ABSTRACT

A 13 kDa Schistosoma mansoni tegumental antigen (Sm13) was cloned and expressed in Escherichia coli. The fermentation product of 55 kDa corresponds to the maltose binding protein-recombinant Sm13 fusion protein (MBP-rSm13). The growth conditions for maximum IPTG inducible MBP-rSm13 production was investigated by examining the following parameters: innoculum size, agitation, temperature of induction and concentration of the inducer, IPTG. The maximum MBP-rSm13 production was achieved by two steps-fermentation. First, the recombinant strain was cultivated in a 37°C orbital shaker, at 160 rpm, for 3 hours. The MBP-rSm13 was then induced by adding 0.3 mM IPTG and placing the culture in a 28°C orbital shaker for 2 hours. Under these conditions the MBPrSm13 production yield was approximately 50% of total intracellular proteins and the degradation by bacterial intracellular proteases seemed to be minimized. The plasmid stability was also studied during the fermentation of the Sm13-expressing E. coli in non induced and induced conditions. In both conditions there was a slightly plasmid loss before induction, however after the addition of IPTG the loss was increased. The rate of plasmid loss was 5.5 and 13.5 before and after IPTG induction respectively.Abbreviations LB, Lurian-Bertani medium; PBS, phosphate-buffered saline pH 7.4; IPTG, isopropil-6-D-thiogalactoside; MBP-rSm13, maltose binding proteinrecombinant Sm13 fusion protein; SDS-PAGE, sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

RESUMOEsta pesquisa bibliográfica tem o objetivo de contribuir com os estudos relacionados a temática da educação e espiritualidade. Embora pareça existir uma tensão antagônica entre a educação e espiritualidade, a mesma se dá pelo entendimento do que significa a espiritualidade. Aqui, pretenderemos analisá-la do ponto de vista da categoria pedagógica capaz de contribuir no desenvolvimento do homem no sentido de torná-lo capaz de situar-se no mundo como agente ativo, consciente da realidade opressora que lhe envolve. O referencial teórico que fundamenta a ideia é a pedagogia de Paulo Freire. Entendemos que em sua pedagogia, além dos traços teóricos do marxismo, é possível identificar traços de um modelo de espiritualidade, não alienante, que não romantiza o cotidiano opressor do homem, mas que lhe permite situar-se no mundo de forma consciente e humanizador. PalavRa-chavEEducação, espiritualidade, liberdade, conscientização e humanização.

This work describes the partition of a Schistosoma mansoni tegumental antigen produced by a recombinant Escherichia coli strain using an aqueous two-phase system composed of polyethylene glycol (PEG) and potassium phosphate. The effects of the polymer molecular weight, tie line length and pH on antigen partitioning were investigated. The detection of the antigen in both phases were determined by ELISA. The system composed of PEG 3550 (19.7% w/w) and potassium phosphate (17.7% w/w) led to a yield of 59% and an antigen puri®cation factor of 3 in the PEG-rich phase. It was observed that the antigen partition in ATPS was strongly affected by the pH value and tie line length. In addition, it was possible in a single step, to remove the cell debris, that precipitated at the interface of the system.