The Helm Lab
Fralin Biotechnology Center,
Department of Wood Science and Forest Products, Virginia Tech,
Blacksburg, VA 24061-0346
Research Interests. The laboratory of wood
and carbohydrate chemistry in the Fralin Biotechnology Center
at Virginia Tech has wide-ranging research interests:
- Heartwood Formation in Hardwoods. The Eastern United
States has the largest reserve of Oak timber in the world, and
the
value
of oak timber produced yearly is over three billion dollars.
The extractives present in the oaks contribute to the high durability
of the wood as well as to the flavors associated with spirits
aged in oak casks. The major extractives found in oak wood are
ellagitannins, a complex set of molecules with wide ranging chemical
and biochemical properties. We are interested in both the chemistry
and biochemistry of these and related molecules, with emphasis
on their potential pharmaceutical applications.
- Plant Cell Wall Structure. Despite years of intense
research, the chemical and biochemical aspects of plant cell
wall structure and development remain obscure. We are interested
in the relationship between the structural components of the
woody cell wall and the role polysaccharides and lignin play
in generating the biopolymer matrix. Current investigations center
on the covalent relationship between lignin and polysaccharides,
as well as the role tannins play in woody cell wall maturation.
- Carbohydrate Chemistry and Biochemistry. Carbohydrates
are ubiquitous in nature and their properties and uses are too
numerous to mention. Projects in this area include improving
the fermentation efficiency of xylose to ethanol for use as liquid
fuels, and the structural elucidation of polysaccharides. In
particular, we are interested in the extracellular polysaccharides
produced by extremophiles, organisms that grow under conditions
of severe light, heat, cold and/or desiccation.
A
desiccated cyanobacteria culture showing the cells (white dots)
embedded in a protective glycan. The glycan (or extracellular
polysaccharide, EPS) protects the cell from stress brought about
by the lack of water and/or the presence of heat. Such organisms
are "extremophiles" and we are interested in the chemical
and biochemical properties of the EPS, as well as the molecular
biology behind its biosynthesis. Cyanobacteria can photosynthesize
as well as fix nitrogen, thus they are very capable at surviving
at locations such as deserts, Antarctica and asphalt shingle roofs.
A better understanding of the processes used by extremophiles
to protect themselves from the environment may lead to new and
better ways to stabilize pharmaceutical and/or food products.
This is a joint effort between the Helm Lab and the Laboratory
of Dr. Malcolm Potts, Department of Biochemistry.
Research Projects
Wood Chemistry and Biochemistry
- Jody Jervis, Laboratory
Manager
- Lei Zhentian, Graduate Student
- Heidi Leeson, Laboratory Technician
Classes Taught by Dr. Helm Available on the
Web