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Protein Mediated Silica Particles with pH Controlled Porosity and Morphology

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Advances in Microbiology 2016年第14期6卷 986-998页

作者： Shilpi Show brajadulal chattopadhyay Department of Physics Jadavpur University Kolkata India

Background: The silica leaching activity of some of the mystifying non-pathogenic BKH1 bacteria present in the cluster of hot springs (temperatures range 35°C - 80°C) at Bakreshwar (West Bengal, India, 23°52'48"N;87°22'40"N) has provided some significant advancements in the field of nanotechnology. The present investigation was designed to synthesis the silica particles using bioremediase protein at different pH conditions. Methods: A secretary bacterial protein bioremediase (UniProt Knowledgebase Accession Number P86277) isolated from a thermophilic non-pathogenic bacterium BKH1 (GenBank Accession No. FJ177512) has been used to synthesis the silica particles at different pH conditions (pH at 3.0, 5.0, 8.0, 10.0, and 12.0 respectively). The silica particles were synthesized by the action of bioremediase protein on Tetra-ethyl-orthosilicate (TEOS) under ambient condition. Morphological and compositional studies of the biosynthesized silica particles were characterized by Field emission scanning electron microscope (FE-SEM) equipped with Energy dispersive X-ray analyser (EDX). Results: The Fourier transformed infra-red (FTIR) spectroscopic analysis confirmed the nature as well as occurrence of several functional groups surrounded on the silica particles. The amorphous nature of the prepared silica particles was confirmed by X-ray diffractometer (XRD) study. The Zeta potential (ζ) study revealed the stability of silica particles in neutral pH environment. The Brunauer-Emmett-Teller (BET) surface area measurement confirmed the porosity variation in all biosynthesized silica particles prepared at different pH conditions. Raman spectra analytically depend on their respective specific surface (BET) area. Thermogravimetry tool was used to monitor the effects of the thermal treatment on the surface properties of all the samples. Conclusions: The method for the synthesis of silica particles at different pH condition using the protein bioremediase has a special implication as

关键词： Bioremediase Protein Tetraethyl Orthosilicate Green Chemistry Silica Particles Porosity

Root Extracts (<i>Gymnadenia orchidis</i>Lindl) Facilitated Rapid Synthesis of Fluorescent Silver Nanoparticles (Ag-NPs) for Various Biological Applications

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Journal of Biomaterials and Nanobiotechnology 2017年第1期8卷 109-124页

作者： Shilpi Show Chetana Ghosal brajadulal chattopadhyay Department of Physics Jadavpur University Kolkata India

One pot rapid and green bio-synthesis of stable fluorescent silver nanoparticles (Ag-NPs) from silver nitrate solution using root extract of Gymnadenia orchidis Lindlat at ambient temperature is demonstrated productively. Surface Plasmon resonance of the synthesized Ag-NPs was shown to occur at 439 nm and two sharp fluorescence peaks at 610 and 780 nm were observed. FTIR study publicized the presence of chemically functional groups in the root extract surrounding the Ag-NPs, acting as stabilizers. XRD and FESEM analysis revealed that Ag-NPs were face centred cubic structure being spherical in shape with an average particle size of 28 ± 2 nm (n = 100). The stability of Ag-NPs in neutral pH environment was confirmed by Zeta Potential (ζ) behaviour. The Ag-NPs showed superior antioxidant activity. The notable photo-catalytic activity of biosynthesized Ag-NPs attributed to the existence of some proteins, responsible for degradation of methylene blue dye. Furthermore, Ag-NPs were found to exhibit a significant antibacterial effect against gram positive Staphylococcus aureus (S. aureus) bacteria.

关键词： Green Synthesis Gymnadenia orchidis Lindl Silver Nanoparticles DPPH Photo-Catalytic Antibacterial

Removal of Lead Contamination through the Formation of Lead-Nanoplates by a Hot Spring Microbial Protein

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Advances in Microbiology 2021年第11期11卷 681-693页

作者： Chetana Ghosal Nurul Alam Abiral Tamang brajadulal chattopadhyay Department of Physics Jadavpur University Kolkata India

Lead contamination still remains as serious threat to public health and environment because of its non-biodegradability and toxicity. A clean technique has been developed for removal of lead contamination through the formation of lead-oxide nanoplates using a bacterial protein (Molecular weight ~30 kDa) as biological template. The isolated hot-spring bacterial (the bacterium was named as MDH1) protein when adding to the solution of lead compound (e.g., lead nitrate), nanoplates of lead-oxide are formed as viewed by electron microscope. The as prepared lead-oxide-nanoplates are characterized by Inductively Coupled Plasma analysis, Energy Dispersive X-ray Spectroscopy and X-ray diffraction analyses. The lead-oxide-nanoplates and the filtered supernatant of the reactive solution both were separately used to observe the inhibition of growth of E. coli bacteria on culture plate. Lead-oxide-nanoplates produced clear zone of inhibition on the bacterial growth plate, whereas the filtered supernatant exhibited no such zone on the growth of E. coli bacteria revealing the fact that lead contamination was removed from the filtered supernatant. The prepared lead oxide nanoplates also possess dye degradation activity which is the added advantage of the process. The MDH1 bacterial protein acts as biological template which successfully removes lead contamination from lead-solution. The process is a clean and cost-effective one which can be used not only for removal of lead contamination but also for removal of different dyes from environment due to having dye-degradation attribute of the lead-oxide nanoplates.

关键词： Bacteria Hot Spring Protein Dye Degradation Lead-Oxide Nanoplates

Phylogenetic Characterization of BKH3 Bacterium Isolated from a Hot Spring Consortium of Bakreshwar (India) and Its Application

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Advances in Microbiology 2016年第6期6卷 453-461页

作者： Biswadeep Chaudhuri Nurul Alam Manas Sarkar Trinath Chowdhury brajadulal chattopadhyay Department of Physics Jadavpur University Kolkata India

Background: The silica leaching attribute of some of the mystifying bacteria present in the cluster of hot springs (temperatures range 35°C - 80°C) at Bakreshwar (West Bengal, India, 23°52'48"N;87°22'40") has provided some significant advancements in construction technology when incorporated to the concrete/mortar specimens. The present investigation was designed to isolate other novel bacterial strains from 65°C hot spring that could have similar or better performance in construction technology. Methods: Soil sample collected from the 65°C hot spring was inoculated to the culture vials (incubated at 65°C) containing a specific synthetic growth medium (pH 8.0) to grow the bacterial population anaerobically by degassing the medium with CO2 gas. Subsequent serial dilution techniques were employed to isolate pure culture of a specific bacterial strain. 16S rRNA gene sequence and phylogenetic analysis was carried out to identify the novelty of the isolated bacterial strain. The isolated bacteria were incorporated to the cement sand mixture at various cell concentrations to evaluate the efficacy of the strain in construction technology. Results: The work revealed the presence of a novel bacterial strain (BKH3;GenBank Accession No.: KP 890928) within the same hot spring consortium whose 16S rRNA gene sequence data showed 96% identity with Citrobacter freundii bacterial species. The newly isolated bacteria when incorporated at different cell concentration to the cement/cement-sand mixture were found to possess the similar compressive strength increment property, the cracks repairing ability and the water ingression resistivity. It also reduced the permeability of sulphate ions to the cementitious matrix reflecting the increment of durability of the incorporated material. Conclusions: The enhancement of compressive strength and durability of the as prepared bio-concrete material by using the isolated bacterial strain (BKH3) was due to

关键词： Bioconcrete Compressive Strength Hot Spring 16S rRNA Phylogenetic Analysis

Characterization of a Novel MDH1 Bacterium from a Virgin Hot Spring Applicable for Gold Nanoparticle (GNPs) Synthesis

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Advances in Microbiology 2016年第9期6卷 724-732页

作者： Nurul Alam Manas Sarkar Trinath Chowdhury Dipak Ghosh brajadulal chattopadhyay Department of Physics Jadavpur University Kolkata India

Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot spring of Metaldanga, Birbhum, West Bengal, India. Methods: A pure bacterial strain (MDH1) was identified by growing the enrichment culture isolated from Metaldanga hot spring through serial dilution process in a semi-synthetic medium at pH 8.0 and 42°C temperature. The novelty of the strain was characterized by 16S-rRNA gene sequence analysis. The bacterium acted as template to synthesize spherical gold nanoparticles (GNPs). GNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infra-red spectroscopy (FTIR). Results: The phylogenetic analysis suggested that MDH1 strain (GenBank accession number: KT600031) was affiliated to the family “Pseudomonadaceae” with 99% homologous to Pseudomonas putida H8234. The coccoid shaped bacterium was gram-negative and facultative-anaerobic which acted as a template to synthesize spherical GNPs with an average size of 12 ± 3 nm when examined under transmission electron microscopy (TEM). FT-IR studies revealed the presence of bioactive functional groups which acted as capping and stabilizing agents of the GNPs. XRD pattern confirmed the amorphous nature of GNPs. The Zeta potential (ζ) concluded the adequate stability of GNPs in an aqueous environment. Conclusions: The present investigation explores the microbial diversity of a virgin hot spring of Metaldanga for its beneficial applications in industry, particularly in the synthesis of the gold nanoparticles.

关键词： Hot Spring Bacteria Phylogenetic Characterization Green Synthesis Gold Nanoparticles

Use of Bacterial Protein Powder in Commercial Fly Ash Pozzolana Cements for High Performance Construction Materials

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Open Journal of Civil Engineering 2012年第4期2卷 218-228页

作者： Sudipta Majumdar Manas Sarkar Trinath Chowdhury brajadulal chattopadhyay Saroj Mandal Department of Civil Engineering Jadavpur University Kolkata India Department of Physics Jadavpur University Kolkata India

Concrete, widely used construction material suffers from cracks and low tensile strength that cut down the load capacity resulting in shortening of self-life. Biologically modified construction materials become more popular for higher strength and long-term sustainability. This investigation deals with the compressive and flexural strengths increment of a novel bacterial protein (bioremediase) incorporated pozzolana cement based mortar specimens. This protein also increases durability and crack repairing attributes that is more effective in pozzolana cement. Higher constituent percentage of silicate in pozzolana cement leads to higher silica leaching activity within the matrix manifesting of higher strength and durability of the samples. Eco-friendliness and wide range temperature stability lead added advantage to the protein for potential additive in high performance concrete technology. This means in practice that a substantial part of the cement of the mortar/concrete mixtures can be left out while still obtaining needed final strength. This would substantially improve the ecological footprint (sustainability) of mortar/concrete, as it is particularly cement that causes (during its production) massive CO2 emission what negatively affects the global climate (significantly contributes to global warming).

关键词： Compressive Strength Durability Microbial Protein Pozzolana Cement