Projects / Programmes
Glycerol channel involved in osmoadaptation in halophilic fungus Hortaea werneckii
| Code |
Science |
Field |
Subfield |
| 4.06.00 |
Biotechnical sciences |
Biotechnology |
|
| Code |
Science |
Field |
| T490 |
Technological sciences |
Biotechnology |
halophilic fungi, aquaglyceroporin, characterization, functional complementation, osmoadaptation, glycerol transport
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
20395 |
PhD Tina Kogej |
Biochemistry and molecular biology |
Head |
2008 - 2010 |
63 |
Organisations (1)
Abstract
Halophilic black yeast Hortaea werneckii is a dominant eukaryotic microorganism in hypersaline water of solar salterns. It was first isolated from the Sečovlje salterns in Slovenia. Later it was confirmed as inhabitant of extremely saline waters by isolation from various salterns worldwide. H. werneckii adapts to high osmotic pressure by accumulation of osmolytes, primarily glycerol. It is capable to survive hypo-osmotic shocks by quick release of glycerol, possibly through a transmembrane channel orthologous to aquaglyceroporin Fps1p in Saccharomyces cerevisiae. In this project I propose to identify and characterize a glycerol channel in the halophilic fungus H. werneckii responsible for quick release of glycerol during adaptation to hypo-osmotic shock. I will use a PCR approach with primers designed based on conserved signature protein sequences of fungal Fps1p orthologues. Thus, I will amplify a part of the gene for glycerol channel that will be used as a probe to screen a genomic library of H. werneckii for the whole gene sequence. Missing parts of the gene sequence will be amplified by primer walking and rapid cloning of cDNA ends. The sequence will be characterized and compared to other glycerol channels by molecular modeling. I will analyze the glycerol channel functionally by heterologous complementation of S. cerevisiae mutants with a defect in the glycerol channel Fps1p. Fps1p mutants do not survive hypo-osmotic shock in contrast to wild-type cells. By functional complementation, transformed cells are expected to have a phenotype similar to those of the wild type cells. Identification and characterization of the glycerol channel from a halophilic yeast will add important knowledge of structure and function of glycerol channels involved in osmoadaptation and could have a possible industrial importance.
Significance for science
A better understanding of glycerol movements across cell membranes as well as its metabolism can help to unravel many cell homeostasis mechanisms. Additionally, it can contribute to the improvement of biotechnological processes, as glycerol properties make it useful in numerous industrial, therapeutic and diagnostic applications. Glycerol is currently produced in large amounts as a by-product during fat splitting and biodiesel fuel production. The use of biodiesel is expected to grow in the future due to the environmental policy of the EU. The increase in the production of biodiesel has resulted in a glut of glycerol that has led to a precipitous market price drop. At present, glycerol is in surplus but in the near future it could become a waste problem. Over the past decade, both chemical and biotechnological processes to convert glycerol to value-added chemicals have been increasingly explored.
Membrane transport constitutes one of the most fundamental processes in all living cells with proteins as major players. Proteins as channels provide highly selective diffusive pathways gated by environmental factors, and as transporters furnish directed, energetically uphill transport consuming energy. The characterization and identification of glycerol transporters is important for several reasons: (i) it helps in our understanding of osmoadaptation in a halophilic yeast, new model organisms for studies of osmoadaptation, and thus represents a general advancement of knowledge, (ii) it might enable better use of surplus glycerol resulting from biodiesel production by cloning the gene coding for glycerol transporter in industrially important microorganisms that could be used in converting glycerol to value-added chemicals.
Significance for the country
Halophilic fungi have been known only since 1997. Hypersaline water in the active part of Sečovlje saltern is the only natural ecological niche of the halophilic black yeast H. werneckii and of some other halotolerant and halophilic fungal species in Slovenia. Even though halophilic fungi were originally discovered in Slovenia, they have been later recognized as an integral part of microbial communities in the salterns worldwide. Research on the halophilic microorganisms from this unique environment is important for salt producers in Sečovlje saltern, as this is a nature park and one of Slovenia's most valuable natural and cultural heritage sites. Research on the microorganisms from this unique environment might therefore indirectly affect the protection of this environment and of its biodiversity.
The research of halophilic eukaryotic microorganisms provides new basic knowledge on life. Studies of osmoadaptation mechanisms on microorganisms, which were isolated from our environment, are therefore of special importance for Slovenia. The research on halophilic fungi in Sečovlje saltern and its entire microbial community have started over a decade ago in the group of Prof. Dr. Nina Gunde-Cimerman at University of Ljubljana, Biotechnical faculty, which is the leading research group in the field of halophilic fungi.
The importance of the studies of eukaryotic halophiles is demonstrated by numerous scientific publications of the research group of Prof. Dr. Nina Gunde-Cimerman with leading scientists in this research area. The research group from Slovenia has published 4 research articles in the thematic issue on black yeasts in December 2008 in the highest ranking journal in the area of mycology, Studies in Mycology, of which 2 were on H. werneckii. In May 2010, our research group also organized an international scientific conference for the working group on black yeasts, an important meeting for Slovenian science. The results of this research project were presented at international conferences, The results will be also published in a scientific journal.
Most important scientific results
Annual report
2008,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2008,
2009,
final report,
complete report on dLib.si
