title: SALT-INDUCED ALTERATIONS IN LIPID COMPOSITION OF DIATOM NITZSCHIA LAEVIS (BACILLARIOPHYCEAE) UNDER HETEROTROPHIC CULTURE CONDITION(1).
abstract: The diatom Nitzschia laevis Hust. is a potential producer of eicosapentaenoic acid (EPA). To elucidate its cellular response to salt stress, the effects of salinity on EPA production, lipid composition, and fatty acid distribution in the lipid pool were investigated. The highest contents of total fatty acids, EPA, and polar lipids were all obtained at NaCl of 20 g · L(-1) , under which 71.3% of total EPA existed in polar lipid fractions. In N. laevis, high salt concentration might induce the decrease in neutral lipids (NLs), whereas the production of polar lipids, including phospholipids (PLs) and glycolipids (GLs), was enhanced. The degree of fatty acid unsaturation of both neutral and polar lipid fractions increased sharply when NaCl concentration increased from 10 to 20 g · L(-1) but decreased at NaCl concentration of 30 g · L(-1) . The amount of total free sterols was increased with the increase in salt concentration. All these changes in lipid and fatty acids suggested a decrease in membrane permeability and fluidity under high salt concentration, which could help the alga acclimate to the salinity stress.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongDepartment of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongSchool of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Guan-Qun
authors.initials: GQ
authors.lastname: Chen
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongDepartment of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongSchool of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yue
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongDepartment of Biology, Hong Kong Baptist University, Kowloon Tong, Hong KongSchool of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
keywords: Nitzschia laevis; eicosapentaenoic acid; fatty acid; lipid; salinity