三种海洋浮游微藻的分子鉴定及培养条件研究  

Molecular identification and culture trials of three marine microalgae

作　　者：徐娜[1,2] 逄少军[1] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071 [2]中国科学院研究生院,北京100049

出　　处：《海洋科学》2012年第10期13-25,共13页Marine Sciences

基　　金：国家科技基础条件平台-水产种质资源平台运行项目;中国科学院野生生物种质库海藻种质库平台运行项目

摘　　要：采用分子生物学手段结合形态特征对海洋中生活着的浮游单细胞海藻进行准确无误的分类鉴定,正在成为一种普遍接受的方式。这样做的前提是首先需要从海水中分离得到纯藻株,掌握它们的生活条件,获得生物量,并进而完成鉴定。作者对一株裸甲藻类似种和两株新分离的赤潮单细胞海藻进行了分离、培养和鉴定。核糖体18S RNA基因(18S rDNA)和转录单元内间隔区(ITS)序列分析结果显示这三株藻分别为共生甲藻(Symbiodinium sp.)、锥状斯氏藻(Scrippsiella trochoidea)和赤潮异弯藻(Heterosigma akashiwo)。作者以广泛使用的光密度值A680作为衡量藻体生物量变化的指标,研究了这三种藻在不同培养条件下的生长。结果表明,在批次培养中,共生甲藻、锥状斯氏藻和赤潮异弯藻的生物量都在22℃达到最大,分别为9.28×105个/mL、7.9×104个/mL和4.75×105个/mL;强光和长时间光照促进生长,但锥状斯氏藻在强光下更早进入衰退期;三种藻都表现出较强耐受盐度变化的能力,在盐度为15～36的培养液中生长良好;营养实验表明,使用882μmol/L的NO3和36.2μmol/L的PO34能够维持三种海藻的快速生长。Identification of marine microalgae using a combination of both morphology and molecular sequences has been more and more recognized to be the future direction. The prerequisite to do so is to establish pure cell culture and to obtain first-hand information of proper culture conditions including all the environmental parameters. In this investigation, we present our data on classifying three isolates from the coastal water through both molecular and morphological analyses. Analyses of the 18S ribosomal RNA gene （18S rDNA） and internal transcribed spacer （ITS） sequences showed that they are Symbiodinium sp., Scrippsiella trochoidea and Heterosigma akashiwo. To understand their growth characteristics, different culture conditions＇ effects on growth were monitored, using A680 as an estimation of biomass. The results showed that Symbiodinium sp., S. trochoidea and H. akashiwo all gave the best growth performance at 22℃, reaching 9.28× 105, 7.9× 10^4 and 4.75 × 10^5 cells/mL respectively in batch cultures. Both elevated irradiance and longer photoperiods benefited the growth. However, S. trochoidea entered recession phase earlier under higher irradiance level. All three species were shown to be able to tolerate a wide range of sa- linities （15 to 36）. Concentrations of 882 μmol/L of to be sufficient for fast accumulation of algal biomass NO3 and 36.2 μmol/L of PO4^3- in the medium were proved to be sufficient for fast accumulation of algal biomass.

关 键 词：微藻 分子鉴定 生长 赤潮藻类 

分 类 号：S968.4[农业科学—水产养殖]