Combined cross-linked enzyme aggregates from versatile peroxidase and glucose oxidase: Production, partial characterization and application for the elimination of endocrine disruptors

Versatile peroxidase (VP) from Bjerkandera adusta was insolubilized in the form of cross-linked enzyme aggregates (CLEA(R)s). Of the initially applied activity 67% was recovered as CLEA(R)s. Co-aggregation of VP with glucose oxidase from Aspergillus niger led to an increased activity recovery of 89%. The combined CLEA(R)s showed higher stability against H(2)O(2) and exerted VP activity upon glucose addition. The elimination of the endocrine disrupting chemicals bisphenol A, nonylphenol, triclosan, 17 alpha-ethinylestradiol and the hormone 17 beta-estradiol (10 mg L(-1) each) and the removal of their estrogenic activity by combined CLEA(R)s were tested in batch experiments. Within 10 min, the combined CLEA(R)s were able to remove all the endocrine disruptors except triclosan (residual concentration 74%). The removal of the estrogenic activity was higher than 55% for all compounds, except triclosan. A membrane reactor continuously operated with combined CLEA(R)s could almost completely remove bisphenol A (10 mg L(-1)) for 43 h. (C) 2011 Elsevier Ltd. All rights reserved

Phase behavior of the Pluronic P103/water system in the dilute and semi-dilute regimes

The detailed temperature-composition phase diagram of the P103/water system in the dilute and semidilute regions is reported here using density and ultrasound velocity measurements, differential scanning calorimetry (DSC), rheometry and dynamic (DLS) and static light scattering (SLS). These techniques allow a precise determination of the critical micellar temperature (CMT), the sphere-to-rod micellar transition temperature (GMT) and the cloud point temperature (CPT) as a function of concentration. DLS and SLS measurements were employed to gain information on unimers and aggregate sizes and on the transition from spherical-to-rod micelles. � 2009 Elsevier Inc. All rights reserved