Biosorptive removal of arsenic from drinking water

A biomass derived from the plant Momordica charantia has been found to be very efficient in arsenic(III) adsorption. An attempt was made to use this biomass for arsenic(III) removal under different conditions. The parameters optimized were contact time (5-150 min), pH (2-11), concentration of adsorbent (1-50 g/l), concentration of adsorbate (0.1-100mg/l), etc. It was observed that the pH had a strong effect on biosorption capacity. The optimum pH obtained for arsenic adsorption was 9. The influence of common ions such as Ca(2+), Mg(2+), Cd(2+), Se(4+), Cl(-), SO(4)(2-), and HCO(3)(-), at concentrations varying from 5 to 1000 mg/l was investigated. To establish the most appropriate correlation for the equilibrium curves, isotherm studies were performed for As(III) ion using Freundlich and Langmuir adsorption isotherms. The pattern of adsorption fitted well with both models. The biomass of M. charantia was found to be effective for the removal of As(III) with 88% sorption efficiency at a concentration of 0.5mg/l of As(III) solution, and thus uptake capacity is 0.88 mg As(III)/gm of biomass. It appears that this biomass should be used as a palliative food item. Further it also appears that the dietary habits may play a role in the toxic effects of ingested arsenic.     

Evaluation of the toxicity of different phytoextracts of Ocimum basilicum against Anopheles stephensi and Culex quinquefasciatus

The larvicidal effect of the crude carbon tetrachloride, methanol and petroleum ether leaf extracts of a widely grown medicinal plant, Ocimum basilicum, against Anopheles stephensi and Culex quinquefasciatus was evaluated. Petroleum ether extract was found to be the most effective against the larvae of both mosquitoes, with LC₅₀ values of 8.29, 4.57; 87.68, 47.25 ppm and LC₉₀ values of 10.06, 6.06; 129.32, 65.58 ppm against A. stephensi and C. quinquefasciatus being observed after 24 and 48 h of treatment, respectively. The efficacy of petroleum ether was followed by that of the carbon tetrachloride and methanol extracts, which had LC₅₀ values of 268.61, 143.85; 446.61, 384.84 ppm and LC₉₀ values of 641.23, 507.80; 923.60, 887.00 ppm against A. stephensi after 24 and 48 h, respectively, and LC₅₀ values of 24.14, 17.02; 63.48, 53.77 ppm and LC₉₀ values of 295.38, 204.23; 689.71, 388.87 ppm against C. quinquefasciatus after 24 and 48 h of treatment, respectively. These extracts are highly toxic against mosquito larvae from a range of species; therefore, they may be useful for the management of mosquito larvae to control vector borne diseases.     

Aluminium(III), chromium(III) and iron(III) complexes with 5-iodouracil and 5-iodouracil-histidine and their antitumour activity

Complexes of the type [Al(HL)(OH)Cl(2)], [M(HL)(OH)(2)Cl] and [M'(HL)(L')(OH)Cl], where HL = 5-iodouracil; HL' = histidine; M = Cr(III), Fe(III) and M' = Al(III), Cr(III), Fe(III), were synthesized and characterized. The complexes are polymeric showing high decomposition points and are insoluble in water and common organic solvents. The mu(eff) values, electronic spectral bands and ESR spectra suggest a polymeric 6-coordinate spin-free octahedral stereochemistry for the Cr(III) and Fe(III) complexes. 5-Iodouracil acts as a monodentate ligand coordinating to the metal ion through the O atom of C((4)) = O while histidine through the O atom of -COO(- ) and the N atom of -NH(2) group. In vivo antitumour effect of 5-iodouracil and its complexes was examined on C(3)H /He mice against P815 murine mastocytoma. As evident from their T/C values, Cr(III) and Fe(III) complexes display significant and higher antitumour activity compared to the 5-iodouracil ligand. The in vitro results of the complexes on the same cells indicate that Cr(III) and Fe(III) complexes show higher inhibition on (3)H-thymidine and (3)H-uridine incorporation in DNA and RNA replication, respectively, at a dose of 5 microg/mL.     

Treatment of spentwash using chemically modified bagasse and colour removal studies

Studies were carried out on derivatisation of bagasse into an ion exchange material and application of this chemically modified bagasse in the treatment of distillery wastewater. It was found that CHPTAC bagasse with HCl treatment and DEAE-bagasse in its free base form were most effective in colour removal and the mechanism of colour removal indicated significant contribution of both, the conventional ion exchange and the chemical sorption.     

Biosorption of dyes using dead macro fungi: effect of dye structure, ionic strength and pH

Biosorbents prepared from dead macro fungi, namely Fomes fomentarius and Phellinus igniarius, were applied for the uptake of Methylene Blue (MB) and Rhodamine B (RB). Equilibrium isotherm data could be well described by the Langmuir and Freundlich models. Methylene Blue was found to be more adsorbable than Rhodamine B. Langmuir monolayer coverage was determined as 204.38-232.73 mg/g and 25.12-36.82 mg/g for MB and RB, respectively. Molecular structure and ionic radius of dyes were found to be responsible for differences in their uptakes. Results showed that sorption of MB increased while that of RB decreased as pH of respective dye solutions changed from 3 to 11. An increase in ionic strength also exhibited an adverse effect on dye sorption capacity. Ionic strength and pH affected the sorption of MB more as compared to the sorption of RB. The presence of carboxylic (-ve) and amino (+ve) groups in RB could explain the lower sorption of RB compared to MB.     

Complete genome sequence of Coraliomargarita akajimensis type strain (04OKA010-24)

Coraliomargarita akajimensis Yoon et al. 2007 is the type species of the genus Coraliomargarita. C. akajimensis is an obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium that was isolated from seawater surrounding the hard coral Galaxea fascicularis. C. akajimensis is of special interest because of its phylogenetic position in a genomically under-studied area of the bacterial diversity. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of a member of the family Puniceicoccaceae. The 3,750,771 bp long genome with its 3,137 protein-coding and 55 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.