Hydrocarbons biodegradation by activated sludge bacteria in the presence of natural and synthetic surfactants.

Fuels, such as diesel oil, can have a substantial impact on the microbial equilibrium of activated sludge and have a negative influence on work of wastewater treatment plant. The primary objective of the research was to examine the possibility of using the surfactants to improve pollutants biodegradation by bacteria from activated sludge. The results showed that the addition of rhamnolipids allows to increase the hydrocarbon biodegradation from 47% up to 75% in the cultures inoculated with the consortium.

Equilibrium studies of cobalt(II) extraction with 2-pyridineketoxime from mixed sulphate/chloride solution.

In present paper the equilibrium of cobalt extraction with 1-(2-pyridyl)tridecan-1-one oxime from the chloride/sulphate solutions was studied. The presented results indicated that extraction depends on a number of process variables, including the pH, metal and Cl concentration in the aqueous feed, and concentration of the oxime in the organic phase. The created cobalt-complexes with the 2-pyridine ketoxime were stable and only concentrated HCl was found to be a suitable stripping agent for coordinated metal.

Best conditions for biodegradation of diesel oil by chemometric tools.

Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems.

The influence of rhamnolipids on aliphatic fractions of diesel oil biodegradation by microorganism combinations.

Twelve different bacteria-yeast combinations were tested for determination of their ability to biodegrade diesel oil. The cell surface properties of the bacterial and yeast strains were correlated with the type of carbon source used in the experiments. The highest biodegradation of diesel oil after 7 days was obtained for the following combinations: Aeromonas hydrophila MR4-Yarrowia lipolytica EH 56 (87 %) and Xantomonas maltophila MRP7-Candida maltosa EH15 (90 %).

Cell surface properties of Pseudomonas stutzeri in the process of diesel oil biodegradation.

Pseudomonas stutzeri, isolated from crude oil-contaminated soil, was used to degrade diesel oil. Of three surfactants, 120 mg rhamnolipids 1(-1) significantly increased degradation of diesel oil giving 88% loss after 14 days compared to 54% loss without the surfactant. The system with rhamnolipids was characterised by relatively high particle homogeneity.

Uptake of Hydrocarbon by Pseudomonas fluorescens (P1) and Pseudomonas putida (K1) Strains in the Presence of Surfactants: A Cell Surface Modification.

The objective of this research was the evaluation of the effects of exogenous added surfactants on hydrocarbon biodegradation and on cell surface properties. Crude oil hydrocarbons are often difficult to remove from the environment because of their insolubility in water. The addition of surfactants enhances the removal of hydrocarbons by raising the solubility of these compounds.

Modification of cell surface properties of Pseudomonas alcaligenes S22 during hydrocarbon biodegradation.

Biodegradation of water insoluble hydrocarbons can be significantly increased by the addition of natural surfactants one. Very promising option is the use of saponins. The obtained results indicated that in this system, after 21 days, 92% biodegradation of diesel oil could be achieved using Pseudomonas alcaligenes.

Biodegradation of diesel/biodiesel blends by a consortium of hydrocarbon degraders: effect of the type of blend and the addition of biosurfactants.

Biodegradation experiments for diesel/biodiesel blends in liquid cultures by-petroleum degrading microbial consortium showed that for low amendments of biodiesel (10%) the overall biodegradation efficiency of the mixture after seven days was lower than for petroleum diesel fuel. Preferential usage of methyl esters in the broad biodiesel concentration range and diminished biodegradation of petroleum hydrocarbons for 10% biodiesel blend was confirmed. Rhamnolipids improved biodegradation efficiency only for blends with low content of biodiesel.

Influence of solvent and counter ion on copper complexes with N-alkyl-pyridine-2-carboxamides as studied by electrospray ionization mass spectrometry.

The interactions of copper(II) with N-alkyl-pyridine-2-carboxamides (M) were studied by electrospray ionization mass spectrometry. The influence of solvent and counter ion (Cl-, ClO4-) on the type of ions (complexes) observed was discussed. By cone voltage increase, the fragmentation "in source" of the ions discussed was achieved.

[The significance of cardiac symptoms in patients referred to pediatric cardiology outpatient clinics].

Objective: To determine the significance of cardiac symptoms in patients referred to paediatric cardiology outpatient clinics.

Material And Methods: All patients above l month of age referred to paediatric cardiac outpatient clinics between 01-Apr-2004 and 31-Dec-2004. Data was collected prospectively in Internet data base.

Mass spectrometric decompositions of copper complexes with esters and amides of nicotinic acid.

Mass spectrometric decompositions of complexes of nicotinic acid esters and amides with copper are discussed. Liquid secondary ion mass spectrometry (LSIMS) was used as an ionisation technique and metastable ion spectra were recorded by using B/E linked scans. The fragmentation pathways consist mainly of the loss of one ligand molecule and also the cleavage of amide or ester bonds.