氮源及其浓度对三角褐指藻生长和脂肪酸组成的影响  

EFFECTS OF NITROGEN SOURCES AND CONCENTRATIONS ON THE GROWTH AND FATTY ACID COMPOSITION OF PHAEODA-CTYLUM TRICORNUTUM

作　　者：蒋汉明[1] 高坤山[1] 

机构地区：[1]汕头大学海洋生物研究所,汕头515063

出　　处：《水生生物学报》2004年第5期545-551,共7页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金项目资助 ( 3 0 0 70 85 2 )

摘　　要：为了研究氮源的类型和浓度对微藻脂肪酸组成的影响 ,用含有不同浓度NO3 -、NH4+ 、NH2 CONH2 的培养基 ,对三角褐指藻 (Phaeodactylumtricornutum)进行了培养 ,并测定了其生长和脂肪酸组成。结果表明 ,培养基中不添加氮源时 ,三角褐指藻生长缓慢 ,但多不饱和脂肪酸 (PUFAs)和C18脂肪酸 (C18∶0 ,C18∶2 (n -6) ,C18∶3 (n -6) )占总脂肪酸的比例较高 ;氮浓度较低 (<1 8mmol/L)时 ,三角褐指藻以NH4+ 为氮源 ,生长较快 ;氮浓度较高 (>3 5mmol/L)时 ,以NH2 CONH2 为氮源 ,生长较快。以NH4+ 或NH2 CONH2 为氮源时 ,EPA(Eicosapentaenoicacid)和PUFAs占总脂肪酸的比例随着其浓度的增加而上升 ;而以NO3 -为氮源时 ,EPA和PUFAs随着NO3 -浓度增加先上升后下降 ,最适NO3 -浓度为 1 8mmol/L ,此时的EPA占总脂肪酸的比例为 16 7%。EPA占干重 (w/w)的比例 ,不管是哪种氮源 ,均随着氮浓度的增加而升高 ,但是在 0 9— 3 5mmol/L之间 ,3种氮源间EPA含量差异不显著。当氮源浓度为 7 0mmol/L时 ,以NH2 CONH2 为氮源 ,EPA和PUFAs含量最高 ,分别为 2 6 %和 4 4 %。PUFAs占干重的比例随着NO3 -浓度增加而下降 ,随NH2 CONH2 浓度增加而升高 ,而受NH4+ 浓度变化的影响不显著。In order to investigate the effects of nitrogen sources and the concentrations on fatty acid composition in microalgae,a marine diatom,Phaeodactylum tricornutum,was cultured in batch with varied nitrogen sources(NO 3-,NH 4+,NH 2CONH 2)and at different concentrations.Its growth and fatty acid composition were investigated.The results showed that P.tricornutum grew poorly in the cultures without addition of any nitrogen source,however,polyunsaturated fatty acids(PUFAs)and C 18 fatty acids(C 18∶0,C 18∶2(n-6),C 18∶3(n-6))accounted for higher percentages of total fatty acids compared to those with addition of the nitrogen sources.At low concentrations of the nitrogen sources(<1.8mmol/L),the alga showed faster growth with NH 4+,and grew faster with NH 2CONH 2 at high concentrations (>3.5mmol/L).With NH 4+ or NH 2CONH 2 as nitrogen sources,EPA(eicosapentaenoic acid)and PUFAs in percentages of the total fatty acids increased when nitrogen concentrations were raised from 0.9 to 7.0mmol/L.With NO 3-,the EPA and PUFAs percentages increased to the maximum at 1.8mmol/L NO 3-,then decreased with the increased NO- 3 levels,while the highest EPA Was 16.7% of the total fatty acids.EPA content on a dry mass base(w/w)increased with the increasing nitrogen concentrations within a range of 0.9 to 7.0mmol/L regardless of the nitrogen sources.At 7.0mmol/L NH 2CONH 2,the alga achieved the highest contents(2.6%EPA and 4.4%PUFAs of the dry weight,respectively).PUFAs content on dry mass decreased with increased.NO- 3,increased with enhanced NH 2CONH 2,but showed small variation with added NH 4+.

关 键 词：氮源 三角褐指藻 生长 脂肪酸 浓度 二十碳五烯酸 多不饱和脂肪酸 

分 类 号：Q949.2[生物学—植物学] Q547