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Author

Ruma Pal

Bio: Ruma Pal is an academic researcher from University of Calcutta. The author has contributed to research in topic(s): Rhizoclonium & Phytoplankton. The author has an hindex of 19, co-authored 75 publication(s) receiving 1256 citation(s).
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Journal ArticleDOI
TL;DR: Pro- and eukaryotic algal genera, i.e. Lyngbya majuscula, Spirulina subsalsa, and Rhizoclonium hieroglyphicum were used for bio-recovery of gold out of aqueous solution indicating quick metabolic independent binding of Au to the algae followed by active accumulation and subsequent reduction.
Abstract: Pro- and eukaryotic algal genera, i.e. Lyngbya majuscula, Spirulina subsalsa (Cyanophyceae) and Rhizoclonium hieroglyphicum (Chlorophyceae), were used for bio-recovery of gold (Au) out of aqueous solution. Au (III) spiked with 198Au was used for the experiment. Batch laboratory experiments indicated quick metabolic independent binding of Au to the algae followed by active accumulation and subsequent reduction. Gold accumulation by different algal genera was found in order of R. hieroglyphicum > L. majuscula > S. subsalsa (3.28, 1.93 and 1.73 mg g-1, respectively). It was observed that the algal biomass and the media used for the experiment turned purple in colour indicating reduction of Au (III) to Au (0) at intra- and extracellular level. This was confirmed by TEM studies of L. majuscula biomass exposed in HAuCl4 solution where <20-nm-sized gold particles were found both inside as well as on the surface of the cell. Up to 90–100% of accumulated gold was recovered from the algal biomass by using nitric acid and acidic thiourea solution.

124 citations


Journal ArticleDOI
TL;DR: Production of gold nanoparticles by algae is more ecofriendly than purely chemical synthesis, however, the choice of algae is important: Chara zeylanica and Pithophora oedogoniana were found to be unable to produce nanoparticles.
Abstract: The cyanobacteria Phormidium valderianum, P. tenue and Microcoleus chthonoplastes and the green algae Rhizoclonium fontinale, Ulva intestinalis, Chara zeylanica and Pithophora oedogoniana were exposed to hydrogen tetrachloroaurate solution and were screened for their suitability for producing nano‐gold. All three cyanobacteria genera and two of the green algae (Rhizoclonium fontinale and Ulva intestinalis) produced gold nanoparticles intracellularly, confirmed by purple colouration of the thallus within 72 h of treatment at 20°C. Extracted nanoparticle solutions were examined by UV‐vis spectroscopy, transmission electron microscopy (TEM) and X‐ray diffractometry (XRD). XRD confirmed the reduction of Au (III) to Au (0). UV‐vis spectroscopy and TEM studies indicated the production of nanoparticles having different shapes and sizes. Phormidium valderianum synthesized mostly spherical nanoparticles, along with hexagonal and triangular nanoparticles, at basic and neutral pHs (pH 9 and pH 7, respectively). Medi...

109 citations


Journal ArticleDOI
01 Jun 2015
TL;DR: In the present communication an attempt has been taken to review the application of different microalgae in rearing of aquaculture animal especially the fishes.
Abstract: Microalgal biotechnology has gained considerable importance in recent decades and its use is extending day by day into several areas like nutraceutical research, renewable energy source, production of essential biomolecules like β-carotene, astaxanthin, PUFA, bio colorant production, wastewater treatment, bioremediation and aquaculture etc. Among all these, microalgae as a source of nutrition have drawn the attention since long back and are widely used in animal nutrition. Fishmeal is the preferred protein ingredient of feed in aquaculture industry, contributing significantly to the variable production cost. However, decreasing fishmeal supply and increasing costs threaten the sustainability and growth of the aquaculture industry. Therefore, complete or partial substitution of fishmeal with alternative proteins is needed to solve the problem. Presently, microalgae are used worldwide as an alternate protein source replacing fishmeal successfully. In feeding trials with fish, many types of microalgae have been found to be used for increasing growth (protein accretion), feed utilization, physiological activity, stress response, starvation tolerance, disease resistance, and carcass quality. In the present communication an attempt has been taken to review the application of different microalgae in rearing of aquaculture animal especially the fishes.

105 citations


Journal ArticleDOI
Abstract: Algal biomass can serve as rich source of bioproducts including lipids for diverse commercial applications. Both biomass production and lipid accumulation are limited by several factors, of which nutrients play a vital role. In the present investigation, the nutritional requirement for the growth by a (an autotrophic) Chlorococcum infusionum was determined using a Plackett–Burman based statistical screening experiment. Five out of the fifteen factors of a reported production medium were found to be significantly affecting the biomass growth. The components NaNO3, K2HPO4, FeSO4.7H2O and KOH had direct proportional correlation with biomass production, while MgSO4 showed inverse proportional relationship in the selected experimental range. Nitrogen was the most influential factor with an effect contribution of 45.77% and a very low p-value of

79 citations


Journal ArticleDOI
Abstract: Intracellular bioconversion of auric ion (Au3+) to gold nanorod (Au0) by the cyanobacterium Nostoc ellipsosporum has been observed for the first time in laboratory condition. The nanorods were produced within the cell after exposing the healthy growing filaments to 15 mg L−1 gold (III) solution (pH 4.5) for 48 h at 20°C. The gold nanoparticles were extracted with sodium citrate solution and were subjected to UV–Visible spectroscopy. The characteristic surface-multiple plasmon bands at 560, 610, and 670 nm were observed. The nature and size of the particles were determined by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential studies. The nanorod size ranged from 137 to 209 nm in length and 33 to 69 nm in diameter. DLS study revealed the average hydrodynamic size as 435 nm and XRD study indicated the reduction of Au3+ to Au0. Methods of extraction and preservation of gold nanorod particles have also been studied.

72 citations


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Journal ArticleDOI
TL;DR: The biosorbents widely used for heavy metal removal were reviewed, mainly focusing on their cellular structure, biosorption performance, their pretreatment, modification, regeneration/reuse, modeling of biosor adaptation (isotherm and kinetic models), the development of novel biosorbent, their evaluation, potential application and future.
Abstract: A vast array of biological materials, especially bacteria, algae, yeasts and fungi have received increasing attention for heavy metal removal and recovery due to their good performance, low cost and large available quantities. The biosorbent, unlike mono functional ion exchange resins, contains variety of functional sites including carboxyl, imidazole, sulphydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl moieties. Biosorbents are cheaper, more effective alternatives for the removal of metallic elements, especially heavy metals from aqueous solution. In this paper, based on the literatures and our research results, the biosorbents widely used for heavy metal removal were reviewed, mainly focusing on their cellular structure, biosorption performance, their pretreatment, modification, regeneration/reuse, modeling of biosorption (isotherm and kinetic models), the development of novel biosorbents, their evaluation, potential application and future. The pretreatment and modification of biosorbents aiming to improve their sorption capacity was introduced and evaluated. Molecular biotechnology is a potent tool to elucidate the mechanisms at molecular level, and to construct engineered organisms with higher biosorption capacity and selectivity for the objective metal ions. The potential application of biosorption and biosorbents was discussed. Although the biosorption application is facing the great challenge, there are two trends for the development of the biosorption process for metal removal. One trend is to use hybrid technology for pollutants removal, especially using living cells. Another trend is to develop the commercial biosorbents using immobilization technology, and to improve the biosorption process including regeneration/reuse, making the biosorbents just like a kind of ion exchange resin, as well as to exploit the market with great endeavor.

2,013 citations


Journal ArticleDOI
TL;DR: Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth, therefore, it does not lead to secondary pollution.
Abstract: Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater.

852 citations


Journal Article
TL;DR: An overview of silver nanoparticle preparation by physical, chemical, and biological synthesis is presented to reflect on the current state and future prospects, especially the potentials and limitations of the above mentioned techniques for industries.
Abstract: Silver nanoparticles (NPs) have been the subjects of researchers because of their unique properties (e.g., size and shape depending optical, antimicrobial, and electrical properties). A variety of preparation techniques have been reported for the synthesis of silver NPs; notable examples include, laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, microwave processing, and biological synthetic methods. This review presents an overview of silver nanoparticle preparation by physical, chemical, and biological synthesis. The aim of this review article is, therefore, to reflect on the current state and future prospects, especially the potentials and limitations of the above mentioned techniques for industries.

809 citations


Journal ArticleDOI
TL;DR: The key applications reviewed here include biomedical applications, especially antimicrobial applications, but also imaging applications, catalytic applications such as reduction of environmental contaminants, and electrochemical applications including sensing.
Abstract: We present a comprehensive review of the applications of biosynthesized metallic nanoparticles (NPs). The biosynthesis of metallic NPs is the subject of a number of recent reviews, which focus on the various ‘‘bottom-up’’ biofabrication methods and characterization of the final products. Numerous applications exploit the advantages of biosynthesis over chemical or physical NP syntheses, including lower capital and operating expenses, reduced environmental impacts, and superior biocompatibility and stability of the NP products. The key applications reviewed here include biomedical applications, especially antimicrobial applications, but also imaging applications, catalytic applications such as reduction of environmental contaminants, and electrochemical applications including sensing. The discussion of each application is augmented with a critical review of the potential for continued development.

292 citations


Journal ArticleDOI
TL;DR: The present review targets the comparative biogenic synthesis and mechanisms of nanoparticles using algae and waste materials (agro waste in the presence of biomolecules) and some of the applications of the biosynthesized nanoparticles in biomedical, catalysis and biosensors fields.
Abstract: The nature acts like a large “bio-laboratory” comprising of plants, algae, fungi, yeast, etc. which are composed of biomolecules. These naturally occurring biomolecules have been identified to play an active role in the formation of nanoparticles with distinct shapes and sizes thereby acting as a driving force for the designing of greener, safe and environmentally benign protocols for the synthesis of nanoparticles. The present review targets the comparative biogenic synthesis and mechanisms of nanoparticles using algae and waste materials (agro waste in the presence of biomolecules). The use of waste materials not only reduces the cost of synthesis but also minimizes the need of using hazardous chemicals and stimulates ‘green synthesis’. It also focuses on the computational aspects of binding of biomolecules to nanoparticles and some of the applications of the biosynthesized nanoparticles in biomedical, catalysis and biosensors fields.

281 citations


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Author's H-index: 19

No. of papers from the Author in previous years
YearPapers
20217
20203
20192
20182
20176
201611