title: beta-Xylosidase recovery by reversed micelles. Use of cationic surfactant.
abstract: beta-Xylosidase, an enzyme produced by Penicillium janthinellum fungus, was prepurified by fractionated precipitation with ethanol and extracted by reversed micelles of N-benzyl-N-dodecyl-N-bis(2-hydroxyethyl) ammonium chloride (BDBAC) cationic surfactant. A 2(5-1) fractional factorial design was employed to evaluate the influence of the following factors on the enzyme extraction: pH (A), conductivity (B), surfactant concentration (C), cosolvent concentration (D) and temperature (E). A statistical analysis of the results revealed that, of the five variables studied, pH, surfactant concentration, and temperature had significant main effects (p < 0.05) on the recovery of beta-xylosidase (Y). However, the interactions between pH and temperature, conductivity and cosolvent concentration, conductivity and temperature, BDBAC concentration and temperature also had significant influences. A first-order model (R2 = 0.98) expressed by the equation Y = 7.73 - 5.55A - 0.67B + 3.49C - 0.41D + 5.26E + 2.05AB - 3.26AC + 0.96AD - 7.07AE - 3.93BD - 2.19BE + 0.99CD + 0.78CE was proposed to represent the enzyme recovery as a function of the effects that were really significant. This model predicts a recovery value of about 40%, which is similar to that obtained experimentally (39.5%).
authors.affiliation: Department of Biotechnology/FAENOUIL, Lorena/SP, Brazil.
authors.forename: F A
authors.initials: FA
authors.lastname: Hasmann
authors.forename: A
authors.initials: A
authors.lastname: Pessoa
authors.forename: I C
authors.initials: IC
authors.lastname: Roberto
mesh_terms: D001548:Benzalkonium Compounds; D002412:Cations; D002482:Cellulose; D005591:Chemical Fractionation / Q000379:methods; D011232:Chemical Precipitation; D008823:Micelles; D010407:Penicillium / Q000201:enzymology; D013501:Surface-Active Agents; D014995:Xylosidases / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D001548:Benzalkonium Compounds; D002412:Cations; D008823:Micelles; D013501:Surface-Active Agents; C013850:benzoxonium chloride; D002482:Cellulose; C027433:bagasse; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase