Download Excellence PhD student project proposals 2011 Plant cell wall

Excellence PhD student project proposals 2011
Plant cell wall biochemistry, molecular biology and metabolic engineering
Description: The main constituents of plant cell walls are cellulose and noncellulosic polysaccharides, e.g.
pectins, hemicelluloses. Together with lignins and structural proteins these carbohydrates form a complex
network reinforced by multiple cross-links. The network accommodates a variety of mechanical
requirements during plant life and its physical and mechanical properties are comparable to those of the
best synthetic materials. These properties are exploited in various products such as paper, textiles, building
materials, etc. But in addition to these traditional sectors, there is a great potential to develop carbohydratebased materials that combine environmental friendliness and biocompatibility with high performance and
increased functionality, through the metabolic engineering of plant cell walls. Plant cell walls are an
abundant source of carbohydrates that can be used to produce biofuels through saccharification processes,
but these must be improved to overcome the recalcitrance of plant cell walls to digestibility. Manipulating
the composition and architecture of plant cell walls for material development and improved production of
biofuels has been poorly exploited so far, but this is emerging as a priority area owing to the necessity to
find alternatives to our unsustainable use of fossil fuels to supply energy, chemicals and materials.
The main goal of this project is to modify the natural composition of plant cell walls by engineering
carbohydrate biosynthetic pathways for a wide range of applications. The research program comprises the characterization of key genes involved in plant cell wall metabolism particularly biosynthesis - including expression in planta and in heterologous systems (yeast, bacterial
systems), purification and biochemical characterization of recombinant enzymes. The work also involves
the metabolic engineering of plant cell walls and microbial systems as well as analyses of plant cell walls
and polysaccharides synthesized in vitro.
The research involves interaction with ongoing national and international collaborators from both
Academia and industry, in the context of national and EU-funded programs.
Major techniques involved in the PhD project: metabolic engineering of plants, gene technology,
protein biochemistry, plant and microbial molecular and cell biology, functional characterization of genes
using in vivo and in vitro approaches.
Primary site of location: Division of Glycoscience, AlbaNova main building, floor 2.
Contact: Professor Vincent Bulone, Division of Glycoscience
E-mail: [email protected]
Tel: 08 5537 8841
Website: http://www.biotech.kth.se/glycoscience/Vincent_Bulone
Production
of chitin in planta by metabolic engineering (patented). The left panel shows a FE-SEM picture
of the smooth surface of a plant leaf not expressing the selected chitin synthase gene (control). The middle panel
is an identical tissue as in the left panel but from a plant in which the chitin synthase pathway has been
introduced (plants do not naturally produce chitin). Note the cracks and rougher structure compared to the
control presented in the left panel. The panel on the right is an enlargement of one area of the middle panel
showing the production of nanostructures of chitin with a rather homogeneous size. This type of material has
potential application in the textile industry (design of functional textiles).