| Summary: | Made available in DSpace on 2014-12-17T15:41:42Z (GMT). No. of bitstreams: 1
SusanIGM_Capa_ate_Cap2.pdf: 775391 bytes, checksum: bff1b25a943d2e8086f1be8fb59414cc (MD5)
Previous issue date: 2007-03-02 === Enzymes have been widely used in biosynthesis/transformation of organic compounds in substitution the classic synthetic methods. This work is the first writing in literature of enzymatic synthesis for attainment the biossurfactants, the use glucose sucrose, ricinoleic acid e castor oil as substratum, and as biocatalyst, used immobilized lipase Thermomyces lanuginose, Rhizomucor miehei and the Candida antarctica lipase B; alkaline protease and neutral protease from Bacillus subtillis and yeast Saccharomyces cerevisiaeI. The analysis of HPLC (high performance liquid chromatography) showed that highest conversions were reached of used the alkaline protease from Bacillus subtillis. Laboratory tests, to evaluate the applicability, indicated that the produced biosurfactantes had good stability in presence of salts (NaCl) and temperature (55 e 25?C), they are effective in the reduction of the superficial tension and contac angle, but they have little foaming capacity, when compared with traditional detergents. These results suggest that the prepared surfactants have potential application as wetting agent and perforation fluid stabilizer === Enzimas t?m sido largamente utilizadas em ma??es de compostos org?nicos em substitui??o aos m?todos sint?ticos cl?ssicos. Esta disserta??o de mestrado ? o primeiro relato escrito em literatura de s?ntese enzim?tica para obten??o de biosurfactantes utilizando como substratos glicose, ?cido ricinol?ico e ?leo de mamona, e como biocatalizador, foram empregadas lipases imobilizadas (Thermomyces lanuginosa, Rhizomucor miehei e Candida antarctica B), proteases
(Bacillus subtillis alcalina e Bacillus subtillis neutra) e levedura (Saccharomyces cerevisiae). A an?lise por CLAE (cromatografia l?quida de alta efici?ncia) mostrou que
maiores convers?es foram alcan?adas pelo uso da Bacillus subtillis alcalina. Testes de laborat?rio, para avaliar sua aplicabilidade, indicaram que os biosurfactantes produzidos apresentam boa estabilidade em presen?a de NaCl e temperaturas de 55 e 25?C, s?o efetivos na redu??o da tens?o superficial e ?ngulo de contato, mas possuem pouca capacidade espumante, quando comparados aos detergentes tradicionais. Estes resultados sugerem que os surfactantes obtidos t?m potencial aplica??o como agente de molhabilidade e estabilizador de fluidos de perfura??o === 2020-01-01
|
|---|
