[2014 Fall Life Sciences & IBB Regular Seminar]
   
     
  ▶Subject: Regulation of Triacylglycerol Biosynthesis in Microalgae
  
  ▶Speaker: Prof. Christoph Benning (Department of Biochemistry and Molecular Biology, Michigan State University)
          
  ▶Date: 4:00PM/Oct./10(Fri)/2014
         
  ▶Place: Auditorium(1F), Postech Biotech Center
         
          *Abctract
        Triacylglycerols sequestered in lipid droplets provide safe storage for fatty acyl groups when cells experience adverse conditions, e.g. nutrient deprivation. The ability of microalgae to synthesize and store large quantities of triacylglycerols has become a prominent engineering target, because increasing the triacylglycerol content of microalgae will enhance the energy density and the quality of the biomass as feedstock for feed, food, and fuels. A key problem hampering maximization of triacylglycerol production in the algal biomass is the inverse relationship between cell growth and division on one hand, and triacylglycerol accumulation on the other. Nitrogen deprivation induces a quiescent state in Chlamydomonas, when cell divisions temporarily come to a halt and triacylglycerol biosynthesis is induced. Upon refeeding nitrogen, the cells exit quiescence, resume growth and remobilize triacylglycerol. Thus, lipid metabolism is intricately interwoven with other cellular processes making its engineering a daunting task. As a first step, we are striving to gain a thorough mechanistic understanding of triacylglycerol biosynthesis, i.e. the enzymes involved, its integration into overall cellular metabolism, and its regulation during the cell cycle. Towards this end we are applying genomic and genetic approaches in reference microalgae, primarily Chlamydomonas, but more recently also Nannochloropsis. Mutants of Chlamydomonas with deficiencies in enzymes and regulatory factors required for triacylglycerol biosynthesis have already provided important new insights into specific aspects of microalgal lipid metabolism including the role of enzymes involved in lipid turnover, a lipid transporter, and a transcription factor orchestrating the adjustment of transcriptional networks during entry and exit of quiescence.

  ▶Inquiry: Prof. Lee, Youngsook (279-2296)
        
    * This seminar will be given in English