Faculty

TAN Teck Koon

Associate Professor

Contact Information:

Department of Biological Science
National University of Singapore
14 Science Drive 4
Singapore 117543



dbstantk@nus.edu.sg

Academic Qualifications

PhD (Botany), 1980, University of Singapore

Research Interests

Fungi impact on human life in many areas such as health and wellness, agriculture, horticul-ture, biotechnology, and food production. Knowledge in fungal biodiversity, fungal biology and fungal ecology constitutes the fundamentals towards understanding, exploiting and managing fungi in these different areas. The Mycology and Fungal-Plant Interactions Laboratory focuses on the twin approach of studying the biodiversity of local/tropical fungi, and the exploitation of se-lected fungi. Under biodiversity studies, the present key interests are in the aquatic and marine fungi of which about 200 local species have been recorded, and endophytic symbiotic fungi of agricultural/horticultural relevance. Applied mycological interests focus on fungal enzymes, fun-gal symbiosis in orchids, fungal chitosan, and fungal airspora in relation to allergenic responses.

Current Projects

Biodiversity and ecology of aquatic/marine fungi.

This is an on-going pursuit to document the local tropical mycoflora, and to isolate strains of fungi for preservation in the Fungal Culture Collection, from which specimens are drawn for teaching and research. The coastal marine and mangrove fungi around Singapore have been documented. Currently, the fungi associated with marine soft corals are being studied and asso-ciated with this is the investigation on anti-fungal extracts of these corals.

Fungal-Plant Interactions

The main interest is on the Rhizoctonia - Orchid symbiosis. Aspects studied include the opti-mization for growth and development of orchid seedlings and tissue cultures through fungal sym-biosis, production of 'mycorrhizal-seeds', and the characterization of symbiotic and pathogenic Rhizoctonia strains. We have shown that mycorrhizal orchid seeds give a higher percentage germination and better growth and development of seedlings, as compared to aseptic germina-tion on synthetic media. Another interaction being studied is that of the Pisolithus-Acacia mangium symbiosis.

Fungal allergens

The fungal airspora profile in various local neighbourhoods has been mapped and based on this, highly allergenic spores of local fungal species have been identified. These are different from typical allergenic species reported in literature. Current work focuses on spore imaging and the characterization of allergenic spore proteins.

Fungal chitosan

Chitosan is a polymer of pharmaceutical, medical and industrial relevance. Chitosan produc-tion from fungi has certain advantages over the only current mode of commercial production i.e. from crustacean shells. Our current work is on the elucidation of the chitin deacetylase gene involved in the production of chitosan in Gongronella butleri. This is a continuation of work done to screen fungi with good chitosan yields, optimization of chitosan production in batch cultures, characterization of fungal chitosan, and mutation to obtain high yielding fungal strains.

Selected Publications

  1. Wang, Y, T K Tan, G K Tan, J D Connolly & L J Harrison. Microbial transformation of the sesquiterpenoid (-)-maalioxide by Mucor plumbeus. Phytochemistry, 67 (2006): 58- 61.
  2. Jayakumar, P & T K Tan. Phosphorus solubilization by ectomycorrhizal Pisolithus tinctorius in pure culture and in association with Acacia mangium. Symbiosis, 39 (2006): 125-139.
  3. Jayakumar, P & T K Tan. Changes during early ectomycorrhizal formation by Pisolithus tinctorius on Acacia mangium and their impact on nodule formation by Bradyrhizobium sp. Symbiosis, 40 (2005): 141-149.
  4. Jayakumar, P & T K Tan. Growth performance and nodulation response of Acacia mangium co-inoculated with Bradyrhizobium sp. and Pisolithus tinctorius. Symbiosis, 40 (2005): 109-114.
  5. Ma, M, T K Tan & S M Wong. Identification and molecular phylogeny of Epulorhiza isolates from tropical orchids. Mycological Research, 107 (2003): 1041-1049.
  6. Nwe, N, S Chandrakrachang, W Stevens, T Maw, T K Tan, E Khor & S M Wong. Production of fungal chitosan by solid state and submerged fermentation. Carbohydrate Polymers, 49 (2002): 235-237.
  7. Maw, T, T K Tan, E Khor & S M Wong. Selection of Gongronella butleri strains for enhanced chitosan yield with UV mutagenesis. Journal of Biotechnology, 95 (2002): 189-193.
  8. Maw, T, T K Tan, E Khor & S M Wong. Complete cDNA sequence of chitin deacetylase from Gongronella butleri and its phylogenetic analysis revealed clusters corresponding to taxonomic classification of fungi. Journal of Bioscience and Bioengineering, 93 (2002): 376-381.
  9. Tan T K. Shrinking mangroves, Thriving fungi. In: Fungi in Marine Environments, ed. K D Hyde, 235-246. Fungal Diversity Press, 2002.
  10. Chew, F T, S H Lim, H S Shang, M D Siti Dahlia, D Y T Goh, B W Lee, H T W Tan and T K Tan. Evaluation of the allergenicity of tropical pollen and airborne spores in Singapore. Allergy, 55 (2000): 340-347