. Experimental results further reveal that the bacteria have a strong tendency to colonize the center area of the calcite {1 0 1¯ 4} faces. Observed crystal morphology suggests that the bacterial colony may promote the growth normal to each individual {1 0 1¯ 4} face of calcite when the cell concentration is high, but may retard it or even cause dissolution of the immediate substrate surfaces when the concentration is low. SEM images taken at earlier stages of the crystallization experiments demonstrate the nucleation of calcite on the bacterial cell walls but do not show obvious morphological changes on the nanometer- to submicron-sized nuclei. δ13C measurements unveil that the crystals grown in the presence of bacteria are further enriched in the heavy carbon isotope, implying that the bacterial metabolism may not be the carbon sources for the mineralization. Based upon these findings, we propose a mechanism for the B. megaterium mediated calcite mineralization and conclude that the whole process involves epi- and inter-cellular growth in the local microenvironments whose conditions may be controlled by cell sequestration and proton pumping during bacterial respiration.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Carbonate biomineralization induced by soil bacterium Bacillus megaterium does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Carbonate biomineralization induced by soil bacterium Bacillus megaterium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbonate biomineralization induced by soil bacterium Bacillus megaterium will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1314665

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.