A comparative SEM study of smear layer removal by detergents and EDTA on the root surface

The present study performed an SEM evaluation of the efficiency of the following detergents on smear layer removal on the root surface: sodium lauryl sulphate, Plax, castor oil, and EDTA 24%. Sodium lauryl sulphate did not remove the smear layer and showed the worst results of all detergents tested. Plax and castor-oil detergents showed similar results represented by partial removal of the smear layer; these results were better than those obtained in the control (physiologic serum) and sodium lauryl sulphate groups. Neutral EDTA 24% was the most efficient detergent for smear layer removal.

Counterion effects on the structure and solubilization properties of anionic detergents. Role of hydrophobic cations in stabilizing micelles and attenuating their solvent properties

A series of alkyl sulfate detergents has been investigated in the presence of the cations Na +, methylviologen(2+) (MV 2+), 4-(cyanomethyl)pyridinium(1+) (CMP +), and tetramethylammonium (TMA +). The binding of these ions to the aqueous micellar assemblies has been measured through studies of luminescence quenching with the extramicellar probe, RuL 34-, where L = 4,4′-dicarboxy-2,2′-bipyridine. A general comparison of the alkyl sulfate aggregates with the nonquenching cations Na + and TMA + shows that the latter ion reduces the critical micelle concentration but at the same time depresses the ability of the detergent assemblies to bind or solubilize the hydrophobic quencher cations MV 2+ or CMP +. The reduced binding ability of the TMA + aggregates compared to that of the corresponding Na + soaps shows up largely in the form of a reduced favorable ΔS° for the solubilization in the case of the former. The results are in accord with a picture of the TMA + micelle as being more stable and more disordered than the corresponding assembly with Na + as the counterion. © 1989 American Chemical Society.

Stability of a Lipase Extracted from Seeds of Pachira aquatica in Commercial Detergents and Application Tests in Poultry Wastewater Pretreatment and Fat Particle Hydrolysis

A protein extract containing a plant lipase from oleaginous seeds of Pachira aquatica was tested using soybean oil, wastewater from a poultry processing plant, and beef fat particles as substrate. The hydrolysis experiments were carried out at a temperature of 40°C, an incubation time of 90 minutes, and pH 8.0-9.0. The enzyme had the best stability at pH 9.0 and showed good stability in the alkaline range. It was found that P. aquatica lipase was stable in the presence of some commercial laundry detergent formulations, and it retained full activity up to 0.35% in hydrogen peroxide, despite losing activity at higher concentrations. Concerning wastewater, the lipase increased free fatty acids release by 7.4 times and promoted the hydrolysis of approximately 10% of the fats, suggesting that it could be included in a pretreatment stage, especially for vegetable oil degradation.

Effects of biodegradable detergents in the accumulation of lipofuscin (age pigment) in gill and liver of two neotropical fish species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seed lipases: sources, applications and properties - a review

This paper provides an overview regarding the main aspects of seed lipases, such as the reactions catalyzed, physiological functions, specificities, sources and applications. Lipases are ubiquitous in nature and are produced by several plants, animals and microorganisms. These enzymes exhibit several very interesting features, such as low cost and easy purification, which make their commercial exploitation as industrial enzymes a potentially attractive alternative. The applications of lipases in food, detergents, oils and fats, medicines and fine chemistry, effluent treatment, biodiesel production and in the cellulose pulp industry, as well as the main sources of oilseed and cereal seed lipases, are reviewed.

Effects of exposition to polluted environments on blood cells of the fish Prochilodus lineatus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Wettability of Aqueous Rhamnolipids Solutions Produced by Pseudomonas aeruginosa LBI

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rhamnolipids and PHAs: Recent reports on Pseudomonas-derived molecules of increasing industrial interest

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isolation and characterization of latent and active polyphenoloxidase in BRS Clara (CNPUV 154-147 x Centennial seedless) and BRS Morena (Marroo seedless x Centennial seedless) seedless table grapes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of Sonication on the Thermotropic Behavior of DODAB Vesicles Studied by Fluorescence Probe Solubilization

The effect of sonication on fluorescence probe solubilization in cationic vesicles of dioctadecyldimethylammonium bromide (DODAB) was investigated by steady-state fluorescence of pyrene (Py), trans-diphenylpolyenes-diphenylbutadiene (DPB), diphenylhexatriene (DPH), and their corresponding 4,4'-dialkyl derivatives 4B4A and 4H4A fluorescence probes. The data indicate that sonication affects the bilayer polarity, the melting temperature (T (m)), and the cooperativity of the melting process due to changes in vesicle morphology. The effect of temperature on the fluorescence intensity and yielding I broken vertical bar(f) and anisotropy < r > shows that the ionizable probes 4B4A and 4H4A are solubilized close to the vesicle interfaces, whereas the non-ionizable DPH and DPB are deeper in the bilayers. Py solubilization indicates that sonicated vesicles exhibit less densely packed bilayers.

Influence of domestic sewage leakage on the collapse of tropical soils

In the studied region, 35% of the soil collapses are related to leakage from sewage ducts. The paper describes the soils from this part of Brazil and a series of laboratory tests undertaken using water and domestic sewage fluid as the wetting agents. It is considered that the presence of soaps and detergents as recorded by the sodium concentration facilitates the densification of the soils and hence has a major effect on the surface settlement/collapse.

Extracellular tannase from Emericella nidulans showing hypertolerance to temperature and organic solvents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Triton X-100 solubilized bone matrix-induced alkaline phosphatase

1. 1. Solubilized and membrane-bound alkaline phosphatase showed Michaelis-Menten behavior in a wide range of different substrate concentrations. 2. 2. Membrane-bound alkaline phosphatase has a molecular weight of 130,000 and its minimum active configuration comprises two identical subunits of about 65,000. 3. 3. The two forms of the enzyme behave similarly with respect to NaCl, urea and guanidine HCl. 4. 4. Catalytic groups have pK values of about 8.5 and 9.7 for both membrane-bound and solubilized enzyme. © 1987.