학과세미나 (고려대, 한성옥교수)
생명과학과
2012-04-16
세미나 장소 : J219
세미나 일시 : 2012.04.24. (17:00)
세미나 발표자 : 고려대, 한성옥교수.
세미나 일시 : 2012.04.24. (17:00)
세미나 발표자 : 고려대, 한성옥교수.
Designer Microbes for Biofuel Production from Biomass
The term biomass refers to all organic matter generated through photosynthesis and other biological processes. It includes both terrestrial as well as aquatic matter. High moisture plants and marine biomass are most suitable for biological digestion. Nature has provided non-complexed or complexed enzyme hydrolysis systems. Compared to the non-complexed enzyme systems, the complexed enzyme system exhibits much greater degradative potential. Therefore, the development of a complexed enzyme system could improve the hydrolysis of biomass materials. In this study, we expressed miniCbpA, a recombinant scaffolding protein from Clostridium cellulovorans to assemble the enzyme complex via cohesin-dockerin interaction. We constructed a chimeric endoglucanase cCelE from Clostridium thermocellum and a chimeric agarase cAgaB from Zobellia galactanivorans containing the catalytic domain fused with a dockerin domain from C. cellulovorans EngB for hydrolysis of cellulosic and marine biomass, respectively. The assembly of minicellulosomes by Corynebacterium glutamicum and agarolytic complexes by Escherichia coli increased the activity against pre-treated cellulose by approximately 3-fold and the agar substrate by approximately 2-fold, respectively, compared with that for the corresponding enzymes alone. Moreover, the metabolically engineered host strains such as Saccharomyces cerevisiae expressing minicellulosome was able to ferment amorphous cellulose into biofuel such as ethanol and biodiesel with the aid of β-glucosidase 1 produced from Saccharomycopsis fibuligera. The development of enzyme complex with synergic activity in metabolically engineered industrial microbes may potentially lead to the commercial production of useful products from biomass materials at low costs.