[bioinfo] CS 591 BIO: Talk on Friday (March 30) by Dr. Lewis Liu from USDA

[Saurabh Sinha]

Hello,
    Our speaker this Friday is Dr. Z. Lewis Liu from USDA, who will  
be talking about "Functional genomics on inhibitor stress tolerance  
of ethanologenic yeast Saccharomyces cerevisiae". Dr. Liu's work has  
great relevance to improved biofuel production, one of the big  
challenges of today. Details of his talk are given below.

    DATE: Friday, March 30
    TIME: 10:30 - 11:30 am.
    PLACE: 3401 Siebel Center.

    Thanks,
    Saurabh
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Towards functional genomics on inhibitor stress tolerance of  
ethanologenic yeast Saccharomyces cerevisiae

Z. Lewis Liu
U.S. Department of Agriculture, ARS, National Center for Agricultural  
Utilization Research

One major barrier of cost-efficient biomass conversion to ethanol is  
inhibitory compounds generated during biomass pretreatment using  
economic dilute acid hydrolysis.  At USDA, we study mechanisms of  
inhibitor stress tolerance and develop tolerant ethanologenic yeast  
Saccharomyces cerevisiae using functional genomics.  Over 500 genes  
were identified to be significantly differentially expressed in  
response to representative inhibitors furfural or 5- 
hydroxymethylfurfural (HMF).  A set of universal external RNA  
controls was developed that can be applied to different platforms of  
microarray and real time qRT-PCR, including SYBR Green and TaqMan- 
probe based chemistry.  The development of the universal RNA controls  
made it possible to use qRT-PCR as a high throughput platform for  
absolute mRNA quantification assays.  During the course of the study,  
we identified HMF metabolic conversion product as furan methanol (2,5- 
bis-hydroxymethylfuram), and synthesized the compound that allowed us  
to study fermentation metabolic profiles in the presence of the  
inhibitors.  Such studies further led us to illustrate that multiple  
gene-mediated aldehyde reduction is a mechanism of the in situ  
detoxification of furfural and HMF.  Using a directed evolutionary  
adaptation method, we developed tolerant ethanologenic yeast strains  
that can detoxify single inhibitors or inhibitor complex and produce  
a normal yield of ethanol.  Currently, these strains are used for  
studies to dissect genomic mechanisms of the detoxification and the  
tolerance.

About the speaker:
Dr. Zonglin Lewis Liu obtained his B.S. studying Plant Protection  
from Jilin Agricultural University, China (1977), and his Ph.D. was  
on Plant Pathology, at the University of Illinois (1990). He was a  
Postdoctoral Research Associate in Molecular Biology at the U of I,  
from 1990-1992, and held the positions of Visiting Assistant  
Professor, Research Assistant Professor, and Research Associate  
Professor at the U of I from 1994-2002. Since 2002, Dr. Liu has been  
a Research Molecular Biologist at USDA-ARS-NCAUR. He leads genomic  
studies of microbial stress tolerance for low cost biofuels and  
bioproducts.