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Cement, the primary construction material, releases a substantial quantity of CO2 (about 5–7% of total CO2 emission) in the atmosphere during its production, thereby causing global warming. Fly ash is a coal combustion by-product that leads to many environmental problems like ground water contamination, spills, heavy metal contamination, etc. To overcome the serious ecological problems and health hazards of cement industries and thermal power plants, development of clean binding materials for construction purposes has become an interesting and new aspect of research to the scientific communities. This study has been designed to develop and characterize 100% fly ash-based geopolymer by incorporating improved Bacillus subtilis cells which may be used for cement alternative in future. The designed geopolymer showed significantly increased compressive, flexural and tensile strengths, reduced water absorption capacity and increased sulphate and chloride resistance attributes. It also possesses enhanced durability with high-temperature tolerance (400 °C) compared to cementitious material. Microstructure analysis showed more compactness, reduced porosity and development of new phases inside the geopolymer matrix. The newly developed 100% fly ash-based geopolymer is an eco-efficient material which will reduce the pollution caused by fly ash and be used for sustainable construction purposes in the near future. [ABSTRACT FROM AUTHOR]

Nicotine aggravates many chronic inflammatory disorders in females under the protein-malnourished conditions because women are more susceptible to nicotine-induced diseases due to their low innate immunity. Although curcumin have been found to obliterate the nicotine-induced disorders through its anti-nicotinic activity under the protein-malnourished condition, the exact mechanism of protective action of curcumin is still unclear. Female Wister rats maintained under the normal and protein-restricted diets in two separate groups were injected with the effective dose of nicotine-tartrate (2.5 mg/kg body weight/day, subcutaneously) and supplemented with the effective dose of curcumin (80 mg/kg body weight/day, orally) for 21 days. The morphology of red blood cells (RBCs), molecular docking, lipid profile and activities of antioxidant enzymes in tissues, cytokines profiling (T helper cell type 1; and T helper cell type 2), mRNA and protein expression of cytokines, transcription factors (activator protein 1), regulatory molecule (P), growth factors (Granulocyte-macrophage colony-stimulating factor; Transforming growth factor beta) were determined to establish the mechanism of actions of curcumin against the nicotine-mediated stress in the protein-malnourished rats. This study revealed that curcumin bound to the Histidine 87 residues of haemoglobin with a greater binding affinity and significantly protected the RBCs against nicotine-induced damage. Furthermore, the nicotine-mediated disruption of Th1/Th2 balance through upregulation and downregulation of different factors was effectively restored by curcumin under the protein-malnourished conditions. The study demonstrated that curcumin was a potent protective compound against the nicotine-induced stress and offered a probable biochemical and immunomodulatory mechanism of protective action of curcumin. [ABSTRACT FROM AUTHOR]

A unique protein, bioremediase (UniProt Knowledgebase Accession No.: P86277), isolated from a hot spring bacterium BKH1 (GenBank Accession No.: FJ177512), has shown to exhibit silica leaching activity when incorporated to prepare bio-concrete material. Matrix-assisted laser desorption ionization mass spectrometry analysis suggests that bioremediase is 78 % homologous to bovine carbonic anhydrase II though it does not exhibit carbonic anhydrase-like activity. Bioinformatics study is performed for understanding the various physical and chemical parameters of the protein which predicts the involvement of zinc encircled by three histidine residues (His94, His96 and His119) at the active site of the protein. Isothermal titration calorimetric-based thermodynamic study on diethyl pyrocarbonate-modified protein recognizes the presence of Zn in the enzyme moiety. Exothermic to endothermic transition as observed during titration of the protein with Zn discloses that there are at least two binding sites for zinc within the protein moiety. Addition of Zn regains the activity of EDTA chelated bioremediase confirming the presence of extra binding site of Zn in the protein moiety. Revival of folding pattern of completely unfolded urea-treated protein by Zn explains the participatory role of zinc in structural stability of the protein. Restoration of the λ in intrinsic fluorescence emission study of the urea-treated protein by Zn similarly confirms the involvement of Zn in the refolding of the protein. The utility of bioremediase for silica nanoparticles preparation is observed by field emission scanning electron microscopy. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The self-bioremediation in cementitious composite material is one of the most interesting avenues relating to damage management and self-life of constructions, which needs to be cogitated. The self-bioremediation of a microbial protein-impregnated cementitious material has been explored in this work. The bioremediase protein was isolated from a hot spring bacterium (BKH1) and incorporated at three different concentrations into commercial Pozzolana cements that are widely used for mortar sample preparation. Artificial cracks were generated within the mortar samples by applying partial breaking load (50 %) and the samples were cured under water for different days. Image analysis by Crackscope and microstructure analysis by field emission scanning electron microscope ascertained the formation of irregular crystalline healing material within the cracks of the test samples. X-ray diffractometer and energy dispersive spectra analyses confirmed that the irregular crystalline structures were due to the deposition of new silicate phase (Gehlenite) within the cracks. Increase of ultrasonic pulse velocity and compressive strength, augmentation of sulphate resistance, decrease of chloride permeability and water absorption capacity revealed that there were overall improvement of mechanical properties and durability of the protein-incorporated mortar samples compared to the control (without protein incorporation) mortar samples. This cost effective and eco-friendly self-bioremediation phenomenon observed in mortar is evolved due to the biosilicification activity of bioremediase protein when amended in mortar samples. The exceptional potential of the microbial bioremediase protein for self-bioremediation attribute may add a new dimension in self-healing construction technology in near future. [ABSTRACT FROM AUTHOR]