Ruma Pal

Bio: Ruma Pal is an academic researcher from University of Calcutta. The author has contributed to research in topics: Rhizoclonium & Phytoplankton. The author has an hindex of 19, co-authored 75 publications receiving 1256 citations.

Biochemical composition and lipid characterization of marine green alga Ulva rigida- a nutritional approach

Abstract: Biochemical composition of the green alga Ulva rigida (Ulvophyceae) was investigated by determination of moisture, protein, carbohydrate, total lipid, phenol and chlorophyll content.The moisture content of the alga was 76% whereas total protein was 6.64%, and carbohydrate content was 22%. The total lipid and phenol content were 12% and 23% whereas chlorophyll a, b and total chlorophyll were determined as 13%. 7.5% and 21% respectively. Carotenoid was present in considerable quantities (4.5%). The total free amino acid was found to be 8.9%. Fatty acid composition of total lipid was determined by gas chromatography. The major fatty acids in total lipid were 14:0, 16:0, 18:0, 18:1, 18:2 and 18:3. It was found that major of the biochemical parameters of this alga were higher except the protein content.

Diatom: A potential bio-accumulator of gold

Abstract: The bioaccumulation of gold in trace concentration by Nitzschia obtusa and Navicula minima, two members of bacillariophyceae, has been studied. It has been observed that Nitzschia obtusa showed better accumulation of gold in acidic pH in comparison to neutral and basic pH. Maximum accumulation was observed with 1 mg . kg-1 or less gold concentration. However, the accumulation by the living cells was reduced when the matrix concentration was higher. Navicula minima, on the other hand, found to be a better accumulator of gold in wide ranges of pH and substrate concentration of the media. It was also inferred that the gold accumulation by diatom was mainly due to adsorption by biosilica (siliceous frustules of dead diatom cells). Accumulated gold was recovered with conc. HNO3.

Green Synthesis of Gold Nanoparticles Using Cyanobacteria and their Characterization

Abstract: Two cyanobacteria Lyngbya majuscula and Spirulina subsalsa were used as bioreagent for the green synthesis of gold nanoparticles. Within 72 h of incubation at 15 mg L-1 Au3+ solution, the cyanobacterial biomass turned purple indicating intracellular reduction of Au3+ to Au0 and subsequent formation of gold nanoparticles. Gold nanoparticles were extracted from the gold-loaded biomass using 7.5 mM sodium citrate solution and characterization was done by UVvisible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). While Spirulina showed synthesis of spherical nanoparticles of 5 nm -30 nm diameter along with very few nanorods, Lyngbya showed presence of spherical and hexagonal nanoparticles of 2 nm -25 nm diameters. XRD study confirmed the reduction of Au3+ to Au0. FTIR analysis indicated the presence of protein shells around the gold nanoparticles.

Microalgae in Biotechnological Application: A Commercial Approach

Abstract: Microalgae are used as food, feed, and fodder and also used to produce a wide range of metabolites such as, proteins, carbohydrates, lipids, carotenoids, vitamins, fatty acids, sterols, etc. They are able to enhance the nutritional content of conventional food and feed preparations and hence positively affect humans and animal health including aquaculture animals. They also provide a key tool for phycoremediation of toxic metals and nanometal production. The use of microalgae in nanotechnology is a promising field of research with a green approach. The use of genetically modified algae for better production of different biotechnological compounds of interests is popular nowadays. Microalgal biomass production for sustainable biofuel production together with other high-value compounds in a cost-effective way is the major challenge of algal biotechnologists. Microalgal biotechnology is similar to conventional agriculture but has received quite a lot of attention over the last decades, because they can reach substantially higher productivities than traditional crops and can use the wastelands and the large marine ecosystem. As history has shown, research studies on microalgae have been numerous and varied, but they have not always resulted in commercial applications. The aim of this review is to summarize the commercial applications of microalgae.

Synthesis of silver nanoparticles: chemical, physical and biological methods.

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.

Synthesis and biological characterization of silver nanoparticles derived from the cyanobacterium Oscillatoria limnetica.

Abstract: Using aqueous cyanobacterial extracts in the synthesis of silver nanoparticle is looked as green, ecofriendly, low priced biotechnology that gives advancement over both chemical and physical methods. In the current study, an aqueous extract of Oscillatoria limnetica fresh biomass was used for the green synthesis of Ag-NPs, since O. limnetica extract plays a dual part in both reducing and stabilizing Oscillatoria-silver nanoparticles (O-AgNPs). The UV-Visible absorption spectrum, Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were achieved for confirming and characterizing the biosynthesized O-AgNPs. TEM images detected the quasi-spherical Ag-NPs shape with diverse size ranged within 3.30–17.97 nm. FT-IR analysis demonstrated the presence of free amino groups in addition to sulfur containing amino acid derivatives acting as stabilizing agents as well as the presence of either sulfur or phosphorus functional groups which possibly attaches silver. In this study, synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast (MCF-7) cell line giving IC50 (6.147 µg/ml) and human colon cancer (HCT-116) cell line giving IC50 (5.369 µg/ml). Hemolytic activity of Ag-NPs was investigated and confirmed as being non- toxic to human RBCs in low concentrations.