Fundamental study of glycerol-3-phosphate acyltransferase for understanding the mechanism of lipid synthesis (FRGS15-207-0448)

Ismail, Nur Faiqah and Muhamad Yussoff, Muhamad Ariff and Mohd Ashaari, Mardiana and Mohammad Noor, Normawaty and Abd Halim, Khairul Bariyyah (2019) Fundamental study of glycerol-3-phosphate acyltransferase for understanding the mechanism of lipid synthesis (FRGS15-207-0448). Project Report. UNSPECIFIED. (Unpublished)

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Abstract

GPAT is one of the enzymes that catalyzes the initial step in the TAG biosynthesis pathway, thus it is a promising target for genetic manipulation to increase lipid synthesis. Lipid content and type of fatty acids produced by microalgae are the main factors in determining the potential use of microalgae biomass due to the fact that microalgae lipid has high potential applications in food, biofuels and pharmaceutical industries. A lot of research has been performed on all aspects of microalgae lipid production including the basic research on triacylglycerol (TAG) biosynthesis pathway. Glycerol-3-phosphate acyltransferase (GPAT) is the first enzyme that catalyzes the TAG synthesis. Understanding the lipid profile at different salinity and the structural details of the GPAT enzymes in microalgae is crucial in order to understand its role in lipid synthesis. This study aims to determine biomass, lipid content and fatty acid composition from freshwater at four different salinity profile of marine C. vulgaris culture. The information on GPAT sequence is then used to aid in predicting three- dimensional (3D) GPAT protein structure using homology modeling technique. Marine Chlorella vulgaris were obtained from the Fishery Research Institute, Tanjung Demong, Besut, Terengganu. Meanwhile, freshwater C. vulgaris were isolated from Tasik Putih, Kluang, Johor. For marine C. vulgaris, they were cultured in four different salinity which were 10, 20, 30 and 40 ppt in Conwy media while freshwater. C. vulgaris was cultured in Bold Basal media. All cultures were grown and harvested during early stationary phase for biomass yield, total lipid content and fatty acid profiling analysis. The highest biomass was produced by 30 ppt marine C. vulgaris with 0.1650 ± 0.012 g/L and the lowest was 10 ppt salinity with 0.0793 ± 0.012 g/L. The highest lipid produced can reach up to 23% by 30 and 40 ppt. Lipid profiling showed that palmitic acid and linolenic acid were present on all cultures with 40 ppt culture has SFA as the highest fatty acid while PUFA was the major compound for freshwater. In this study, the 3D structure of GPAT was predicted by using GPAT protein sequence from Chlorella sorokiniana and Cucurbita moschata as the template. To the best of our knowledge, this is the first model structure of GPAT protein for microalgae. The model structure consists of 14α helices and 8β sheets. In conclusion, different culture conditions can affect the presence of fatty acid composition in Chlorella vulgaris. Besides, the structural information of the GPAT protein of Chlorella sp. obtained from this study also may be used to investigate the detailed mechanism of action of a GPAT protein and its substrates.

Item Type:	Monograph (Project Report)
Subjects:	S Agriculture > SH Aquaculture. Fisheries. Angling > SH389 Fisheries-Algae and Algae Culture
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science > Department of Biotechnology
Depositing User:	Dr Khairul Bariyyah Abd Halim
Date Deposited:	01 Dec 2019 12:13
Last Modified:	01 Dec 2019 12:13
URI:	http://irep.iium.edu.my/id/eprint/73692

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