Screening for conditions of enhanced production of a recombinant beta-glucanase secreted into the medium by Escherichia coli

Spexard M, Beshay U, Risse JM, Miksch G, Flaschel E. Screening for conditions of enhanced production of a recombinant beta-glucanase secreted into the medium by Escherichia coli. BIOTECHNOLOGY LETTERS. 2010;32(2):243-248.The extracellular production of a hybrid bacterial beta-glucanase using Escherichia coli was studied by using combinations of promoters of varying strength for both a beta-glucanase as the target protein and the Kil protein as the releasing factor. Four strains with different combinations of promoter strengths were cultivated in shake-flasks on four different media to assess the cross-influence of promoter and medium in a general manner. Promoters were taken from natural as well as synthetic sequences known to exhibit either weak or strong promoter strength. By far the highest extracellular glucanase activity (> 200 U ml(-1)) was achieved when a strain harbouring the kil gene under control of a strong synthetic stationary-phase promoter and the glucanase gene under control of a strong synthetic constitutive promoter was cultivated on a complex medium mainly composed of casein peptone, yeast extract, and glycerol

Exploring the psychological rewards of a wilderness experience: an interpretive phenomenological analysis

This study was concerned with the subjective experiences of five women (N = 5) on a 10-day Scottish wilderness trip focussing on well-being and environmental perceptions. Semistructured interviews, using an ethnographic approach, were subjected to interpretative phenomenological analysis (Smith, Jarman, & Osborn, 199938. Smith , J. A. , Flowers , P. , & Larkin , M. ( 2009 ). Interpretative phenomenological analysis: Theory, method, and research. London : Sage. View all references). The group shared common positive experiences characterized by feelings of connection, aliveness, contemplativeness, self-discovery, confidence, and well-being, although some deeper emotional experiences remained ineffable. Although participants' positive experiences were tied to an intimacy with the natural environment, others expressed an additional social influence, derived from bonds formed within the group. These findings are important for a better understanding of the effects that such wilderness experiences can have on people's psychological well-being and the development of positive people–environment relationships