Genomics Research Center, Academia Sinica, Taiwan
Associate Research Fellow, Department of Medical Research, China Medical University Hospital, Taiwan (2013) Postdoctoral Fellow, Genomics Research Center, Academia Sinica, Taipei, Taiwan (2008-2013) Visiting scholar, Dept of Ecology & Evolution, the University of Chicago, USA (2012) Visiting scholar, Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan (2009) Postdoctoral Fellow, Biotechnology Center, National Chung Hsing University, Taiwan (2006-2007) Ph.D., Dept. of Life Sciences, National Chung Hsing University, Taiwan (2001-2006) B.S., Dept. of Nutrition, Chung Shan Medical University, Taiwan (1997-2001)
To achieve economical biofuel production, such as cellulosic ethanol, a host that can do both cellulosic saccharification and ethanol fermentation is desirable. However, to engineer a non-cellulolytic microbe to be such a host requires synthetic biology techniques to pursue large-scale genomic engineering of the host. We have developed an efficient high-throughput method that can simultaneously introduce many genes into a genome. It is called Promoter-based Gene Assembly and Simultaneous Overexpression (PGASO). PGASO was applied to transform multiple cellulase genes into the genome of Kluyveromyces maxianus KY3 with a single selection marker gene. Six genes of different GH families were cloned from the cellulolytic fungi Trichoderma, Aspergillus, and Neocallimastix. The recombinant strain is capable of co-expressing a cellulase cocktail and can directly convert microcrystalline cellulose to ethanol. Our study shows that a designer yeast can be developed to simultaneously express different GH genes, and our enzyme cocktail shows a synergistic effect of these enzymes in digesting cellulose. Thus, PGASO can serve as a platform to study enzyme synergism in a single host and can be used to construct a host for a cell factory for enzyme production. In addition, KY3 can be co-cultured with bacterial hosts. A designer Bacillus subtilis that carries eight cellulosomal genes of Clostridium thermocellum, including one scaffolding protein gene, one cell-surface anchor gene, and six cellulase genes, was constructed and employed as a partner of KY3 for cellulosic bioethanol production. A novel dual-microbe co-culture system is developed to improve bioethanol production.