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Research Summary

Overview

Professor Rha's research is aimed at the discovery and engineering of novel biomolecules in a complex systems biology framework and biomaterials for process manufacturing. The focus is on determination of their structure, function and bioactivity. Transcriptional profiling, genomic sequencing and analysis, LC and GC mass spectroscopy, NMR, molecular imaging and micro-rheology are the primary tools for the analysis of the bioactivities of molecules and living systems at the genomic, molecular and cellular level to identify and engineer bio-systems to produce valuable natural medicinal and industrial products.

Natural Product Discovery

One of the Rha lab's focus areas is in the identification, isolation, characterization and standardization of new bioactive compounds from natural or industrial material.

Polyphenols from Palm Oil Mill Effluent
Palm Oil Mill Effluent (POME) is an aqueous effluent from palm oil mills. Tens of millions of tonnes of this waste stream are produced yearly by the palm oil industry, creating a serious disposal problem. Researchers at the Malaysian Palm Oil Board (MPOB) have discovered that POME contains a high concentration of phytochemicals, particularly polyphenols. It is widely considered that polyphenols may have multiple positive and preventative health effects, including the prevention or attenuation of several chronic degenerative disorders. The Rha lab is isolating, characterizing and standardizing the chemical structure, physical properties and biological activities of phenolic compounds from POME. The MPOB supports this research with extensive collaboration between the Biomaterials Science and Engineering Laboratory, MPOB and additional international institutions.

Eurycoma longifolia (Tongkat Ali)
Eurycoma longifolia (Tongkat Ali) is a small evergreen tree that grows in the tropical regions of South East Asia. It is used in traditional medicine for many purposes, most notably as an aphrodisiac. Studies have verified that it increases testosterone production in humans and animals. In the Rha lab, in cooperation with the Forest Research Institute Malaysia (FRIM), the active component, an androgenic peptide, was isolated and characterized. A patent for this peptide and a procedure for its isolation was granted. Procedures for standardizing and testing herbal Tongkat Ali products for purity and quality are now under development.

Centella asiatica (Pegaga)
Another common herb from South East Asia, Centella Asiatica is used in traditional medicine to treat a wide range of ailments. Research on Centella Asiatica has focused on isolating new compounds and evaluating their for bioactivity, as well as characterizing the biological activity of Medicassic acid and Asiatic acid, two compounds commonly extracted from the roots of the plant.

Oil Palm Biotechnology

Bioplastics from Palm Oil
Polyhydroxyalkanoates (PHA) are a family of naturally occurring polymers that can be produced by micro-organisms. PHAs can be engineered for many applications to replace conventional polymers. Furthermore, PHA are naturally biodegradable, making them a highly attractive alternative to petroleum-based plastics. Current research on biosynthesis in professor Rha's group is focused on engineering strains of bacteria to produce PHA from palm oil feedstock to yield a highly competitive and uniquely environmentally advantageous plastics manufacturing process.

Oil Palm Tissue Culture
Oil Palm is the world's largest source of vegetable oil for food production, biodiesel and an increasing array of natural products. While mature oil palm plants are very productive, both production and research on this important resource are hampered by its slow growth and labor-intensive cultivation. Oil palm tissue culture research in professor Rha's laboratory is focused on advanced cultivation techniques to reliably produce healthy oil palm plantlets with faster growth rates and higher productivity.

Malaysia-MIT Biotechnology Partnership Program (MMBPP)

Some of this research has been carried out under the Malaysia-MIT Biotechnology Partnership Program (MMBPP) a joint program between the Biomaterials Science and Engineering Laboratory at MIT and several Malaysian research institutions supported by the Ministry of Science, Technology and Innovation, Malaysia. Professor Rha directs MMBPP research at MIT, which is primarily carried out at the Biomaterials Science and Engineering Laboratory (also directed by Professor Rha) and the Sinskey Laboratory in the Biology department at MIT.

Selected Publications

Rafat, M., Fong, K.W., Goldsipe, A., Stephenson, B.C., Coradetti, S., Sambandan, T.G., Sinskey, A.J. and Rha, C.K. Association (Micellization) and Partitioning of Aglycon Triterpenoids. J. Colloid and Interface Science. (2008) 325 324-330

Willis, L.B., Gil, A.G., Lee, H.T., Choi, D.S., Schoenheit, J., Ram, R.J., Rha, C.K. and Sinskey, A.J. Application of Spectroscopic Methods for the Automation of Oil Palm Culture. Journal of Palm Oil Research Special Issue on Malaysia-MIT Biotechnology Partnership Programme. (2008) 1 1-13.

Choi, D.S., Andrade, M.H.C., Willis, L.B., Cho, C.W., Schoenheit, J., Boccazzi, P., Sambanthanmurthi, R., Sinskey, A.J., Rha, C.K. Effect of Agitation and Aeration of Yield Optimization of Oil Palm Suspension Culture. Journal of Palm Oil Research Special Issue on Malaysia-MIT Biotechnology Partnership Programme. (2008) 1 23-34.

Kurosawa, K., I. Ghiviriga, T.G. Sambandan, P.A. Lessard, J.E. Barbara, C.K. Rha, and A.J. Sinskey. Rhodostreptomycins, Antibiotics Biosynthesized Following Horizontal Gene Transfer from Streptomyces padanus to Rhodococcus fascians. J. Am. Chem. Soc. (2008) Published online.

Govindan, G., Sambandan, T.G., Govindan, M., Sinskey, A. Vanessendelft, J., Adenan, I. and Rha, C.K. A Bioactive Polyacetylene Compound Isolated from Centella asiatica. Planta Medica (2007) 73 597-599.

Cho C.W., Choi D.S., Cardone M.H., Kim C.W., Sinskey A.J. and Rha C. Glioblastoma cell death induced by asiatic acid. Cell Biology and Toxicology. (2006) 22(6):1573-6822.

Kurosawa K., Bui. V.P., VanEssendelft J. L., Willis L.B., Lessard P.A., Ghiviriga I., Sambandan T.G., Rha C.K., Sinskey A.J. Characterization of Streptomyces MITKK-103, a newly isolated actinomycin X2-producer. Applied Microbiology and Biotechnology . (2006) 72(1):145-54

Lawrence, A.G., J. Choi, C. Rha, J. Stubbe, and A.J. Sinskey. In vitro analysis of the chain termination reaction in the synthesis of poly-(R)-b-hydroxybutyrate by the Class III synthase from Allochromatium vinosum. Biomacromolecules, (2005) 6(4):2113-2119, 2005.

Gorret, N., S.K. bin Rosli, S.F. Oppenheim, L.B. Willis, P.A. Lessard, C. Rha, and A.J. Sinskey. Bioreactor culture of oil palm (Elaeis guineensis) and effects of nitrogen source, inoculum size, and conditioned medium on biomass production. J. Biotechnol. (2004) 108:253-263.

Coldren, C.D., P. Hashim, J.M. Ali, S.K. Oh, A.J. Sinskey & C.K. Rha. Gene expression changes in the human fibroblast induced by Centella asiatica triterpenoids. Planta Med. (2003) 69(8):725-32.

Fry, R.C., T.G. Sambandan & C.K. Rha. DNA damage and stress transcripts in Saccharomyces cerevisiae Mutant sgs1. Mechanisms of Ageing and Development. 124 (2003) 839-846.

Osman, A., Jordan, B., Lessard, P.A., Muhammad, N., Haron, M.R., Riffin, N.M., Sinskey, A.J., Rha, C.K., and D.E. Housman. Genetic diversity of Eurycoma longifolia inferred from single nucleotide polymorphisms. Plant Physiology, (2003) 131(3):1294-1301.