Abstract

ROSSI, F. G. et al. Effect of cultivation conditions on glucose-6-phosphate dehydrogenase production by genetically modified Saccharomyces cerevisiae. Braz. J. Chem. Eng. [online]. 2009, vol.26, n.1, pp. 1-9. ISSN 0104-6632.  http://dx.doi.org/10.1590/S0104-66322009000100001.

The objective of this research was to improve Glucose-6-phosphate dehydrogenase (G6PD) production by Saccharomyces cerevisiae W303-181, which carry the plasmid YEpPGK-G6PD, by varying the following cultivation conditions: pH value (4.8, 5.7 and 6.6); inoculum concentration (0.1, 0.6 and 1.1 g/L) and initial glucose concentration (20.0, 30.0 and 40.0 g/L). The effect of those variables on G6PD production capability was studied by the application of response surface statistical analysis. The results showed that the highest G6PD production (1594.2 U/L), specific activity (1189.7 U/g_cell) and productivity (45.6 U/L.h) occurred at pH 4.8, inoculum concentration of 0.1 g/L and initial glucose concentration of 20.0 g/L, under agitation of 150 rpm at 30ºC after 36 h. In this work, the strain expressed about 21 fold more activity than the wild S. cerevisiae strain, being an attractive and promising new source of this enzyme.

Keywords : Saccharomyces cerevisiae; Fermentation; Enzyme production; Glucose-6-phosphate dehydrogenase; Strain genetically modified.