ORCID Profile
0000-0002-6928-0448
Current Organisation
Curtin University
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Mineralogy and Crystallography | Inorganic Geochemistry | Geochemistry | Earth Sciences not elsewhere classified
Expanding Knowledge in the Earth Sciences | Expanding Knowledge in the Chemical Sciences |
Publisher: Springer Science and Business Media LLC
Date: 21-10-2021
DOI: 10.1038/S41598-021-00315-5
Abstract: Microbially induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications. There are chiefly two methods by which MICP is applied for field applications including biostimulation and bioaugmentation. Although bioaugmentation strategy using efficient ureolytic biocementing culture of Sporosarcina pasteurii is widely practiced, the impact of native ureolytic microbial communities (NUMC) on CaCO 3 mineralisation via S. pasteurii has not been explored. In this paper, we investigated the effect of different concentrations of NUMC on MICP kinetics and biomineral properties in the presence and absence of S. pasteurii. Kinetic analysis showed that the biocementation potential of S. pasteurii is sixfold higher than NUMC and is not significantly impacted even when the concentration of the NUMC is eight times higher. Micrographic results revealed a quick rate of CaCO 3 precipitation by S. pasteurii leading to generation of smaller CaCO 3 crystals (5–40 µm), while slow rate of CaCO 3 precipitation by NUMC led to creation of larger CaCO 3 crystals (35–100 µm). Mineralogical results showed the predominance of calcite phase in both sets. The outcome of current study is crucial for tailor-made applications of MICP.
Publisher: Frontiers Media SA
Date: 2013
Publisher: Elsevier BV
Date: 02-2012
Publisher: Elsevier BV
Date: 02-2016
Publisher: MDPI AG
Date: 15-12-2021
DOI: 10.3390/SU132413878
Abstract: Microbially Induced Calcium Carbonate Precipitation (MICP) is a natural biocementation that takes place in corals, stromatolites and beach rocks. In recent years, researchers have explored the emulation of this process as a sustainable alternative of engineered cement. Although the natural process is undoubtedly sustainable, its engineered variant deviates substantially from the natural process. In this paper, we investigate the environmental and economic performance of the engineered biocementation process vis-à-vis present manufacturing of calcium carbonate. SimaPro 8.0 software and the Ecoinvent V2.2 database were used for materials inputs and AUSLCI along with Cumulative Energy Demand 2.01 software were used for carbon footprint and eutrophication potential. Our results show that different metabolic pathways of MICP have considerably varying environmental impact. We observe that nature performs MICP sustainably at ambient conditions and geological time scales utilizing naturally occurring sources of carbon and calcium at micromoles concentrations. Due to the mandate on duration of construction projects, highly purified reactants in a high concentration are used in the engineered process. This has a negative environmental impact. We conclude that the sustainability of engineered MICP is directly impacted by the metabolic pathway of bacteria as well as the purity of the input chemicals. A few biotic processes are superior to the present industrial process for manufacturing calcium carbonate if ingredients of laboratory grade purity are replaced by industrial grade products. A bigger idend can be obtained by introducing industry by-products as nutrients. The results of this study help to direct future research for developing sustainable biocement for the construction industry.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Frontiers Media SA
Date: 26-06-2014
Publisher: Springer Science and Business Media LLC
Date: 05-02-2015
DOI: 10.1007/S12010-015-1524-3
Abstract: Microbially induced calcium carbonate precipitation is an immensely growing technology for restoration and remediation of building materials. The investigation on role of exopolymeric substances and biofilms in microbially induced calcium carbonate precipitation suggested that these exopolymeric materials play major role in carbonate precipitation in Bacillus megaterium SS3 along with enzymes urease and carbonic anhydrase. The concentration of EPS directly affects the precipitation of carbonate precipitates which might be due to capturing of Ca(2+) ions by acting as nucleation site. Components of the media and presence of calcium also play crucial role in production of exopolymeric substances along with affecting the morphology of carbonate precipitates.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2020
Publisher: Wiley
Date: 19-05-2016
DOI: 10.1002/APJ.2014
Publisher: Elsevier BV
Date: 12-2021
Publisher: Springer Science and Business Media LLC
Date: 18-04-2022
DOI: 10.1007/S11440-022-01536-2
Abstract: Increased frequency of extreme weather events has made the conservation of riverbanks and coastlines a global concern. Soil stabilisation via microbially induced calcite precipitation (MICP) is one of the most eco-suitable candidates for improving resilience against erosion. In this study, the erosion characteristics of soil treated with various levels of biocementation are investigated. The s les were subjected to hydraulic flow in both tangential and perpendicular directions in a flume to simulate riverbank and coastal situations. Soil mass loss, eroded volume, and cumulative erosion rates of the treated soil against the applied hydraulic energy density have been reported. Post erosion exposure, the residual soil has been assessed for its properties using needle penetration resistance, precipitated calcium carbonate content and microstructure. It was observed that soil erosion declined exponentially with the increase in calcium carbonate content against the perpendicular waves. However, biocementation leads to brittle fracture beyond a threshold, limiting its efficacy, especially against the tangential waves. Additional composite treatment with a biopolymer was found to improve the resilience of the soil specimens against erosion. The composite treatment required half of the quantity of the biocementing reagents in comparison to the equally erosion-resistant plain biocemented s le. Therefore, stoichiometrically the composite treatment is likely to yield 50% lesser ammonia than plain biocement treatment. This investigation unravels a promising soil conservation technique via the composite effect of biocement and biopolymer.
Publisher: American Society of Civil Engineers (ASCE)
Date: 2022
Publisher: Elsevier BV
Date: 09-2017
Publisher: Oxford University Press (OUP)
Date: 12-2013
DOI: 10.1007/S10295-013-1338-7
Abstract: Evidence of bacterial involvement in precipitation of calcium carbonates has brought a revolution in the field of applied microbiology, geotechnical sciences, environmental and civil engineering with its marked success in restoration of various building materials. For applications of these calcite binder-producing bacterial cultures, different expensive carrier materials have been used but their high costs have come in the way of their successful commercialization. In the present study, we have explored the potential of cheap industrial by-product fly ash as a carrier material for bacterial cells and investigated the viability of calcifying bacterial isolates: Bacillus megaterium, Bacillus cereus, and Lysinibacillus fusiformis in fly ash carrier at varying temperatures and moisture conditions along with biomineralization efficacy of these formulations. We used laser scanning confocal microscopy to analyze the viability of bacteria by florescent dye 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) along with the plate count method. Results revealed that fly ash successfully served as an effective carrier material and bacterial formulations stored at 4 °C provided longer shelf life than those stored at higher temperatures. Up to 106 cfu/g was found to sustain in all formulations at 4 °C compared to 104-105 cfu/g in case of higher temperatures up to 1 year. For 4 °C, higher moistures (50 %) were found to provide better survivability while for higher temperatures, lower moistures (30 %) favored higher viability. The biomineralization capability of fresh and formulated bacterial cells was compared on the basis of precipitation of carbonates and it was found that carbonate precipitation efficacy of formulated bacterial cells was comparable to fresh bacterial cells.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2023
Publisher: Elsevier BV
Date: 10-2019
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 10-2017
Publisher: Thomas Telford Ltd.
Date: 06-2018
Abstract: The Australian road network is nearly a million kilometres long, of which 83% can be classified as rural roads. The size and remote nature of Australia's road network pose unique challenges in terms of asset monitoring and maintenance costs. Cement stabilisation is a practice commonly used to improve durability and reduce inspection and repair costs. However, due to the sheer length of the road network, a huge quantity of cement is consumed in stabilisation work, making this practice unsustainable. This paper explores a sustainable alternative through augmentation of the traditional cement-based stabilisation with microbial carbonate precipitation. The calcium carbonate crystals formed within the s les were investigated by scanning electron microscopy and X-ray diffraction. Bulk mechanical properties were characterised through unconfined compressive strength (UCS) testing and the digital image correlation technique was utilised during UCS testing to extract more refined information such as local deformation and strain build-up. The mechanical properties at the microscopic scale were characterised through nanoindentation testing. The results show that microbial precipitation is able to increase the strength of cement-stabilised and road base materials significantly and can considerably improve the technological, economic and social sustainability of Australian road bases.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Oxford University Press (OUP)
Date: 11-2016
DOI: 10.1007/S10295-016-1835-6
Abstract: Microbial carbonate precipitation has emerged as a promising technology for remediation and restoration of concrete structures. Deterioration of reinforced concrete structures in marine environments is a major concern due to chloride-induced corrosion. In the current study, halophilic bacteria Exiguobacterium mexicanum was isolated from sea water and tested for biomineralization potential under different salt stress conditions. The growth, urease and carbonic anhydrase production significantly increased under salt stress conditions. Maximum calcium carbonate precipitation was recorded at 5 % NaCl concentration. Application of E. mexicanum on concrete specimens significantly increased the compressive strength (23.5 %) and reduced water absorption about five times under 5 % salt stress conditions compared to control specimens. SEM and XRD analysis of bacterial-treated concrete specimens confirmed the precipitation of calcite. The present study results support the potential of this technology for improving the strength and durability properties of building structures in marine environments.
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 06-2017
Publisher: Frontiers Media SA
Date: 11-07-2017
Publisher: Frontiers Media SA
Date: 02-02-2018
Publisher: Springer Science and Business Media LLC
Date: 15-10-2023
Publisher: Public Library of Science (PLoS)
Date: 12-07-2021
DOI: 10.1371/JOURNAL.PONE.0254536
Abstract: Microbially induced calcium carbonate precipitation (MICP) process utilising the biogeochemical reactions for low energy cementation has recently emerged as a potential technology for numerous engineering applications. The design and development of an efficient MICP process depends upon several physicochemical and biological variables amongst which the initial bacterial cell concentration is a major factor. The goal of this study is to assess the impact of initial bacterial cell concentration on ureolysis and carbonate precipitation kinetics along with its influence on the calcium carbonate crystal properties as all these factors determine the efficacy of this process for specific engineering applications. We have also investigated the role of subsequent cell recharge in calcium carbonate precipitation kinetics for the first time. Experimental results showed that the kinetics of ureolysis and calcium carbonate precipitation are well-fitted by an exponential logistic equation for cell concentrations between optical density range of 0.1 OD to 0.4 OD. This equation is highly applicable for designing the optimal processes for microbially cemented soil stabilization applications using native or augmented bacterial cultures. Multiple recharge kinetics study revealed that the addition of fresh bacterial cells is an essential step to keep the fast rate of precipitation, as desirable in certain applications. Our results of calcium carbonate crystal morphology and mineralogy via scanning electron micrography, energy dispersive X-ray spectroscopy and X-ray diffraction analysis exhibited a notable impact of cell number and extracellular urease concentration on the properties of carbonate crystals. Lower cell numbers led to formation of larger crystals compared to high cell numbers and these crystals transform from vaterite phase to the calcite phase over time. This study has demonstrated the significance of kinetic models for designing large-scale MICP applications.
Publisher: Frontiers Media SA
Date: 20-01-2022
DOI: 10.3389/FMATS.2021.681850
Abstract: Bacterial biopolymers produced extracellularly due to microbial metabolic activities have gained considerable interest in various engineering applications. The major advantages of bacterial biopolymers is their in-situ production and low water solubility, eliminating the requirement for mixing in granular substrates such as soils. These properties make them highly desirable and preferable to manufactured biopolymers. But for any engineering applications, it is crucial to understand the mechanical properties of these materials, which have been less explored. This investigation is the first attempt to quantify the nano and macro mechanical properties of in-situ bacterial biopolymer dextran produced by bacterial culture Leucononstoc mesenteroids . The fundamental mechanism of bacterial biopolymer-based cementation has been revealed through their morphographic and nanomechanical testing via atomic force microscopy, nanoindentation and scanning electron micrographs. The effect of bacterially produced biopolymers and commercial biopolymers on the macro-mechanical properties of soils was then investigated via needle penetration tests. In-situ biopolymers were found to be highly effective in stabilizing soils with comparable mechanical properties as commercial biopolymers. This study has demonstrated novel methods for testing in situ polymers and opened up the channels for their applications in numerous subsurface as well as surface applications.
Publisher: Springer Science and Business Media LLC
Date: 23-06-2013
DOI: 10.1007/S11274-013-1408-Z
Abstract: Microbially induced calcium carbonate precipitation is a biomineralization process that has various applications in remediation and restoration of range of building materials. In the present study, calcifying bacteria, Bacillus megaterium SS3 isolated from calcareous soil was applied as biosealant to enhance the durability of low energy, green building materials (soil-cement blocks). This bacterial isolate produced high amounts of urease, carbonic anhydrase, extra polymeric substances and biofilm. The calcium carbonate polymorphs produced by B. megaterium SS3 were analyzed by scanning electron microscopy, confocal laser scanning microscopy, X-ray diffraction and Fourier transmission infra red spectroscopy. These results suggested that calcite is the most predominant carbonate formed by this bacteria followed by vaterite. Application of B. megaterium SS3 as biogenic surface treatment led to 40 % decrease in water absorption, 31 % decrease in porosity and 18 % increase in compressive strength of low energy building materials. From the present investigation, it is clear that surface treatment of building materials by B. megaterium SS3 is very effective and eco friendly way of biodeposition of coherent carbonates that enhances the durability of building materials.
Publisher: Springer Science and Business Media LLC
Date: 10-01-2014
DOI: 10.1007/S12010-013-0694-0
Abstract: The investigation on the synergistic role of urease (UA) and carbonic anhydrase (CA) in biomineralization of calcium carbonate in Bacillus megaterium suggested that the precipitation of CaCO3 is significantly faster in bacterial culture than in crude enzyme solutions. Calcite precipitation is significantly reduced when both the enzymes are inhibited in comparison with those of the in idual enzyme inhibitions indicating that both UA and CA are crucial for efficient mineralization. Carbonic anhydrase plays a role in hydrating carbon dioxide to bicarbonate, while UA aids in maintaining the alkaline pH that promotes calcification process.
Start Date: 11-2022
End Date: 11-2025
Amount: $485,000.00
Funder: Australian Research Council
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