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Scientific Reports Oct 2021Microbially induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications. There are chiefly two...
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 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 precipitation by S. pasteurii leading to generation of smaller CaCO crystals (5-40 µm), while slow rate of CaCO precipitation by NUMC led to creation of larger CaCO 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.
Topics: Calcium Carbonate; Chemical Precipitation; Crystallization; Kinetics; Microbiota; Sporosarcina
PubMed: 34675302
DOI: 10.1038/s41598-021-00315-5 -
Journal of Microbiology and... Mar 2016Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete,...
Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete, bioremediation, and long-term storage of CO2. CCP-capable bacteria, two Bacillus strains (JH3 and JH7) and one Sporosarcina strain (HYO08), were isolated from two samples of concrete and characterized phylogenetically. Calcium carbonate crystals precipitated by the three strains were morphologically distinct according to field emission scanning electron microscopy. Energy dispersive X-ray spectrometry mapping confirmed biomineralization via extracellular calcium carbonate production. The three strains differed in their physiological characteristics: growth at alkali pH and high NaCl concentrations, and urease activity. Sporosarcina sp. HYO08 and Bacillus sp. JH7 were more alkali- and halotolerant, respectively. Analysis of the community from the same concrete samples using barcoded pyrosequencing revealed that the relative abundance of Bacillus and Sporosarcina species was low, which indicated low culturability of other dominant bacteria. This study suggests that calcium carbonate crystals with different properties can be produced by various CCP-capable strains, and other novel isolates await discovery.
Topics: Bacillus; Bacteria; Calcium Carbonate; Chemical Precipitation; Construction Materials; Molecular Sequence Data; Phylogeny; Sporosarcina
PubMed: 26699752
DOI: 10.4014/jmb.1511.11008 -
Molecules (Basel, Switzerland) Sep 2020Antarctic regions are characterized by low temperatures and strong UV radiation. This harsh environment is inhabited by psychrophilic and psychrotolerant organisms,...
Antarctic regions are characterized by low temperatures and strong UV radiation. This harsh environment is inhabited by psychrophilic and psychrotolerant organisms, which have developed several adaptive features. In this study, we analyzed two Antarctic bacterial strains, sp. ANT_H30 and sp. ANT_H53B. The physiological analysis of these strains revealed their potential to produce various biotechnologically valuable secondary metabolites, including surfactants, siderophores, and orange pigments. The genomic characterization of ANT_H30 and ANT_H53B allowed the identification of genes responsible for the production of carotenoids and the in silico reconstruction of the pigment biosynthesis pathways. The complex manual annotation of the bacterial genomes revealed the metabolic potential to degrade a wide variety of compounds, including xenobiotics and waste materials. Carotenoids produced by these bacteria were analyzed chromatographically, and we proved their activity as scavengers of free radicals. The quantity of crude carotenoid extracts produced at two temperatures using various media was also determined. This was a step toward the optimization of carotenoid production by Antarctic bacteria on a larger scale.
Topics: Carotenoids; Genome, Bacterial; Genomics; Multigene Family; Phylogeny; Planococcus Bacteria; Rhodococcus
PubMed: 32977394
DOI: 10.3390/molecules25194357 -
Biology Letters 2013Specific immune priming enables an induced immune response upon repeated pathogen encounter. As a functional analogue to vertebrate immune memory, such adaptive...
Specific immune priming enables an induced immune response upon repeated pathogen encounter. As a functional analogue to vertebrate immune memory, such adaptive plasticity has been described, for instance, in insects and crustaceans. However, towards the base of the metazoan tree our knowledge about the existence of specific immune priming becomes scattered. Here, we exposed the invasive ctenophore Mnemiopsis leidyi repeatedly to two different bacterial epitopes (Gram-positive or -negative) and measured gene expression. Ctenophores experienced either the same bacterial epitope twice (homologous treatments) or different bacterial epitopes (heterologous treatments). Our results demonstrate that immune gene expression depends on earlier bacterial exposure. We detected significantly different expression upon heterologous compared with homologous bacterial treatment at three immune activator and effector genes. This is the first experimental evidence for specific immune priming in Ctenophora and generally in non-bilaterian animals, hereby adding to our growing notion of plasticity in innate immune systems across all animal phyla.
Topics: Animals; Bacterial Infections; Ctenophora; DNA Primers; Epitopes; Expressed Sequence Tags; Gene Expression Profiling; Gene Expression Regulation; Immune System; Listonella; Planococcus Bacteria; Real-Time Polymerase Chain Reaction
PubMed: 24257875
DOI: 10.1098/rsbl.2013.0864 -
Journal of Visualized Experiments : JoVE Apr 2016The particular bacterium under investigation here (S. pasteurii) is unique in its ability, under the right conditions, to induce the hydrolysis of urea (ureolysis) in...
The particular bacterium under investigation here (S. pasteurii) is unique in its ability, under the right conditions, to induce the hydrolysis of urea (ureolysis) in naturally occurring environments through secretion of an enzyme urease. This process of ureolysis, through a chain of chemical reactions, leads to the formation of calcium carbonate precipitates. This is known as Microbiologically Induced Calcite Precipitation (MICP). The proper culture protocols for MICP are detailed here. Finally, visualization experiments under different modes of microscopy were performed to understand various aspects of the precipitation process. Techniques like optical microscopy, Scanning Electron Microscopy (SEM) and X-Ray Photo-electron Spectroscopy (XPS) were employed to chemically characterize the end-product. Further, the ability of these precipitates to clog pores inside a natural porous medium was demonstrated through a qualitative experiment where sponge bars were used to mimic a pore-network with a range of length scales. A sponge bar dipped in the culture medium containing the bacterial cells hardens due to the clogging of its pores resulting from the continuous process of chemical precipitation. This hardened sponge bar exhibits superior strength when compared to a control sponge bar which becomes compressed and squeezed under the action of an applied external load, while the hardened bar is able to support the same weight with little deformation.
Topics: Calcium Carbonate; Chemical Precipitation; Sporosarcina; Urea; Urease
PubMed: 27167458
DOI: 10.3791/53253 -
PloS One 2019Microbially induced calcium carbonate precipitation (MICP) is a potential method for improvement of soil. A laboratory study was conducted to investigate the influence...
Microbially induced calcium carbonate precipitation (MICP) is a potential method for improvement of soil. A laboratory study was conducted to investigate the influence of temperatures for soil improvement by MICP. The ureolytic activity experiments, MICP experiments in aqueous solution and sand column using Sporosarcina pasteurii were conducted at different temperatures(10, 15, 20, 25 and 30°C). The results showed there were microbially induced CaCO3 precipitation at all the temperatures from 10 to 30°C. The results of ureolytic activity experiments showed that the bacterial had higher ureolytic activity at high temperatures within the early 20 hours, however, the ureolytic activity at higher temperatures decreased more quickly than at lower temperatures. The results of MICP experiments in aqueous solution and sand column were consistent with tests of ureolytic activity. Within 20 to 50 hours of the start of the test, more CaCO3 precipitation was precipitated at higher temperature, subsequently, the precipitation rate of all experiments decreased, and the higher the temperature, the faster the precipitation rate dropped. The final precipitation amount of CaCO3 in aqueous solution and sand column tests at 10 °C was 92% and 37% higher than that at 30 °C. The maximum unconfined compressive strength of MICP treated sand column at 10 °C was 135% higher than that at 30 °C. The final treatment effect of MICP at lower temperature was better than that at high temperature within the temperature range studied. The reason for better treatment effect at lower temperatures was due to the longer retention time of ureolytic activity of bacteria at lower temperatures.
Topics: Calcium Carbonate; Chemical Precipitation; Soil Microbiology; Sporosarcina; Temperature; Urea; Water
PubMed: 31211807
DOI: 10.1371/journal.pone.0218396 -
Scientific Reports Jun 2015The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP...
The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP 65.8(T), S. aureus ATCC 25923 and S. epidermidis ATCC 14990(T), was investigated. We demonstrate that exposing the bacteria to an EMF induced permeability in the bacterial membranes of all strains studied, as confirmed directly by transmission electron microscopy (TEM), and indirectly via the propidium iodide assay and the uptake of silica nanospheres. The cells remained permeable for at least nine minutes after EMF exposure. It was shown that all strains internalized 23.5 nm nanospheres, whereas the internalization of the 46.3 nm nanospheres differed amongst the bacterial strains (S. epidermidis ATCC 14990(T) ~ 0%; Staphylococcus aureus CIP 65.8(T) S. aureus ATCC 25923, ~40%; Planococcus maritimus KMM 3738, ~ 80%). Cell viability experiments indicated that up to 84% of the cells exposed to the EMF remained viable. The morphology of the bacterial cells was not altered, as inferred from the scanning electron micrographs, however traces of leaked cytosolic fluids from the EMF exposed cells could be detected. EMF-induced permeabilization may represent an innovative, alternative cell permeability technique for applications in biomedical engineering, cell drug delivery and gene therapy.
Topics: Biological Transport; Cell Membrane Permeability; Electromagnetic Fields; Electromagnetic Radiation; Microbial Viability; Microscopy, Electron, Transmission; Nanospheres; Particle Size; Planococcus Bacteria; Propidium; Silicon Dioxide; Staphylococcus aureus; Staphylococcus epidermidis
PubMed: 26077933
DOI: 10.1038/srep10980 -
Polish Journal of Microbiology 2016Naproxen is a one of the most popular non-steroidal anti-inflammatory drugs (NSAIDs) entering the environment as a result of high consumption. For this reason, there is...
Naproxen is a one of the most popular non-steroidal anti-inflammatory drugs (NSAIDs) entering the environment as a result of high consumption. For this reason, there is an emerging need to recognize mechanisms of its degradation and enzymes engaged in this process. Planococcus sp. S5 is a gram positive strain able to degrade naproxen in monosubstrate culture (27%). However, naproxen is not a sufficient growth substrate for this strain. In the presence of benzoate, 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid or vanillic acid as growth substrates, the degradation of 21.5%, 71.71%, 14.75% and 8.16% of naproxen was observed respectively. It was shown that the activity of monooxygenase, hydroxyquinol 1,2-dioxygenase, protocatechuate 3,4-dioxygenase and protocatechuate 4,5-dioxyegnase in strain S5 was induced after growth of the strain with naproxen and 4-hydroxybenzoate. Moreover, in the presence of naproxen activity of gentisate 1,2-dioxygenase, enzyme engaged in 4-hydroxybenzoate metabolism, was completely inhibited. The obtained results suggest that monooxygenase and hydroxyquinol 1,2-dioxygenase are the main enzymes in naproxen degradation by Planococcus sp. S5.
Topics: Anti-Inflammatory Agents, Non-Steroidal; Bacterial Proteins; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Naproxen; Planococcus Bacteria; Water Pollutants, Chemical
PubMed: 28517919
DOI: No ID Found -
Biomedical and Environmental Sciences :... Feb 2016Cr(VI) removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for...
OBJECTIVE
Cr(VI) removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr(VI) bioremediation from sediment samples and to optimize parameters of biodegradation.
METHODS
Strains with the ability to tolerate Cr(VI) were obtained by serial dilution and spread plate methods and characterized by morphology, 16S rDNA identification, and phylogenetic analysis. Cr(VI) was determined using the 1,5-diphenylcarbazide method, and the optimum pH and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results.
RESULTS
Fifty-five strains were obtained, and one strain (Sporosarcina saromensis M52; patent application number: 201410819443.3) having the ability to tolerate 500 mg Cr(VI)/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr(VI)/L in 24 h, achieving the highest removal efficiency at pH 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr(VI)/L at pH 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr(VI) was considered to be bioreduction rather than absorption.
CONCLUSION
The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.
Topics: Biodegradation, Environmental; China; Chromium; Geologic Sediments; RNA, Ribosomal, 16S; Sporosarcina
PubMed: 27003170
DOI: 10.3967/bes2015.014 -
Scientific Reports Apr 2018N-Acyl homoserine lactones (AHLs) act as the key quorum sensing (QS) signal molecules in gram-negative bacteria, which coordinates gene expression and then activates...
N-Acyl homoserine lactones (AHLs) act as the key quorum sensing (QS) signal molecules in gram-negative bacteria, which coordinates gene expression and then activates various processes, including biofilm formation and production of virulence factors in some pathogens. Quorum quenching (QQ), which is the inactivation of the signal molecules by means of enzymatic degradation or modification, inhibits the processes of QS rather than killing the pathogens and is a promising antipathogenic strategy to control the bacterial pathogens. In this study, an AHL lactonase gene (named aiiK) was cloned from Kurthia huakuii LAM0618 and the AHL lactonase AiiK was expressed by Escherichia coli. AiiK exhibits a variable substrate spectrum and efficient degradation of the AHL compounds. The enzyme assays demonstrated that AiiK behaves as an AHL lactonase that can hydrolyze the lactone bond of the AHLs. The total hydrolytic efficiency of AiiK for C-HSL is 3.9 s·mM. AiiK can also maintain 20% activity after 12 h incubation at 37 °C and demonstrate great resistance to α-chymotrypsin, trypsin, and protease K. Furthermore, AiiK significantly inhibits the biofilm formation and attenuates extracellular proteolytic activity and pyocyanin production of Pseudomonas aeruginosa PAO1, which indicates the potential application of AiiK as a biocontrol agent or an anti-pathogenic drug.
Topics: Acyl-Butyrolactones; Bacterial Proteins; Carboxylic Ester Hydrolases; Cloning, Molecular; Gene Expression Regulation, Bacterial; Hydrolysis; Planococcaceae; Pseudomonas aeruginosa; Pyocyanine; Quorum Sensing; Substrate Specificity
PubMed: 29662232
DOI: 10.1038/s41598-018-24507-8