Eryürük K. Effect of cell density on decrease in hydraulic conductivity by microbial calcite precipitation.
AMB Express 2022;
12:104. [PMID:
35939240 PMCID:
PMC9360383 DOI:
10.1186/s13568-022-01448-0]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 08/03/2022] [Indexed: 11/21/2022] Open
Abstract
The effect of number of cells deposited on decrease in hydraulic conductivity of porous media using CaCO3 precipitation induced by Sporosarcina pasteurii (ATCC 11,859) was examined in columns packed with glass beads in the range of 0.25 mm and 3 mm in diameter. After resting Sporosarcina pasteurii cells were introduced into the columns, a precipitation solution, which consisted of 500 mM CaCl2 and 500 mM urea, was introduced under continuous flow conditions. It was shown that hydraulic conductivity was decreased by formation of microbially induced CaCO3 precipitation from between 8.37 * 10−1 and 6.73 * 10−2 cm/s to between 3.69 * 10−1 and 1.01 * 10−2 cm/s. The lowest hydraulic conductivity was achieved in porous medium consisting of the smallest glass beads (0.25 mm in diameter) using the highest density of cell suspension (OD600 2.25). The number of the deposited cells differed depending on the glass bead size of the columns. According to the experiments, 7 * 10−9 g CaCO3 was produced by a single resting cell. The urease activity, which led CaCO3 precipitation, depended on presence of high number of cells deposited in the column because the nutrients were not included in the precipitation solution and consequently, the amount of CaCO3 precipitated was proportional with the cell number in the column. A mathematical model was also developed to investigate the experimental results, and statistical analysis was also performed.
Sporosarcina pasteurii, which is an ecologically friendly bacterium for environmental biotechnology, produces urease to form CaCO3 precipitation
CaCO3 precipitation decreases the hydraulic conductivity of porous media
The urease activity depends on the presence of high number of Sporosarcina pasteurii
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