Ensaio de estética à maneira de um Prólogo

O ensaio a seguir trata da concepção de estética que Ortega y Gasset articula a partir da noção de metáfora. Destaca-se sua ênfase na noção de objeto estético, autônomo, divorciado do sujeito artista e suas intenções. Trata-se de uma refinada, ainda que breve, articulação que define a arte como espaço de um agenciamento complexo entre o objeto e o humano

Specific growth rate governs AOX1 gene expression, affecting the production kinetics of Pichia pastoris (Komagataella phaffii) P-driven recombinant producer strains with different target gene dosage

The P-based expression system is the most widely used for producing recombinant proteins in the methylotrophic yeast Pichia pastoris (Komagataella phaffii). Despite relevant recent advances in regulation of the methanol utilization (MUT) pathway have been made, the role of specific growth rate (µ) in AOX1 regulation remains unknown, and therefore, its impact on protein production kinetics is still unclear. The influence of heterologous gene dosage, and both, operational mode and strategy, on culture physiological state was studied by cultivating the two P-driven Candida rugosa lipase 1 (Crl1) producer clones. Specifically, a clone integrating a single expression cassette of CRL1 was compared with one containing three cassettes over broad dilution rate and µ ranges in both chemostat and fed-batch cultivations. Chemostat cultivations allowed to establish the impact of µ on the MUT-related MIT1 pool which leads to a bell-shaped relationship between µ and P-driven gene expression, influencing directly Crl1 production kinetics. Also, chemostat and fed-batch cultivations exposed the favorable effects of increasing the CRL1 gene dosage (up to 2.4 fold in q ) on Crl1 production with no significant detrimental effects on physiological capabilities. P-driven gene expression and Crl1 production kinetics in P. pastoris were successfully correlated with µ. In fact, µ governs MUT-related MIT1 amount that triggers P-driven gene expression-heterologous genes included-, thus directly influencing the production kinetics of recombinant protein

Efecte de la velocitat específica de creixement en la producció de Lip-1 de Candida rugosa en Pichia pastoris sota l'efecte del promotor AOX1

En aquest estudi s'analitza l'efecte de la velocitat específica de creixement (μ) en un bioprocés en el qual el llevat metilotròfic Pichia pastoris expressa la lipasa 1 de Candida rugosa (CRL1 ) sota la regulació del promotor PAOX1. S'ha estudiat l'efecte sobre la velocitat específica de consum de substrat (qs) o la velocitat específica de síntesi de producte (qp). Aquest estudi es duu a terme mitjançant fermentacions en "fed-batch" mantenint la μ constant gràcies a una limitació de la font de carboni. S'ha observat una relació lineal entre la μ i la qs, mentre que la qp, per contra, presenta un màxim (qp = 588 U · g DCW -1 · h-1) a una μ mitjana de 0,053 h-1. Com a hipòtesi, es creu que aquest fet pot estar relacionat amb l'estrès cel·lular