A commercial lipase (E.C. 3.1.1.3) from Thermomyces lanuginosus was studied in order to assess its interaction with commercial nonionic (Findet Ò 1214N/16, Findet 1214N/23 and Glucopon Ò 650) and anionic (linear alkylbenzene sulphonate; LAS) surfactants, as well as the cleaning action exerted by the enzyme on hard surfaces. Nonionic surfactants seem to prevent or delay enzyme penetration at the interface, thereby decreasing lipase activity. Notably, no inhibitory effect of the anionic surfactant LAS on lipase action was found, higher conversions being achieved after 20 min of enzymatic hydrolysis in the presence of this surfactant than in its absence. A device for testing detersive performance, the so-called bath-substrateflow, was used in washing experiments with the lipase at different temperatures with or without surfactant. Employing two different oily stains (tributyrin and triolein), it was found that the lipase by itself increases detergency significantly, preventing the subsequent redeposition of the removed dirt. Expressions relating detersive efficiency to lipase concentration and temperature were obtained using ''Statistical Design of Experiments'' methodology.

One of the most studied approaches in solubilization of insoluble phosphates is the biological treatment of rock phosphates. In recent years, various techniques for rock phosphate solubilization have been proposed, with increasing emphasis on application of P-solubilizing microorganisms. The P-solubilizing activity is determined by the microbial biochemical ability to produce and release metabolites with metal-chelating functions. In a number of studies, we have shown that agro-industrial wastes can be efficiently used as substrates in solubilization of phosphate rocks. These processes were carried out employing various technologies including solid-state and submerged fermentations including immobilized cells. The review paper deals critically with several novel trends in exploring various properties of the above microbial/agro-wastes/rock phosphate systems. The major idea is to describe how a single P-solubilizing microorganism manifests wide range of metabolic abilities in different environments. In fermentation conditions, P-solubilizing microorganisms were found to produce various enzymes, siderophores, and plant hormones. Further introduction of the resulting biotechnological products into soil-plant systems resulted in significantly higher plant growth, enhanced soil properties, and biological (including biocontrol) activity. Application of these bio-products in bioremediation of disturbed (heavy metal contaminated and desertified) soils is based on another important part of their multifunctional properties.

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The present work analyzes the effect of incorporating a lipolytic enzyme (Lipolase ® 100L) into detergent formulas for washing fatty soils on hard surfaces. The experimental device, which is called a "bath-substrate-flow" device, uses a continuous flow on a substrate (glass spheres) soiled with triolein. Washing tests were done using only the enzyme and changing both its concentration and the temperature of the process. The results showed that, in the presence of lipase, soil removal was achieved through three consecutive mechanisms: (i) fundamental removal of the soil by the bath flow through the experimental device; (ii) emulsion of the soil in the washing medium; and (iii) enzymatic hydrolysis of the dispersed soil. Different commercial surfactants were used, and detergency was evaluated in the absence and presence of lipase. The use of surfactant formulas with the lipolytic enzyme showed a positive effect of the enzyme on the detergency values registered with the fatty alcohol ethoxylate surfactants Findet ® 10/15 and Findet 1214N/23, and with the anionic surfactant linear alkylbenzene sulfonate. The commercial surfactants Glucopon ® 600, Glucopon 650, Findet 10/18, and Findet Q/21.5NF alone each presented high detergency values for fatty soils, and the effect of the incorporation of the lipase was not significant.Paper no. S1493 in JSD 9, 83-90 (Qtr. 1, 2006).