재조합 효모 세포의 고농도배양을 통한 섬유소와 자일란 분해효소 유전자의 동시 과발현 = Simultaneous Overpexpression of Genes Encoding Cellulose- and Xylan-Degrading Enzymes through High Density Culture of a Recombinant Yeast Cell

다국어 초록 (Multilingual Abstract)

For the coexpression of endoxylanase and endoglucanase genes in yeast Saccharomyces cerevisiae, the genes were separately inserted downstream of the yeast ADH1 promoters, resulting the plasmid pAGX3 (9.83 kb). In the batch culture on YPD medium of the yeast transformant, S. cerevisiae SEY2102/pAGX3, the total activities of the enzymes reached about 7.91 units/ml for endoxylanase and 0.43 units/ml for endoglucanase.
In the fed-batch culture with intermittent feeding of yeast extract and glucose, the total activities of 24.9 units/ml for endoxylanase and 0.84 units/ml for endoglucanase were produced which were about 3.1- fold and 2.0-fold increased levels, respectively, compared to those of the batch culture. Most of endoxylanase and endoglucanase activities were found in the extracellular media. This recombinant yeast could be useful for the development of simultaneous saccharification bioprocess of the cellulose and xylan mixture.

국문 초록 (Abstract)

Endoxylanase와 endoglucanase 유전자가 ADH1 프로모터 하류에 따로따로 삽입된 pAGX3 플라스미드를 함유한Saccharomyces cerevisiae에서 endoxylanase와 endoglucanase 유전자는 성공적으로 발현되었으며, YPD 배지에서의 회분배양 결과, endoxylanase는 7.91 units/ml, endoglucanase 는 0.43 units/ml에 달하는 총활성을 보였다. Yeast extract 와 포도당을 간헐적으로 공급하는 유가배양에서 endoxylanase 와 endoglucanase의 총활성은 24.9 units/ml과 0.84 units/ ml을 각각 보였으며, 이는 회분배양에서 발현된 각각 활성의 3.1배와 2배에 해당되었다. 또한, 대부분의 endoxylanase 와 endoglucanase 활성은 세포밖 배지에서 측정되어, 향후이 재조합 효모는 섬유소(cellulose)와 xylan 혼합물의 동시당화 바이오공정 개발에 활용될 가능성이 높다 하겠다.

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