Fungal physiology 
This group is a collaboration between
the CBS Fungal Biodiversity Centre and Utrecht University, Chair of
Microbiology. Information on research of this group at the CBS Fungal
Biodiversity Centre can be found here.
Fungal physiology is the basis of biotope and global dispersion
of fungal species. It determines the nutrients it can use, the environmental
conditions it can endure and its competitive position in its ecosystem.
The ability of fungi to survive in every known biotope, both natural
and man-made, relies in part on their capacity to use a wide range of carbon
sources. In nature, many fungi degrade polymeric carbon sources (e.g.
polysaccharides, proteins, lignin) to use the monomeric components as carbon
source. However, the available carbon sources vary strongly in nature, both
between biotopes and in time. While some fungi have become specialists that
focus on specific carbon sources or specific biotopes, other have are more
generalists that can grow in many biotopes and use a large variety of carbon
sources. Differences in physiology may therefore also reflect species
boundaries.
Degradation of polymeric carbon sources occurs extracellularly by
a broad range of enzymes, of which the production is tightly controlled by a
network of regulators. This enables fungi to produce an enzyme mixture that is
tailored specifically for the available carbon sources at any given time. The
released monomeric compounds are transported into the cell and metabolized
through a large variety of metabolic pathways. These pathways are often
co-regulated with the extracellular enzymes that release the compounds
entering the pathways, resulting in a highly complex regulatory and metabolic
network. To study fungal
physiology in relation to natural substrates it is therefore necessary to
address all these aspects of fungal biology: production of extracellular
enzymes, metabolic pathways and regulators controlling the fungal response to
the substrates present in the environment.
How fungi choose from Nature’s menu: Unravelling the molecular
basis of substrate utilisation by Aspergillus
niger (Evy Battaglia, Alexandra Vivas Duarte, Ronald de Vries)
In this STW-VIDI project we aim to understand the substrate preferences from A.
niger during growth in a natural environment. The topic will be addressed
by micro-array analysis to compare the transcriptional response during growth
on natural and pure substrates, and by studying the temporal and spatial
expression in the mycelium. Moreover, identification of the responsible
transcriptional regulators and studying the interaction between them will
result in a better understanding of the regulatory network involved in carbon
consumption of this fungus.
Modification of the expression of transcriptional regulators of
Aspergillus to improve industrial fermentations and use of agricultural
by-products (Birgit Gruben, Isabelle Benoit, Ronald de Vries)
In this STW project we aim identify transcriptional regulators of Aspergillus
niger that are involved in pectin and galacto(gluco)mannan utilisation.
These polymers are of interest because of their abundance in crude carbon
sources. Modification of the regulatory system should result in strains that
grow faster, extract more energy from their crude carbon source and that
produce higher amounts of industrial proteins and metabolites. In addition,
the research should result in the production of high value products from
agricultural by-products.
This
project is a collaboration with Leiden University.
Novel high performance enzymes and micro-organisms for conversion
of lignocellulosic biomass to bioethanol (NEMO) (Oliver Blechert, Ronald de
Vries)
In this EU project with 20 partners (including UU and CBS) we aim to develop
new innovative solutions for the two major challenges in 2nd
generation bioethanol production: it will identify and develop novel enzymes
for efficient biomass hydrolysis, and robust micro-organisms for efficient
fermentation of C6 and C5 biomass sugars. The tasks within our group focus
mainly on identification of novel enzymes.
Dissecting sequential substrate utilization in Aspergillus
niger using transcriptomics and proteomics (Alexandra Vivas Duarte, Ronald
de Vries)
In this NGI/Kluyver Horizon Breakthrough project we aim to determine whether
polysaccharide-specific transcriptional activators mediate sequential
utilization of polysaccharides by Aspergillus
niger using an approach
that combines transcriptomics, proteomics and sugar analysis.
