Article

Strain-specific ureolytic microbial calcium carbonate precipitation.

Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, B-9000 Ghent, Belgium.
Applied and Environmental Microbiology (Impact Factor: 3.68). 09/2003; 69(8):4901-9. DOI: 10.1128/AEM.69.8.4901-4909.2003
Source: PubMed

ABSTRACT During a study of ureolytic microbial calcium carbonate (CaCO(3)) precipitation by bacterial isolates collected from different environmental samples, morphological differences were observed in the large CaCO(3) crystal aggregates precipitated within bacterial colonies grown on agar. Based on these differences, 12 isolates were selected for further study. We hypothesized that the striking differences in crystal morphology were the result of different microbial species or, alternatively, differences in the functional attributes of the isolates selected. Sequencing of 16S rRNA genes showed that all of the isolates were phylogenetically closely related to the Bacillus sphaericus group. Urease gene diversity among the isolates was examined by using a novel application of PCR-denaturing gradient gel electrophoresis (DGGE). This approach revealed significant differences between the isolates. Moreover, for several isolates, multiple bands appeared on the DGGE gels, suggesting the apparent presence of different urease genes in these isolates. The substrate affinities (K(m)) and maximum hydrolysis rates (V(max)) of crude enzyme extracts differed considerably for the different strains. For certain isolates, the urease activity increased up to 10-fold in the presence of 30 mM calcium, and apparently this contributed to the characteristic crystal formation by these isolates. We show that strain-specific calcification occurred during ureolytic microbial carbonate precipitation. The specificity was mainly due to differences in urease expression and the response to calcium.

0 Bookmarks
 · 
79 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Calcium carbonate materials are frequently used in various industries and for diverse environmental engineering applications, such as water and wastewater treatment and reduction of soil acidity for agriculture. In this study, optimization of microbially induced calcium carbonate micro-particle production by Sporosarcina pasteurii ATCC 11859 was investigated with the response surface methodology (RSM). The natural calcium carbonate precipitation reaction is largely dependent on environmental factors and in the presence of microorganisms. Therefore, a central composite design (CCD) was employed to determine the different concentrations of urea, calcium chloride and nickel (II) nitrate to be investigated. The experimental CCD results were applied in a quadratic model to predict the optimum concentrations of these factors to maximize the production of calcium carbonate. The mathematical model determined that the optimum urea, calcium chloride and nickel (II) nitrate concentrations were 42.12 g/l, 6.93 g/l, and 0.071 g/l, respectively. Under these conditions, S. pasteurii growth and the calcium carbonate precipitation rates were 0.786 h−1 and 0.145 h−1, respectively. Also, at these optimum conditions, the urease activity was 3.4 U/ml, which was 2.5 times higher than the current calcium carbonate conditions described in the literature. The size of the calcium carbonate particles produced ranged from 0.1 μm to 10 μm in diameter.
    Ecological Engineering. 01/2014; 62:168–174.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Contamination by Cd is a significant environmental problem. Therefore, we examined Cd removal from an environmental perspective. Ureolysis-driven calcium carbonate precipitation has been proposed for use in geotechnical engineering for soil remediation applications. In this study, 55 calcite-forming bacterial strains were newly isolated from various environments. Biomineralization of Cd by calcite-forming bacteria was investigated in laboratory-scale experiments. A simple method was developed to determine the effectiveness of microbially induced calcite precipitation (MICP). Using this method, we determined the effectiveness of biomineralization for retarding the flow of crystal violet through a 25-mL column. When the selected bacteria were analyzed using an inductively coupled plasma optical emission spectrometer, high removal rates (99.95 %) of Cd were observed following incubation for 48 h. Samples of solids that formed in the reaction vessels were examined using a scanning electron microscope. The CdCO3 compounds primarily showed a spherical shape. The results of this study demonstrate that MICP-based sequestration of soluble heavy metals via coprecipitation with calcite may be useful for toxic heavy metal bioremediation.
    Applied biochemistry and biotechnology 12/2013; · 1.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Heterotrophic CaCO3-precipitating bacteria were isolated from biofilms on deteriorated ignimbrites, siliceous acidic rocks, from Morelia Cathedral (Mexico) and identified as Enterobacter cancerogenus (22e), Bacillus sp. (32a) and Bacillus subtilis (52g). In solid medium, 22e and 32a precipitated calcite and vaterite while 52g produced calcite. Urease activity was detected in these isolates and CaCO3 precipitation increased in the presence of urea in the liquid medium. In the presence of calcium, EPS production decreased in 22e and 32a and increased in 52g. Under laboratory conditions, ignimbrite colonization by these isolates only occurred in the presence of calcium and no CaCO3 was precipitated. Calcium may therefore be important for biofilm formation on stones. The importance of the type of stone, here a siliceous stone, on biological colonization is emphasized. This calcium effect has not been reported on calcareous materials. The importance of the effect of calcium on EPS production and biofilm formation is discussed in relation to other applications of CaCO3 precipitation by bacteria.
    Biofouling 04/2014; · 3.40 Impact Factor

Full-text (2 Sources)

View
18 Downloads
Available from
May 17, 2014