臺灣鹽田分離純化之三株微細藻類鑑定及營養分析

Abstract

本研究自臺南市北門區的井仔腳鹽田中分離純化出3株綠藻 (BT、GD及RD)，並以光學顯微鏡觀察細胞型態及分析其ITS (internal transcribed spacer) region rDNA (ITS1-5.8S-ITS2) 序列後，初步鑑定BT為扁藻 (Tetraselmis marina, Cienkowski)、GD為綠色杜氏藻 (Dunaliella viridis, Téodoresco)、RD為鹽生杜氏藻 (Dunaliella salina, Téodoresco)。進一步分析這三種藻類的營養成分，顯示鹽生杜氏藻、綠色杜氏藻及扁藻的粗蛋白含量分別為：38.8%、39.4%、27.5%；粗脂質含量則為：14.4%、15.2%、3.4%，亦即杜氏藻的粗蛋白與粗脂質含量均高於扁藻。除此之外，鹽生杜氏藻經萃取後可得到細胞乾重約11% 的β-胡蘿蔔素，且其脂肪酸含量中油酸 (oleic acid；18:1n-9)、α-次亞麻油酸 (α-linolenic acid, ALA；18:3n-3)、亞麻油酸 (linoleic acid, LA；18:2n-6) 和γ-亞麻酸 (γ-linolenic acid, GLA；18:3n-6) 分別為10.1%、10.9%、5.5%、1.1%，具有進一步開發的價值。Three strains of green microalgae from the Jing-Zai-Jiao salt pans situated at Beumen in Tainan, Taiwan, were isolated, purified, and marked as RD, GD, and BT. Investigation through optical microscopy at the cellular level and through phylogenetic analysis of the internal transcribed spacer (ITS) region rDNA sequences of Dunliella and Tetraselmis indicated that the BT strain was Tetraselmis marina (Cienkowski), the GD strain was Dunaliella viridis (Téodoresco) and the RD strain was Dunaliella salina (Téodoresco). Nutritional analysis revealed that the crude protein contents of RD, GD and BT were 38.8%, 39.4% and 27.5%, respectively, while their crude lipid contents were 14.4%, 15.2% and 3.4%, respectively. The results indicated that the RD and GD provided significantly higher amounts of crude protein and crude lipid content to fry for rapid growth than the BT did. By extraction, the dry weight yield of β-carotene in the RD was found to be 11 %, while its fatty acid composition was 10.1 % oleic acid (18:1n-9), 10.9% α-linolenic acid (18:3n-3), 5.5% linoleic acid (18:2n-6) and 1.1% γ-linolenic acid (18:3n-6).