초록

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Sucrose에 의한 재조합 Saccharomyces cerevisiae의 invertase 생성 양성을 이단계 배양을 통하여 관찰하였다. 포도당 배지에서 SUC2 유전자의 발현이 억제된 상태에서 발현배지의 sucrose 농도가 2$g/\ell$일 경우 invertase 최대 비역가는 10 units로 5$g/\ell$보다 40% 향상된 값을 보여주었다. 발현배지에서의 당의 농도변화와 invertase 발현은 서로 대응관계가 있음을 발견하였다. 초기에는 SUC2 유전자가 발현되어 invertase가 생성 분비되어서 배지중 sucrose를 포도당과 과당으로 분해하였다. 분해된 포도당의 농도가 2$g/\ell$ 이상이 되면 invertase 생성은 다시 억제되었다. 동시에 미생물에 생육에 의해 포도당 농도가 2$g/\ell$이하로 감소되면서 다시 invertase 생성이 유도되었다. 이러한 현사은 5$g/\ell$의 sucrose 배지에서 더욱 현저하게 관찰 할 수 있었다. 발현배지의 온도를 $35^{\circ}C$증가시켰을 경우 invertase 생성은 $30^{\circ}C$보다 약 1.7배만큼 증가하였다.

Abstract ▼ AI-Helper

The expression pattern of the cloned SUC2 gene in recombinant Saccharomyces cerevisiae was investigated in a two-stage culture. The recombinant yeast grown in a glucose medium where the SUC2 gene was repressed was harvested and then resuspended in a sucrose medium to induce invertase expression. The...

The expression pattern of the cloned SUC2 gene in recombinant Saccharomyces cerevisiae was investigated in a two-stage culture. The recombinant yeast grown in a glucose medium where the SUC2 gene was repressed was harvested and then resuspended in a sucrose medium to induce invertase expression. The maximum activity of 10 units was obtained in a medium containing 2 $g/\ell$ sucrose as a carbon source at $30^{\circ}C$ . The oscillatory behavior of invertase activity in response to glucose concentrations in the second stage was observed. This effect can be attributed to a series of events: invertase expression from the SUC2 gene. sucrose hydrolysis to glucose and fructose by invertase, SUC2 repression by high glucose concentration, invertase induction as a result of depletion of glucose used for the yeast growth. The invertase activity was increased by 72.5% when growth temperature changed from $30^{\circ}C$: to $35^{\circ}C$.

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