dr cha

research program application marine CONTACT

E-mail  : cha_ts@umt.edu.my

Tel       : +609-6683394

Fax      : +609-6683105

 research area dr cha PUBLICATION

Ma, N.L., Teh, K.Y., Lam, S.S., Anne-Marie, K. & Cha, T.S. 2015. Optimization of cell disruption methods for efficient recovery of bioactive metabolites via NMR of three freshwater microalgae (Chlorophyta). Bioresource Technology DOI: http://dx.doi.org/10.1016/j.biortech. 2015.03.036.


Jusoh, M., Loh, S.H., Chuah, T.S., Aziz, A. & Cha, T.S. 2015. Indole-3-acetic acid (IAA) induced changes in oil content, fatty acid profiles and expression of four fatty acid biosynthetic genes in Chlorella vulgaris at early stationary growth phase. Phytochemistry 111: 65-71.


Jusoh, M., Loh, S.H., Chuah, T.S., Aziz, A. & Cha, T.S. 2015. Elucidating the role of jasmonic acid in oil accumulation, fatty acid composition and gene expression in Chlorella vulgaris (Trebouxiophyceae) during early stationary growth phase. Algal Research 9: 14-20.


Cha, T.S., Najihah, M.G., Sahid, I.B. & Chuah, T.S. 2014. Molecular basis for resistance to ACCase-inhibiting fluazifop in Eleusine indica from Malaysia. Pesticide Biochemistry and Physiology 111: 7-13.


Cha, T.S., Anne-Marie, K. & Chuah, T.S. 2014. Identification and characterization of RAPD-SCAR markers linked to glyphosate-susceptible and –resistant biotypes of Eleusine indica (L.) Gaertn. Molecular Biology Reports 41: 823-831.


Cha, T.S., Yee, W. & Aziz, A. 2012. Assessment of factors affecting Agrobacterium-mediated genetic transformation of the unicellular green alga, Chlorella vulgaris. World Journal of Microbiology and Biotechnology 28: 1771-1779.


Cha, T.S., Ng, F.L., Aziz, A. & Loh, S.H. 2012. Effect of nitrate on oil content and fatty acid composition of Nannochloropsis sp. at early stationary growth phase. Journal of Sustainability Science and Management 7: 30-36.


Yee, W., Cha, T.S., & Aziz, A. 2012. Factors affecting Agrobacterium-mediated genetic transformation of marine microalga, Nannochloropsis sp. Journal of Sustainability Science and Management 7: 153-163.


Cha, T.S., Chen, J.W., Goh, E.G., Aziz, A. & Loh, S.H. 2011. Differential regulation of fatty acid biosynthesis in two Chlorella species in response to nitrate treatments and the potential of binary blending microalgae oils for biodiesel application. Bioresource Technology 102: 10633-10640.


Cha, T.S., Chen, C.F., Yee, W., Aziz, A. & Loh, S.H. 2011. Cinnamic acid, coumarin and vanillin: alternative phenolic compounds for efficient Agrobacterium-mediated transformation of the unicellular green alga, Nannochloropsis sp. Journal of Microbiological Methods 84: 430-434.


Chuah, T.S., Low, V.L., Cha, T.S. & Ismail, S. 2010. Initial report of glufosinate and paraquat multiple resistance that evolved in a biotype of goosegrass (Eleusine indica) in Malaysia. Weed Biology and Management 9: 179-184.


Microalgae are important constituents of many ecosystems that have remained relatively unexplored and unexploited, despite their great potential as a source for valuable natural products. These photosynthetic microorganism are able to produce high amount of oil with fatty acid composition similar or far better to those of conventional oil producing crops. This characteristic has attracted great research attentions from scientists in various fields with the ultimately aim to develop microalgae as feedstock for edible (high PUFAs) and non-edible (Biofuels) oil industrial applications.

The biosynthesis and accumulation of large amount of oil, accompanied by considerable alterations in fatty acid composition occurs in the microalgae cells can be achieved, when they are placed under stress conditions. Nutrient (such as nitrate and phosphate) starvation, salinity and light intensity stress are among major factors that influence the accumulation of oil in microalgae. These factors have been extensively studies in many species of microalgae, but the exact mechanism as to how these stimuli regulate the fatty acid biosynthesis pathway at the gene level still remains unclear.

Under this research programme, a collection of microalgae from marine and mangrove sources in Malaysia is established at IMB. The microalgae isolates are identified using morphological characteristics, SEM and molecular (18S rDNA) approaches. Several potential species are used as model system in our research. The key genes involve in the fatty acid biosynthesis pathway, such as gene for β-ketoacyl-ACP systhase I, D-9ACP desaturase, w-3 desaturase and w-6 desaturase, as well as their gene promoter are isolated and characterized. This enable us to investigate the correlation between gene expression and the accumulation of different fatty acids composition. The knowledge and insight gained enable us to plan and design the best strategies to genetic engineering the microalgae for oil enhancement and improvement for feed, food and biofuel applications.

The microalgae genetic transformation technology established in our lab is ready to be used to express useful proteins, enzymes and other bioactive compounds of nutraceutical and pharmaceutical importance. Other current collaborative projects that uses our technology include the expression of bacteria toxin gene and herbicide resistant genes (such as EPSPS and ACCase) in selected microalgae model system to investigate its mechanism of actions at gene and cellular levels.