Quantitative determination of gibberellins by high performance liquid chromatography from various gibberellins producing Fusarium strains

High performance liquid chromatographic (HPLC) method was developed for analysis of seven gibberellins, i.e., GA₃, GA₄, GA₇, GA₃ methyl ester, GA₇ methyl ester 3,13 diacetate, GA₇ methyl ester, and fusaric acid, using an isocratic system. Method was used for estimation of gibberellins from different Fusarium strains. Gibberellins were extracted from 28 strains of Fusarium, out of which six strains of Fusarium were isolated from soil of different parts of India and 22 strains were procured from the Indian Type Culture Collection, Indian Agricultural Research Institute, New Delhi. Extracts were analyzed for qualitative and quantitative estimation of gibberellins by thin layer chromatography and HPLC, respectively. On the basis of quantitative analysis of produced gibberellins by HPLC, they were categorized as low, moderate, and high gibberellin producing strain. For the first time, Fusarium solani was also reported as high GA₃ producing strain.     

Dynamics of toxic heavy metals in different compartments of a highly urbanized closed aquatic system

This paper deals with the dynamics of chromium, nickel, copper and lead among the different components namely water, surface sediments, submerged and free floating macrophytes and fish of the twin manmade lakes, Upper and Lower lakes, of Bhopal (M.P., India). Some basic parameters of water and sediment have also been studied. The basin of the lake system is densely populated and the water is used for various purposes including drinking. Ni and Pb along with nitrate in both lakes are significantly higher than the drinking water quality criteria of USEPA. The concentration of the metals in the sediments is noticeably higher than that present in the adjoining rock, particularly Ni and Pb. There is a significant uptake of metals by the macrophytes (Eichhornia crassipes and Hydrilla verticillata) and fish (Labeo rohita and Oreochromis niloticus) mainly in summer. The fish of Lower lake (O. niloticus) is unfit for human consumption. The data have been statistically treated. Principle component analysis and cluster analysis were performed to define the origin of metals and to assess the relationship among the sites. Overall the Lower lake is more polluted than the Upper lake. In aggregate, the lake system is under an environmental stress due to certain practices.     

Possible maternal offloading of metals in the plasma,uterine and capsule fluid of pregnant ragged-tooth sharks (Carcharias taurus) on the east coast of South Africa

Environmental Science and Pollution Research - We studied the possible metal offloading onto the progeny of three pregnant female ragged-tooth sharks (Carcharias taurus) (C. taurus). The presences...     

Efficiency of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from contaminated soil

This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil.     

Removal of Cr(VI) onto Ficus carica biosorbent from water

The utilization of sustainable and biodegradable lignocellulosic fiber to detoxify the noxious Cr(VI) from wastewater is considered a versatile approach to clean up a contaminated aquatic environment. The aim of the present research is to assess the proficiency and mechanism of biosorption on Ficus carica bast fiber via isotherm models (Langmuir, Freundlich, Temkin, Harkin’s–Jura, and Dubinin–Radushkevich), kinetic models, and thermodynamic parameters. The biomass extracted from fig plant was characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. To optimize the maximum removal efficiency, different parameters like effect of initial concentration, effect of temperature, pH, and contact time were studied by batch method. The equilibrium data were best represented by the Langmuir isotherm model, and the maximum adsorption capacity of Cr(VI) onto biosorbent was found to be 19.68 mg/g. The pseudo-second-order kinetic model adequately described the kinetic data. The calculated values of thermodynamic parameters such as enthalpy change (?H ⁰), entropy change (?S ⁰), and free energy change (?G ⁰) were 21.55 kJ/mol, 76.24 J/mol?K, and ?1.55 kJ/mol, respectively, at 30 °C which accounted for spontaneous and endothermic processes. The study of adsorbent capacity for Cr(VI) removal in the presence of Na⁺, Mg²⁺, Ca²⁺, SO ₄ ^2? , HCO ₃ ^? and Cl^? illustrated that the removal of Cr(VI) increased in the presence of HCO^3? ions; the presence of Na⁺, SO ₄ ^2? or Cl^? showed no significant influence on Cr(VI) adsorption, while Ca²⁺ and Mg²⁺ ions led to an insignificant decrease in Cr(VI) adsorption. Further, the desorption studies illustrated that 31.10 % of metal ions can be removed from an aqueous system, out of which 26.63 % of metal ions can be recovered by desorption in first cycle and the adsorbent can be reused. The results of the scale-up study show that the ecofriendly detoxification of Cr(VI) from aqueous systems was technologically feasible.     

Effect of Diffusiophoresis and Thermophoresis on the Overall Particle Collection Efficiency of Spray Droplet Scrubbers

The overall particle collection efficiencies of spray scrubbers using monodisperse droplets of 100,500, and 1000 microns diameter were calculated for the cases of evaporating and condensing droplets. The properties of the gas at the inlet to the spray scrubber were maintained constant at 150°F, 100% relative humidity, and 1 atmosphere pressure. At the liquid entrance to the spray scrubber, the water droplet temperature was 50° F for the condensing case and 180° F for the evaporating case. The liquid to gas flow rate ratio for all the calculations was held constant at 4 gal/1000 acf. The gas velocity in the co-current spray tower was 1 ft/sec in the downwind direction. The calculation results show that for the particles in the 0.01 to 10 Mm diameter range, the overall spray scrubber particle collection efficiency is greater with the cooler 50°F water (condensing case) than with the warmer 180°F water (evaporating case). The effect of diffusiophoresis and thermophoresis is noticeable for all the water droplet sizes considered, but is more significant for the larger water droplets. This greater effect for the larger water droplets compared to the smaller droplets is due to the longer existence of the temperature and water vapor concentration gradients between the water droplets and the surrounding gas.     

Adaptation, validation and application of the chemo-thermal oxidation method to quantify black carbon in soils

The chemo-thermal oxidation method at 375 °C (CTO-375) has been widely used to quantify black carbon (BC) in sediments. In the present study, CTO-375 was tested and adapted for application to soil, accounting for some matrix specific properties like high organic carbon (≤39%) and carbonate (≤37%) content. Average recoveries of standard reference material SRM-2975 ranged from 25 to 86% for nine representative Swiss and Indian samples, which is similar to literature data for sediments. The adapted method was applied to selected samples of the Swiss soil monitoring network (NABO). BC content exhibited different patterns in three soil profiles while contribution of BC to TOC was found maximum below the topsoil at all three sites, however at different depths (60-130 cm). Six different NABO sites exhibited largely constant BC concentrations over the last 25 years, with short-term (6 months) prevailing over long-term (5 years) temporal fluctuations.     

Phytoplankton community structure in relation to environmental factors from the New Mangalore Port waters along the southwest coast of India

Seasonal and spatial phytoplankton distribution in relation to environmental factors was investigated in New Mangalore Port, a major port along the west coast of India. A well-mixed water column characterized the non-monsoon seasons, whereas it was weakly stratified during monsoon. Water quality index (TRIX) scores indicated good water quality except during pre-monsoon (inner zone surface) and monsoon (near bottom waters). Surface abundance of tychopelagic diatoms (Paralia sulcata, Melosira nummuloides, Cylindrotheca closterium, and Nitzschia sigma) was higher during non-monsoon seasons. Certain centric diatoms, e.g., Leptocylindrus danicus, P. sulcata, and Rhizosolenia imbricata, dominated during pre-monsoon (inner zone) and positively correlated with TRIX. High Skeletonema costatum and dinoflagellate abundance during the monsoon season coincided with high nutrient concentrations. Five potential toxic and fourteen harmful/bloom forming algal species were encountered at abundances below the level that can be considered as harmful to the ecosystem. In addition to a baseline database, this study highlights the potential use of certain diatom species as indicators of hydrography and water quality for monitoring dynamic coastal marine ecosystems.     

Groundwater geochemical facie: implications of rock-water interaction at the Chamba city (HP), northwest Himalaya,India

Environmental Science and Pollution Research - The present study describes geochemical facie and implications of rock-water interaction at the groundwater of Chamba city. The influence of rock...     

A new approach for estimating the phytotoxicity limits

A pot experiment was carried out on a Typic ustipsamment to study the effect of Cd concentration on the yield of wheat (Triticum aestivum) and soybean (Glycine max). Cd levels taken were 1, 5, 10, 20, 40, 80, and 160 g g^-1 of soil. Three different statistical procedures were employed to evaluate the phytotoxicity limits. The non-linear regression technique was found to be more effective in calculating C ₀ (threshold concentration) and C ₁₀₀ (toxic concentration) in comparison to Cate and Nelson (1971) and Beckett and Davis (1977) procedures. This technique was unaffected by the nature of the distribution of the data and did not require any initial value of concentration as a starting point.