Isolation of fungi from Sabah that produce Bioactive compounds which effect signal transduction
Filamentous micro-fungal strains were isolated from various environments in Sabah especially from the soil of the rain forest.' Sabah with its unique natural resources provides the means for the discovery of new micro-fungal strains with the potential to produce novel bioactive secondary met...
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| Format: | Research Report |
| Language: | English English |
| Published: |
Universiti Malaysia Sabah
2003
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| Subjects: | |
| Online Access: | https://eprints.ums.edu.my/id/eprint/23072/1/Isolation%20of%20fungi%20from%20Sabah%20that%20produce%20Bioactive%20compounds%20which%20effect%20signal%20transduction.pdf https://eprints.ums.edu.my/id/eprint/23072/7/Isolation%20of%20fungi%20from%20Sabah%20that%20produce%20Bioactive%20compounds%20which%20effect%20signal%20transduction.pdf |
| Summary: | Filamentous micro-fungal strains were isolated from various environments in
Sabah especially from the soil of the rain forest.' Sabah with its unique natural
resources provides the means for the discovery of new micro-fungal strains with the
potential to produce novel bioactive secondary metabolite compounds which affect
signal transduction. This is the main focus of this research. A total of 364 fungal
strains were isolated. Extracts from the aerobic liquid fermentation of these fungal
strains were screened for inhibitory effect on Signal transduction of both yeast and
bacterial strains. In the course of this research, soil samples have been collected in
the expeditions that were carried out by this university to remote locations of Sabah.
These expeditions include the primary forest of the Imbak Valley, limestone hill forest
of Tabin Wildlife Reserve, the the lower montane heath forest forest of Maliau Basin
Conservation Area and the montane forest of Mount Trus Madi. The soil samples
were mostly collected from leaf litter under trees and other plants that were identified
to species or genus level. A number for fungal strains were also isolated from
explants and from fungal airborne spores of plates and in around the laboratory. The
characteristics of the micro-fungi strains on the PDA agar were observed and this
includes colour of the aerial and substrate mycelia, difussed pigmentation and growth
rate on the' PDA plates. Microscopic identification was done on the strains which
showed activity on screening tests performed. All the micro-fungal strains isolated
were grown in aerobic condition in liquid fermentation. It was these extracts that were
used for,the screening for specific molecular targets involve in signal transduction,
such as, serinelthreonine phosphatase, MAPK Kinase, MAP Kinase phosphatase,
Ras/Raf protein interaction, and serinelthreonine,kinase. All the screening systems
mention are base on the eukaryotic signalling pathways of yeast except for the
serinelthreonine kinase screen which is base on the prokaryotic signalling pathway of
Streptomyces griseus which shares high similarity with eukaryotic signalling pathway.
In this research, there were fungal strains which showed inhibitory effect to the
serinelthreonine phosphatase type 1 homolog, Glc7p especially the strains H9318
and H9307 from Maliau Basin. These two strains were latter found to inhibit
dephosphorylation of phosphorylase catalyse by the mammalian serineltheronine
phosphatase, Protein Phosphatase type 1 gam a (PP1y) as well. The effect on PP1y
as well as Glc7p is not supprising as both these protein shares more than 75%
homology in its catalytic domain. Three strains which showed positive activity in the
MAPK Kinase screening system are H9013, H9014 and H9019. No fungal strains
were found to be affecting the MAP Kinase Phosphatase (MSG 5) and the RaslRaf
protein interaction which would indicate a positive result. There were numerous
extracts from fungal strains which inhibit the growth of Streptomyces griseus and two
strains which showed potential to be inhibitors of serinelthreonine kinase (AfsK) of
Streptomyces griseus. These two strains were H9016 and H9123. There were also
two fungal strains H9341 and H9346 which showed toxicity in all the screens
performed except for the serineltheronine kinase test of S.griseus. This would
indicate these strains are toxic to at least Scharomycetes cerevisiae cells. The fungal
strains isolated .from soil and from other environment showed some specificity in the
types of strains isolated and the secondary metabolites produced. The microfungi
from Sabah proved to be prolific producers of diverse secondary metabolites which
effect signal transduction and growth of cell. |
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