M. Thirunavoukkarasu

Biosynthesis of silver nanoparticle from leaf extract of Desmodium gangeticum (L.) DC. and its biomedical potential

An aqueous leaf extract of Desmodium gangeticum was employed to synthesize silver nano particles. Rapid formation of stable silver nanoparticles were observed on exposure of the aqueous leaf extract with solution of silver nitrate. The silver nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis and transmission electron microscopy (TEM), and Fourier Transform Infra-Red spectroscopy (FTIR) UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM), and Fourier Transform Infra-Red spectroscopy (FTIR). UV-visible spectrum of the aqueous medium peaked at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. SEM analysis revealed the spherical shape of the particles with sizes ranging from 18 to 39 nm and the EDAX spectrum confirmed the presence of silver along with other elements in the plant metabolite. Further, these biologically synthesized nanoparticles were found to be highly toxic against pathogenic bacteria Escherichia coli, thus implying significance of the present study in production of biomedical products.

Screening of Fresh Water Microalgae from Eastern Region of India for Sustainable Biodiesel Production

Study of six different freshwater microalgae, collected from Odisha, eastern region of India, has been carried out to find out their potential for biodiesel production. The growth, total lipid, and fatty acid composition of six microalgal strains were determined. Chlorella sp. IMMTCC-2, which exhibited high lipid content with considerable amount of unsaturated fatty acids, was selected for culture in a self-designed photobioreactor in order to study the scale-up possibilities. The result shows significant increase in lipid accumulation from logarithmic phase to stationary phase in the photobioreactor, i.e., from 12.4 to 28.3%. Analyses of the present results suggest that Chlorella sp. IMMTCC-2 is appropriate for biodiesel production.

ED-XRF spectrometric analysis of comparative elemental composition of in vivo and in vitro roots of Andrographis paniculata (Burm.f.) Wall. ex Nees—a multi-medicinal herb

The multi-elemental composition of in vitro--proliferated root tissues of Andrographis paniculata (Burm.f.) Wall. ex Nees was compared with that of the naturally grown in vivo plants. Trace elements namely Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr and Pb in addition to two macro-elements K and Ca were identified and quantified in root tissues of both sources using the energy dispersive X-ray fluorescence (ED-XRF) technique. ED-XRF analysis was performed using Mo K X-rays generated from a secondary molybdenum target. The elemental content of in vitro roots was found to be at par with that of naturally grown plants of the same species. This opens up a possibility of exploiting in vitro root cultures as a viable, alternative and renewable source of phytochemicals of relevance, besides providing a means for conservation of the valuable natural resources.

ED-XRF spectrometry-based comparative inorganic profile of leaf-derived in vitro calli and in vivo leaf samples of Phyllanthus amarus Schum. & Thonn.--a hepatoprotective herb.

The Energy Dispersive X-ray Fluorescence (ED-XRF) set-up incorporating a molybdenum secondary exciter was used for quantitative determination of major and minor elements in leaves of in vivo grown medicinal herb Phyllanthus amarus vis-á-vis its leaf-derived in vitro callus culture. The elements such as K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr and Pb were identified, quantified and compared between both the sources. Experimental results revealed that, compared to the naturally grown herb, in vitro leaf-derived callus cultures were more efficient in accumulating inorganic elements, especially trace elements, which are essential for growth and development and more importantly for prevention and cure of diseases. This investigation on a medicinal plant species is the first of its kind to have used the ED-XRF technique to demonstrate a comparative account of the elemental profile of in vitro callus cultures with their in vivo donor in order to explore the possibility of exploiting the former as a viable alternative and a renewable source of phytochemicals.

Solvent mediated tuning of selectivity in a rhodamine based probe and bioimaging for Pb(II) detection in plant tissues

A substituted rhodamine based probe, which exhibits dual mode signalling responses of altered selectivity as a function of variation in solvent medium, demonstrates its utility as an imaging agent for the determination of Pb(II) accumulation in the roots of Aerva lanata plant species.

Cultivation of freshwater microalga Scenedesmus sp. using a low-cost inorganic fertilizer for enhanced biomass and lipid yield

The potential of an inorganic fertilizer as an alternative nutrient source for the cultivation of Scenedesmus sp. IMMTCC-6 was investigated. With a preliminary study at a shake-flask scale, the microalgae cultivation was scaled up in a photobioreactor containing an inorganic fertilizer medium. Microalgae cultured in a shake flask containing 0.1 g L(-1) of urea and 1.0 g L(-1) of NPK (Nitrogen: Phosphorus: Potassium) fertilizers showed a promising result in biomass productivity. During the scale-up study in a photobioreactor the specific growth rate (μ d(-1)), biomass yield (g L(-1)), and total biomass productivity (mg L(-1) d(-1)), was found to be 0.265, 1.19 and 66.1, respectively. The lipid yield (%) as per dry cell weight (DCW) and lipid productivity (mg L(-1) d(-1)) was found to be a maximum of 28.55 and 18.87, respectively, in a stationary phase of the microalgae growth. The fatty acids methyl ester profile was proven to be desirable for biodiesel production.

Micropropagation of Enterolobium cyclocarpum (Jacq.) Griseb

Abstract Shoot multiplication was achieved from cotyledon and hypocotyl segments of in vitro germinated seedlings of Enterolobium cyxclocarpum on Murashige and Skoogs medium supplemented with BA (0.5-2.0 mg/L) and IAA (0.1-0.3 mg/L). Among the different concentrations and combination tested, BA (1.0 mg/L) in combination with IAA (0.2 mg/L) stimulated the best response in terms of shoot bud formation from cotyledon expiants in which a maximum of 60% culture responded, with a maximum of 2.7 ± 0.3 shoot buds per expiant with a mean shoot length of 2.0 ±0.2 cm. A maximum of 80% of the hypocotyl expiants exhibited such organogenic response when cultured on MS medium supplemented with 1.5 mg/L BA and 0.2 mg/L IAA with a mean shoot bud number of 4.1 ± 0.3 per expiant and a mean shoot length of 2.7 ±0.1 cm. Elongated shoots could be rooted on the half-strength MS basal medium supplemented with either IAA or IBA. Cotyledonary node expiants showed poor response.

Clonal Propagation and Antimicrobial Activity of Vitex negundo L. An Endemic Medicinal Plant

Abstract We outline a highly efficient and reproducible protocol for micropropagation from nodal explants of Vitex negundo and further comparative antimicrobial screening of the leaf extracts of in vitro and field raised plants of Vitex negundo. Murashige and Skoog (MS) medium supplemented with 0.25 mg/L N-benzyl amino purine and 0.25 mg/L α-napthelene acetic acid was found to be most effective in inducing bud break and in initiating maximum (8.26±0.88) multiple shoot proliferation per nodal explant after 30 days of culture. Half strength MS medium supplemented with 0.5 mg/L Indole-3-butyric acid was found to be best for rooting. Methanol leaf extracts of in vitro and in vivo plants were screened for potential antimicrobial activity against medically important bacterial strains by minimum inhibitory concentration method. Both in vitro and in vivo leaf extracts showed similar antimicrobial activity, with Gram positive strains exhibiting greater sensitivity than Gram negative strains. These findings suggest that in vitro propagation techniques could serve as an extremely feasible and profitable source for commercial manufacture of active constituents with consistent antibacterial properties.

Essential Oils from Leaves of Micropropagated Ruta graveolens

Abstract The essential oils of Ruta graveolens were analysed by GC and GC-MS. Comparisons were made between field-grown plants and micropropagated plants of the same clone. Oil content of in vitro-grown plants was marginally more (0.84 %) in comparison to that of conventional grown source plant (0.80 %). The most common components usually found in Ruta oils were present in the oil samples analysed and 17 constituents were identified in leaves of in vitro grown plants (representing 97.2 %) whereas 18 compounds (representing 90.27 %) were identified in leaves of field raised plants. The essential oils from fieldgrownplants of Ruta graveolens, when compared with those from micropropagated plants of the same clone, showed that the same major components were present without significant compositional variations. The most abundant constituents of the oils were 2-undecanone and 2-nonanone. Further, efforts were made to increase the oil yield by enhancing the leaf biomass by manipulation of physiological conditions. Increase in the leaf biomass by inducing shoot production in Murashige and Skoog media fortified with BA 2 mg/1 + IAA O.5mg/1 + adenine sulphate 50 mg/1 resulted in significant increase in the oil yield.