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.

Evaluation of algae based feed in Goldfish ( Carassius auratus ) nutrition

Abstract: A short term laboratory feeding trial was conducted to evaluate the importance of algae based value added feed for the popular ornamental fish Carassius auratus (Gold fish). The feed was tested against Daphnia — the conventional feed used for Goldfish. Fresh algal biomass of Nostoc ellipsosporum and Navicula minima were mixed with daphnia to formulate the value added feed and proximate composition of feeds were analyzed. The experimental feed showed significantly higher protein (71.24% ±0.3), lipid (33.47%±0.2), and carotenoid (6.41%±0.13) (Pd″0.05), and increased level of amino acids (4.2%±0.1) and carbohydrate (14.72%±0.2) content than the control feed. Similarly the fishes fed with experimental feed showed 2 fold increase in protein, glycogen and carotenoid level as compared to the control fishes. Morphometric study also showed significant Body weight Gain (3.52%±1.2) and Specific growth rate (0.87±0.41) together with high Protein Productive value (0.051±0.14), Protein effficiency ratio (0.074±0.05) and low Feed conversion ratio (0.024±0.03) in experimental fishes which signifies better utilization of feed by the fishes. The VAF (Value added feed) fed fishes showed positive results in both morphometry and carcass proximate composition. Differences in body weight gain and Feed conversion ratio together with increased protein, glycogen and carotenoid levels were significant than the control fishes. The colouration of the gold fishes induced by algal carotenoids was more bright and vibrant indicating high market value.

Synthesis and Characterization of Nanosilver-A blue green approach

Abstract: In our thorough investigation of suitability of cyanobacterial strains, commonly known as blue green algae, for cheap ecofriendly nanometal formation, Leptolyngbya valderianum was found to be an effective bioreagent for nanosilver production. The nanosilver synthesis at intracellular level was indicated by the brown biomass of Leptolyngbya after 72 hrs of dark exposure in 9 mM AgNO3 solution. Intracellular silver particles were extracted from the silver loaded biomass and nanosilver production was determined by UV-vis spectroscopy showing absorption peak at ~411 nm. Extracted nanoparticles were further characterized by dynamic light scattering (DLS), zeta potential and X-ray diffraction (XRD) studies. Transmission electron microscopy (TEM) revealed the spherical shape of AgNPs with 2 to 20 nm in diameter. The XRD indicated the 2θ values at 38.20, 44.50, 65.60 and 78.60 which confirmed again the reduction of Ag (I) to Ag (0). Antibiotic property of the AgNP was tested by Agar well diffusion method. Introduction Silver nanoparticles commonly used for nanomedicine production , are reported to be nontoxic to human but most effective against bacteria, viruses, and other eukaryotic microorganisms at very low concentration (Jeong et al. 2005). They are also effective against tumors with anti-proliferative activity (Sriram et al. 2010). The antimicrobial property allows them to be suitably employed in numerous products such as textiles, food storage containers, home appliances and especially in medical devices (Marambio-Jones et al. 2010). Use of AgNP is in medicine industry as tropical ointments to prevent infection against burn and open wounds is quite effective (Ip et al. 2006). Silver nanoparticles (AgNPs) play important role as pesticide filter also (Pradeep and Anshup 2009). Silver nanoparticles are synthesized by different physical and chemical methods like sol-gel technique, solvo-thermal synthesis, chemical reduction, laser ablation, inert gas condensation etc (Huy et al. 2013). The time consuming physical methods are often difficult to achieve and in chemical methods different toxic reagents are used as capping agent like, cetyl trimethyl ammonium bromide (CTAB) leading to undesirable functional aberrations in target cells. Both physical and chemical procedures are very expensive also. Therefore biosynthesis of AgNPs are becoming popular day by day using microorganisms like bacteria (Klaus et al. 1999, Sweeney et al. 2004, Nair and Pradeep 2002); fungi (Ahmad et al. 2003, Ingle et al. 2009, Mukherjee et al. 2001, Gade et al. 2008, Sanghi et al. 2009) and algae (Govindaraju et al. 2009, Mohseniazar et al. 2011). Only sporadic reports are available regarding filamentous cyanobacteria based AgNP production like, Plectonema boryanum(Lengke et al. 2007), Oscillatoria willei (Ali et al. 2011) and Spirulina platensis (Govindraju et al. 2008). In search for a very suitable bio-reagent for AgNP production, we recorded Leptolyngbya valderianum as more effective strain, as it is widespread in distribution than the studied taxa. They flourish from freshwater to marine region, moreover very cheap production of biomass is possible within very short time reducing the production cost of the nano-metal. Size determination was done in the present investigation employing TEM study and complete characterizations of AgNP were made by XRD, DLS, and Zeta potential studies. Rate of AgNP production per gm biomass was determined and pure nanometal was extracted from the biomass. Antibiotic property was determined by agar well diffusion methods. All these studies would analyze the structure and stability of AgNP in pure form and can be used for further exploitation. Materials and methods The experimental strain, L. valderianum was collected from eastern part of India (Suderbans, West Bengal) and pure strain was obtained from Phycology Laboratory, CU. A small portion of healthy growing biomass (10 mg FW) was exposed to 100 ml of 9 mM Ag (I) solution (pH 3.86), (AgNO3, MW 169.86, Merck, India) and was kept in dark condition at room temperature. After 72 h yellowish brown biomass was removed from the silver nitrate solution and washed with double distilled water. To extract the particles, algal biomass was sonicated for 30 min at 60% amplitude with 7.5 mM sodium citrate solution by a Hielscher UP100H ultrasonic processor (Teltow, Germany) and was centrifuged at 3000 rpm for 5 min in a C-24 BL Remi cooling centrifuge (Maharashtra, India). The supernatant was collected for further analysis. A UV-vis spectrum of the extract was recorded in the wavelength range of 200nm-1100nm with a Thermo Evolution 300 UV-visible spectrophotometer (Waltham, USA). DLS measurement was done with 1 mL of suspension using Nano ZS (Malvern) to study the hydrodynamic size of the particles distributed in citrate solution. Zeta potential of the suspension was determined using the same instrument to determine the stability of the nanoparticles. Silver loaded brown colored biomass was air-dried, made it into powder using mortar and pestle and used for powder XRD analysis. The XRD spectra were recorded from 5° to 100° 2θ angles with a Panalytical PW 3040/60, DY 2501 X-ray diffractometer (Netherland) using Cu Kα radiation operated at 40 kV and 30 mA to confirm the presence of Ag (0). A drop of nanoparticle extract was dried on a carbon coated copper grid and the morphology and size analysis of biosynthesized AgNPs was carried out by JEOL JEM 2100 HR-TEM. The extracted golden brown suspension was lyophilized and nano silver production rate was determined in relation to biomass weight (mg/gm biomass). Antibacterial activity of the synthesized silver nanoparticles was determined using the agar well diffusion method against gram negative bacteria Pseudomonas aeruginosa (MTCC 424). The bacterial strain was obtained from Microbial type culture collection and gene bank (MTCC, Chandigarh, India). The inoculums suspensions were spread uniformly in different nutrient agar plates. Cavities were made in each plate using a well-cutter and it was filled with silver nanoparticle solution (100 ml) with different concentions, 1 mg/ml, 0.5 mg/ml, and 0.1 mg/ml and then incubated at 37 °C. Sodium citrate was used as negative control because AGNPs were suspended in citrate solution. The diameter of clear zone was measured.

Variations in seasonal phytoplankton assemblages as a response to environmental changes in the surface waters of a hypo saline coastal station along the Bhagirathi-Hooghly estuary.

Abstract: Due to the close proximity of the Bay of Bengal and the freshwater inflow of Bhagirathi–Hooghly, Diamond Harbour appeared as an important coastal station of the Bhagirathi–Hooghly estuary. The spatial and temporal composition and abundance of microphytoplankton species was examined in relation to physical and chemical surface water variables (i.e., salinity, nutrient, and temperature).The primary objective of the study was to observe the variations in phytoplankton species assemblages as a response to environmental variables. Hierarchical cluster analysis and non-metric multidimensional scaling were used to find out distinct seasonal groups based on the composition of phytoplankton. The results indicate that several key environmental factors like temperature, DIN content, and molar ratio of nutrients like DIN–DIP and DIN–DSi influenced seasonal phytoplankton assemblages within the estuary. The distribution of phytoplankton population showed two main groups where the blue-green and green algal populations favored the warmer conditions of summer and monsoon months, whereas the diatom population primarily flourished in the cooler months of autumn and winter.

Composite algal supplementation in nutrition of Oreochromis mossambicus

Abstract: Composite algal mix has been used as feed supplement in nutrition of Oreochromis mossambicus and its effect on growth performance, feed efficiency, nutrient utilisation and body composition was investigated in a 12 week feeding trial. Three isonitrogenous diets containing 0 % (conventional feed, CF), 35% (value added feed, VAF) and 100% (algal feed, AF) algal supplementation were used in combination with other conventional fish feed ingredients. The algal genera used were Phormidium valderianum, Spirulina subsalsa, Navicula minima, Chlorococcum infusionum and Rhizoclonium riparium in a ratio of 35:35:12:12:6 for experimental feed formulation. Fish fed with VAF showed an increased growth performance (P < 0.05), feed efficiency and nutrient utilisation compared to 0 % and 100% supplemented diets. Carcass lipid levels decreased at 35% supplementation level. The results suggested that, 35 % supplementation of conventional feed with composite algal mix can be used in mossambique tilapia diet.

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.