Biosynthesis and characterization of silver nanoparticles from leaf extracts of Lantana camara

Vastrad Jyoti V. and Goudar Giridhar

Green synthesis of nanoparticles is gaining a notable importance nowadays due to their eco friendly and cost effective approach. An ecofriendly and economical method for the biosynthesis of silver nanoparticles using the plant leaves of Lantana camara has been reported in the present study. Silver nanoparticles (AgNps) were prepared from the leaf extract using 50% ethyl alcohol and distilled water, the synthesis of AgNps was assertained by colour change from yellowish green to dark brown. Characterization of AgNps was done using UV-VIS spectroscopy, Particle size analysis and Scanning Electron Microscope (SEM). Both the extracts exhibited significant results for the biosynthesis of AgNps by using silver nitrate as reducing agent. These AgNps prepared from natural source may have the antimicrobial activity which can be utilized for several antimicrobial finishes in textiles.

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Media optimization for the production of a thermostable lipase from Geobacillus sp.

Bajoria Vani D. and Sabharwal Sushma G.

Geobacillus sp. is a gram positive thermophilic organism that grows optimally at 60° C. The present work describes the optimization of the culture conditions for the production of an extracellular lipase from the Geobacillus sp. Lipase production from Geobacillus sp. was maximum at pH 8.5 and 60° C temperature. Olive oil was found to be the best carbon source for inducing the production of lipase by it. The use of proteose peptone as nitrogen source enhanced lipase production maximally. Ammonium chloride, dipotassium hydrogen phosphate and potassium dihydrogen phosphate increased the production of lipase.

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Enhancement in the solubility of triclosan with Triton X-100 without affecting its antibacterial activity in Escherichia coli

Mehton Ramandeep Kaur, Ramya T.N.C. and Chhibber Manmohan

Triclosan is a non-ionic antibacterial agent that inhibits the type II fatty acid biosynthesis pathway in bacteria. It is widely used in personal care products and cosmetics, but its poor solubility in water necessitates the use of surfactants in most commercial formulations. Surfactants based on acyl chains act as fatty acid salvage sources and compromise triclosan efficacy. Thus, there is a need to formally evaluate the effect of different surfactants on the efficacy of this molecule. We examined the effect of five different surfactants namely tween-80, tween-20, triton X-100, octyl glucoside and sodium deoxycholate on triclosan solubility and IC50 in Escherichia coli K-12. Our study provides an optimized concentration range of triton X-100 (0.05 mM to 0.02 mM) that may be used to improve triclosan solubility together with 0.1 % DMSO without compromising its antibacterial potency. In contrast, tween-20 (0.2 mM) and tween-80 (0.1 mM) improve the solubility of up to 200.0 μM and 400.0 μM respectively but compromise its antibacterial activity. Octyl glucoside (30.0 mM) and sodium deoxycholate (7.0 mM) improve the solubility of triclosan up to 600.0 μM and 800.0 μM respectively but are themselves toxic to E. coli at these concentrations.

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Physico-chemical Properties of Blended Gasoline Samples produced from Khartoum Refinery in Sudan

Moh.Ezeldin, Ali M. Masaad, Abualreish M. J. A. and Alsiddig O. Ahmed

The physical and chemical properties of gasoline samples produced after Blending (BG) were studied; the samples (Tank1, Tank2, Tank3 and Tank4) were taken from Khartoum refinery (RFCC unit) in Sudan. Gasoline samples were tested according to the American Society for Testing and Materials(ASTM)1 Tests included distillation , sulfur content, density, vapor pressure, oxidation stability, cupper strip corrosion, gum existence, lead content and octane number determination by Cooperative Fuels Research CFR engine. Results obtained revealed that the physic-chemical properties of BG samples agreed well within the limits assigned by ASTM and Khartoum refinery except the motor octane number (MON)which was found to be 87, 87.9, 87.5 and 87.7 for T1, T2,T3 and T4 respectively, these values were found lower to be used as fuels of high quality internal combustion engine.

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Biosorption of Congo Red using Allium Sativum skin powder

Mohan Rao Tamtam and Basava Rao Vudata Venkata

In recent days it has been found that agriculture waste is alternate and cost effective adsorbent to replace activated carbon. On the other hand, majority of synthetic dyes currently used are highly water soluble and are objectionable at even very low concentrations. Being stable and complex, these are non biodegradable causing major environmental damage. Further, biosorption has become a promising potential alternative to conventional processes for the removal of pollutants in particular Congo Red (CR) from aqueous solutions. The present work is aimed to prove Allium Sativum Skin Powder (ASSP) as an alternative adsorbent to remove CR from waste water. The effect of various parameters like dosage, particle size, effluent concentration, temperature and pH were studied. Thermodynamic, Kinetic and Isothermal studies were conducted to ascertain the mode and mechanism of sorption process. ASSP is proven to be an effective adsorbent with the maximum adsorption capacity of 221.91 mg/g with monolayer coverage which follows pseudo second order kinetics with endothermic nature.

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Recent Developments in Composite Biosorbents and their Applications for Wastewater Treatment

Dragan Ecaterina Stela, Dinu Maria Valentina and Gargh Shankar

Heavy metals and organic matter coming from various industrial processes are recognized as very dangerous pollutants. Removing metal ions andionic dyes is a major industrial activity covering water softening to detoxification of wastewater and contaminated natural waters.This review is focused on the results reported in literature last decade regarding the preparation of novel and more efficient composite biosorbents based on polysaccharides and either inorganic fillers (zeolites, clays or magnetic nanoparticles), or synthetic polymers and on their application in the wastewater treatment.The influence of the parameters controlling the sorption process such as contact time, concentration of solute, temperature, pHhas been discussed. Sorption capacity and reusability of the composite biosorbents have been evaluated in comparison with the individual components.

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