Improvement in the Thermostability of a Recombinant ß-Glucosidase Immobilized in Zeolite under Different Conditions.

ß-Glucosidase is part of the cellulases and is responsible for degrading cellobiose into glucose, a compound that can be used to produce biofuels. However, the use of the free enzyme makes the process more expensive. Enzyme immobilization improves catalytic characteristics and supports, such as zeolites, which have physical-chemical characteristics and ion exchange capacity that have a promising application in the biotechnological industry. This research aimed to immobilize by adsorption a recombinant ß-glucosidase from Trichoderma reesei, obtained in Escherichia coli BL21 (DE3), in a commercial zeolite. A Box Behnken statistical design was applied to find the optimal immobilization parameters, the stability against pH and temperature was determined, and the immobilized enzyme was characterized by SEM. The highest enzymatic activity was determined with 100 mg of zeolite at 35 °C and 175 min. Compared to the free enzyme, the immobilized recombinant ß-glucosidase presented greater activity from pH 2 to 4 and greater thermostability. The kinetic parameters were calculated, and a lower KM value was obtained for the immobilized enzyme compared to the free enzyme. The obtained immobilization parameters by a simple adsorption method and the significant operational stability indicate promising applications in different fields.

[Interactive patterns detection in family communication with adolescents]. / Detección de patrones interactivos en la comunicación de familias con hijos adolescentes.

Interactive patterns detection in family communication with adolescents. Nondistant communication is a relevant indicator for family functionality valuation. The goal of this study is to analyze this communication in order to identify specific kinds of leadership, interaction patterns and the relation between verbal and nonverbal elements in communication. The observational design exposed is an idiographic one, punctual and multidimensional, which uses field format as observation instrument. Participants were seven standardized families made up of both ancestors and an adolescent son or daughter. According to the family models analyzed, results show a predominantly democratic communication style in adults with recurrent support expressions. The sequential analysis incorporates only categories from the emitter point of view, and detects relevant sequences which show symmetric interaction between all three family members. Verbal and nonverbal channels provide complementary information. Depending on adolescents' gender different patterns in behaviour can be identified as well.