Effects of nitrogen, phosphorus, EDTA and sodium chloride on biomass and lipid accumulation of Chaetomorpha aerea

Abstract

Marine seaweeds or macroalgae are the excellent source of bioactive compounds like proteins, vitamins, carotenoids, dietary fibres and essential fatty acids. These essential fatty acids include both the saturated and unsaturated form. The lipid content of marine macroalgae is very low (1-5%) but under stress conditions they produce up to 30-40% [1]. The fatty acids of marine macroalgae generally have linear chains and even number of carbon atoms with one or more double bonds [2]. Macroalgae have been studied for long for the production of wide range of natural chemicals like agar, agarose, carrageenan and alginates. However, they have never been looked for lipids, as energy resource [1]. Microalgae have been considered for high lipid and used for biodiesel application several times [3-6]. Stress induced changes in lipid and fatty acids profile have also been discussed for long [7-11]. But very few reports are available on macroalgal lipid and fatty acids [12-14]. The effect of nitrate and phosphates on lipidomic and other biochemical compositions of the macroalga Ulva lactuca were studied by Kumari et al. [15]. They investigated the changes in polar lipids, chlorophyll and protein content when they cultured the alga in artificial sea nutrient (ASW) medium supplemented with nitrate and phosphate. Biochemical composition of eighteen marine macroalgae belonging to Chlorophyta, Phaeophyta and Rhodophyta were studied from Okha coast, Gulf of Kutch, India [16]. They studied varied quantities of bioactive compounds like total lipid, protein, carbohydrate, phenol and amino acids. Seasonal variations in fatty acid compositions of 51 macroalgae were studied from Gulf of Mannar, Marine Biosphere Reserve of Southeast coast of India [17]. Comparative accounts of fatty acid compositions of three marine macroalgae were also studied from the coastal region of South India [18]. In our previous study we have reported the effect of nutrient and other abiotic stresses on growth and lipid accumulation in Rhizoclonium africanum [13]. Effects of nitrogen, phosphorus, EDTA and sodium chloride on biomass and lipid accumulation of Chaetomorpha aerea