Monday, August 11, 2008 - 1:00 PM
S43

Genome-level enquiry into adaptive evolution

Goutham Vemuri, Department of Systems Biology, Chalmers University of Technology, Kemivagen 10, Goteborg, 412 96, Sweden, Chris Workman, Center for Biological Sequence Analysis, Denmark Technical University, Bldg 208, Lyngby, 2800, Denmark, and Jens Nielsen, Chemical and Biological Engineering, Chalmers University of Technology, Quantitative Systems Biology, Kemivägen 10, Göteborg, 41296, Sweden.

The field of metabolic engineering has evolved from overexpressing a gene that encodes for an enzyme that mediates the rate-limiting step or deleting those contribute to by-product formation to targeting regulatory networks. Mapping signaling cascades and identifying targets of transcriptional regulators is now easier ever before, and yet, it is still a challenge to engineer complex traits into metabolic networks. For such applications, alternate approaches such as adaptive evolution have proved highly successful. We employed the natural evolution process in the lab to enhance growth of bakers yeast on galactose. Galactose is chemically identical and structurally very similar to glucose, the preferred carbon and energy source. Yeast grows three times slower on galactose than on glucose although the galactose consumption pathway has only two additional reactions before entering the mainstream glycolytic pathway. Yeast strains that have been evolved for about 500 generations show increased galactose uptake without any increase in the aerobic fermentation. We used high resolution tiling arrays to identify any chromosomal changes along with complementary expression profiling. The impact of these genomic changes, caused by the evolution process on the phenotype will be discussed in the context of increased growth rate on galactose.

See more of Genomic Advances in Industrial Microbiology
See more of Invited Oral Papers

See more of The Annual Meeting and Exhibition 2008 (August 10 - 14, 2008)