Naslov
Effects of solvent hydrophobicity and HLB-values of surfactants on lipase activity in an emulsion system

Autori
Giacometti, Jasminka ; Milin, Čedomila ; Cecić-Vidoš, Maja

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Biotechnology 2000, The World Congress on Biotechnology, 11th International Biotechnology Symposium and Exibition, Vol.4 / - Frankfurt : Deutsche Gesellschaft für chemisches Apparatewesen (DECHEMA), 2000, 422-423

Skup
Biotechnology 2000, The World Congress on Biotechnology, 11th International Biotechnology Symposium and Exibition

Mjesto i datum
Berlin, Njemačka, 03.09.2000. - 08.09.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
emulsion system; microemulsions; lipase-catalysed hydrolysis; log P

Sažetak
Introduction: The lipase catalysis in hydrated reversed micelles or W/O microemulsions exhibit high activity in these systems. The model reaction lipase catalyzed hydrolysis of triglycerides (olive oil) in an emulsion, microemulsion1, 2 and solvent system were chosen for the determination of lipase activity based on different nonionic surfactants, such as sorbitanmonolaurate (Span 20) and sorbitantrioleate (Span 85). The effects of surfactants and organic solvents3-6, versus log P value on activity of 1, 3-specific lipase from Aspergillus niger in microemulsions were investigated. Material and Methods: Lipase catalyzed hydrolysis of olive oil in an emulsion system was carried out with 70% olive oil concentration, 6.41 mg/ml lipase from Aspergillus niger at 37oC, pH 6.0 at 110 rpm, in a two-phase solvent system in a batch stirrer-tank reactor (BSTR). The assay of enzyme reaction measurement with the pH-stat method. In all experiments W0 value was 21. The hidrophilic-lipophilic balance (HLB values) is 8.6ą1.0 for sorbitanmonolaurate, and 1.8ą1.0 for sorbitantrioleat. The experiments were made with tested solvents of log P from close to 4.0, but with different functional groups. Results: Solvent hydrophobicity is related to various biocatalytic activities5. Changing the system hydrophobicity, by using different solvents had an affect on the equilibrium. Sorbitanmonolaurate and sorbitantrioleate enhanced lipase activity in direction of hydrolysis reaction in an emulsion system. The tested organic solvents, which were added to the emulsion system, decreased lipase activity, when compared with the system without organic solvents. The highest reaction rates were obtained in nonpolar tested solvents. Sorbitantrioleate showed unexpected results i.e. optimal activity was reached in the presence of acetone. The use of sorbitanmonolaurate increased lipase activity in nonpolar solvents. Conclusion: The nonionic surfactants exhibit higher lipase activity in the emulsion system when compared with the system without surfactants. The comparison of the used nonionic surfactants, sorbitan fatty acid esters, in the microemulsion system, showed that lipase activity is higher in the presence of n-hexane and sorbitanmonolaurate in examined reaction condition. References: 1. Skagerlind, P. and Holmberg, K., J.Dispersion Sci.Technol., 15(3) (1994) 317 2. Hossain, M.J., Takeyama, T., Hayashi, Y., Kawanishi, T., Shimizu, N., Nakamura, R., J.Chem.Technol.Biotechnol., 74(59 (1999) 423 3. Laane, C., Boeren, S., Vos, K. and Veeger, C., Biotechnol. Bioeng. 28 (1987) 417 4. Ortiz, G.M.D., Martins, R.C., Rocha, W.L. and Dias, A.P., Biotechnol.Appl.Biochem. 26 (1997) 31 5. Zaks, A. and Klibanov, A.M., J.Biol.Chem. 263 (1988) 3194 6. Ross A.C., Bell, G., Halling, P.J., J.Mol.Catal.B.Enzymatic 8(4-6) (2000) 183

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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