菱形藻株系MD1的脂肪酸组成及其在NaHCO_3、NaCl和pH值影响下的生长特征  

Effect of different levels of NaHCO_3,NaCl and pH on the growth of a EPA-producing diatom strain

作　　者：苏娇娇[1,2] 向文洲[1] 萧邶[1] 徐少琨[1] 何慧[1] 

机构地区：[1]中国科学院南海海洋研究所,广东广州510301 [2]中国科学院研究生院,北京100049

出　　处：《热带海洋学报》2010年第6期79-85,共7页Journal of Tropical Oceanography

基　　金：广东省海洋与渔业科技项目(A200899I01);广东省科技计划项目(2009B080701093)

摘　　要：研究了具有嗜碱特性的菱形藻Nitzschia sp.(MD1)株系的脂肪酸组分、含量以及不同NaHCO3、NaCl和pH值水平下对其生长的影响。GC-MS测定结果显示,在NaHCO3浓度为0.2mol.L-1、NaCl浓度为30g.L-1、初始pH值为9.5时,MD1的EPA含量占干重的3.02%,占总脂肪酸的比例为17.93%。生长测定结果表明,MD1具有极强的耐碱能力,其生长适宜的NaHCO3浓度为0.1—0.2mol.L-1,在0.3mol.L-1的NaHCO3浓度下仍能良好生长;MD1最适的起始pH值范围为7.5—9.5,其生长速率在pH7.5与pH9.5之间没有显著性差异(P>0.05),可以耐受pH值为11.5的高碱性环境并保持较好的生长;MD1显示广盐适应性,NaCl浓度在0g.L-1时获得最大比生长速率,在30—40g.L-1时对其生长没有显著影响(P>0.05),在NaCl浓度30g.L-1、pH 8.5—9.5及NaHCO3 0.2mol.L-1时,获得了最大比生长速率0.56d-1。由此可见,MD1可望具有进行大规模培养开发EPA的前景。In this study,we investigated the composition and content of fatty acids,and the effects of different levels of Na-HCO3,NaCl and pH on an alkalophilic diatom strain,Nitzschia sp.MD1.We showed that MD1 contained 3.02% EPA in dry weight biomass,which was 17.93% of the total fatty acids.It was indicated that the optimal range of NaHCO3 for MD1 growth was between 0.1-0.2 M,and that MD1 showed a good growth even when NaHCO3 was below 0.3.The optimal range of initial pH for MD1 growth was between 7.5 and 9.5,and that MD1 maintained a considerable growth even when initial pH was 11.5.It was also shown that MD1 exhibited adaptation to a wide range of salinity,which brought about no obvious difference in the growth of MD1 when NaCl was between 0-40g·L-1.The maximum specific growth rate of MD1 reached 0.56d-1 at 0.2mol·L-1 of NaHCO3,30g·L-1 of NaCl,and 8.5-9.5 of pH.These results present a prospective future for large-scale cultiva-tion and EPA production of MD1.

关 键 词：菱形藻Nitzschia sp. 嗜碱特性 pH NAHCO3 EPA 

分 类 号：Q945[生物学—植物学] Q949.9